Wordle Start Words

Having played a similar game years ago, as soon as I learned about Wordle, I wanted to figure out a set of words to use as starting guesses. My thought is to:

  1. Maximize the number of unique letters guessed.
  2. Prioritize the more frequently used letters.

The first means I want to pick words that don't repeat letters, that's pretty simple. The second requires first getting data on letter frequency. There's a wikipedia article on letter frequency that has two frequency tables, one for letter use in English text and another for letter use in dictionary words.

ETAOI NSHRD LCUMW FGYPB VKXJQ Z - text frequency
ESIAR NTOLC DUGPM KHBYF VWZXQ J - dictionary frequency

The text frequency list is skewed by common words, so the dictionary word frequency seems more appropriate for this application. Even better would be to only consider 5-letter words. I have an electronic version of the Official Scrabble Players Dictionary, so I filtered that to find 8,183 five-letter words and used that to compute letter frequency.

SEARO ILTND UCPYM HGBKF WVZXJ Q - OSPD 5-letter word frequency

The obvious way to start is with a word that hits all five of the most frequently used letters, AROSE for example. That's great for a first guess, but even with that word, it's not common for the first word to give enough information to start guessing the answer, and it's going to be quite constrained to pick follow-up words that don't repeat characters.

This calls for a program to create a list of three to four words that achives the goals stated above. Considering all possible choices for 4 words out of 8,183 would take a lot of computing time and would mostly be churning through terrible word combinations. To reduce the number of combinations to look at, I further filtered the list to words that don't repeat letters, which dropped the count down to 5,404 words. From that list, I pulled out four groups of words. Group 1 is words that have at least three letters in the top 5 (SEARO), group 2 has at least three letters in the next five letters (ILTND), and so forth.

Group 1: 197 words
Group 2: 448 words
Group 3: 155 words
Group 4: 8 words

Not surprisingly, group 5 is empty: there are no words that have 5 distinct letters with 3 of them from WVZXJ.

I wrote a Python program that examines all combinations of one word from each of those four groups and ranks them according to how well they cover a lot of letters while prioritizing the high frequency letters early. That found 720 sets of words tied with the best stats: they get 4 of the top 5 letters on the first word, pick up the fifth and get 9 of the top 10 with the second word and get all of the top 15 with the third word. From there, it gets more difficult to avoid repeating letters; all of the vowels and the most common consonanants have been used. The best fourth words I've found pick up just three more new letters. For example:

AEONS DIRTY CLUMP BOUGH

AEONS gets all but R from the first set of most frequent letters (searo). DIRTY picks up the R, all but L from the second 5 (iltnd), plus Y from the third. CLUMP takes care of the R and the rest of the third group (ucpym). That gives us info in the top 15 letters with three guesses. BOUGH only adds 3 letters, but it's rare to get to the fourth word before it's time to start guessing what the answer is, in fact the first two often give enough to start working on the answer.

I made some simplifying assumptions to reduce the search space. Perhaps a different approach would lead to a better set, but I'm pretty happy with the results.

Most of the word lists consist of obscure words. Also different sets postpone different letters for later words. The full list of word sets is below. Find your favorite or use a different set every day for almost two years.

ACRES TONDI LUMPY BHANG
ACRES TONDI LUMPY BIGHT
ACRES TONDI LUMPY BOUGH
ACRES TONDI LUMPY BRUGH
ACRES TONDI LUMPY BURGH
ACRES TONDI PLUMY BHANG
ACRES TONDI PLUMY BIGHT
ACRES TONDI PLUMY BOUGH
ACRES TONDI PLUMY BRUGH
ACRES TONDI PLUMY BURGH
AEONS DIRTY CLUMP BHANG
AEONS DIRTY CLUMP BIGHT
AEONS DIRTY CLUMP BOUGH
AEONS DIRTY CLUMP BRUGH
AEONS DIRTY CLUMP BURGH
ARLES ONTIC DUMPY BHANG
ARLES ONTIC DUMPY BIGHT
ARLES ONTIC DUMPY BOUGH
ARLES ONTIC DUMPY BRUGH
ARLES ONTIC DUMPY BURGH
ARLES TONIC DUMPY BHANG
ARLES TONIC DUMPY BIGHT
ARLES TONIC DUMPY BOUGH
ARLES TONIC DUMPY BRUGH
ARLES TONIC DUMPY BURGH
ARSON CITED LUMPY BHANG
ARSON CITED LUMPY BIGHT
ARSON CITED LUMPY BOUGH
ARSON CITED LUMPY BRUGH
ARSON CITED LUMPY BURGH
ARSON CITED PLUMY BHANG
ARSON CITED PLUMY BIGHT
ARSON CITED PLUMY BOUGH
ARSON CITED PLUMY BRUGH
ARSON CITED PLUMY BURGH
ARSON DEITY CLUMP BHANG
ARSON DEITY CLUMP BIGHT
ARSON DEITY CLUMP BOUGH
ARSON DEITY CLUMP BRUGH
ARSON DEITY CLUMP BURGH
ARSON EDICT LUMPY BHANG
ARSON EDICT LUMPY BIGHT
ARSON EDICT LUMPY BOUGH
ARSON EDICT LUMPY BRUGH
ARSON EDICT LUMPY BURGH
ARSON EDICT PLUMY BHANG
ARSON EDICT PLUMY BIGHT
ARSON EDICT PLUMY BOUGH
ARSON EDICT PLUMY BRUGH
ARSON EDICT PLUMY BURGH
ARSON TELIC DUMPY BHANG
ARSON TELIC DUMPY BIGHT
ARSON TELIC DUMPY BOUGH
ARSON TELIC DUMPY BRUGH
ARSON TELIC DUMPY BURGH
ASTER COLIN DUMPY BHANG
ASTER COLIN DUMPY BIGHT
ASTER COLIN DUMPY BOUGH
ASTER COLIN DUMPY BRUGH
ASTER COLIN DUMPY BURGH
ASTER NICOL DUMPY BHANG
ASTER NICOL DUMPY BIGHT
ASTER NICOL DUMPY BOUGH
ASTER NICOL DUMPY BRUGH
ASTER NICOL DUMPY BURGH
CARES TONDI LUMPY BHANG
CARES TONDI LUMPY BIGHT
CARES TONDI LUMPY BOUGH
CARES TONDI LUMPY BRUGH
CARES TONDI LUMPY BURGH
CARES TONDI PLUMY BHANG
CARES TONDI PLUMY BIGHT
CARES TONDI PLUMY BOUGH
CARES TONDI PLUMY BRUGH
CARES TONDI PLUMY BURGH
CARSE TONDI LUMPY BHANG
CARSE TONDI LUMPY BIGHT
CARSE TONDI LUMPY BOUGH
CARSE TONDI LUMPY BRUGH
CARSE TONDI LUMPY BURGH
CARSE TONDI PLUMY BHANG
CARSE TONDI PLUMY BIGHT
CARSE TONDI PLUMY BOUGH
CARSE TONDI PLUMY BRUGH
CARSE TONDI PLUMY BURGH
DARES ONTIC LUMPY BHANG
DARES ONTIC LUMPY BIGHT
DARES ONTIC LUMPY BOUGH
DARES ONTIC LUMPY BRUGH
DARES ONTIC LUMPY BURGH
DARES ONTIC PLUMY BHANG
DARES ONTIC PLUMY BIGHT
DARES ONTIC PLUMY BOUGH
DARES ONTIC PLUMY BRUGH
DARES ONTIC PLUMY BURGH
DARES TONIC LUMPY BHANG
DARES TONIC LUMPY BIGHT
DARES TONIC LUMPY BOUGH
DARES TONIC LUMPY BRUGH
DARES TONIC LUMPY BURGH
DARES TONIC PLUMY BHANG
DARES TONIC PLUMY BIGHT
DARES TONIC PLUMY BOUGH
DARES TONIC PLUMY BRUGH
DARES TONIC PLUMY BURGH
DEARS ONTIC LUMPY BHANG
DEARS ONTIC LUMPY BIGHT
DEARS ONTIC LUMPY BOUGH
DEARS ONTIC LUMPY BRUGH
DEARS ONTIC LUMPY BURGH
DEARS ONTIC PLUMY BHANG
DEARS ONTIC PLUMY BIGHT
DEARS ONTIC PLUMY BOUGH
DEARS ONTIC PLUMY BRUGH
DEARS ONTIC PLUMY BURGH
DEARS TONIC LUMPY BHANG
DEARS TONIC LUMPY BIGHT
DEARS TONIC LUMPY BOUGH
DEARS TONIC LUMPY BRUGH
DEARS TONIC LUMPY BURGH
DEARS TONIC PLUMY BHANG
DEARS TONIC PLUMY BIGHT
DEARS TONIC PLUMY BOUGH
DEARS TONIC PLUMY BRUGH
DEARS TONIC PLUMY BURGH
DOERS ACTIN LUMPY BHANG
DOERS ACTIN LUMPY BIGHT
DOERS ACTIN LUMPY BOUGH
DOERS ACTIN LUMPY BRUGH
DOERS ACTIN LUMPY BURGH
DOERS ACTIN PLUMY BHANG
DOERS ACTIN PLUMY BIGHT
DOERS ACTIN PLUMY BOUGH
DOERS ACTIN PLUMY BRUGH
DOERS ACTIN PLUMY BURGH
DOERS ANTIC LUMPY BHANG
DOERS ANTIC LUMPY BIGHT
DOERS ANTIC LUMPY BOUGH
DOERS ANTIC LUMPY BRUGH
DOERS ANTIC LUMPY BURGH
DOERS ANTIC PLUMY BHANG
DOERS ANTIC PLUMY BIGHT
DOERS ANTIC PLUMY BOUGH
DOERS ANTIC PLUMY BRUGH
DOERS ANTIC PLUMY BURGH
DOSER ACTIN LUMPY BHANG
DOSER ACTIN LUMPY BIGHT
DOSER ACTIN LUMPY BOUGH
DOSER ACTIN LUMPY BRUGH
DOSER ACTIN LUMPY BURGH
DOSER ACTIN PLUMY BHANG
DOSER ACTIN PLUMY BIGHT
DOSER ACTIN PLUMY BOUGH
DOSER ACTIN PLUMY BRUGH
DOSER ACTIN PLUMY BURGH
DOSER ANTIC LUMPY BHANG
DOSER ANTIC LUMPY BIGHT
DOSER ANTIC LUMPY BOUGH
DOSER ANTIC LUMPY BRUGH
DOSER ANTIC LUMPY BURGH
DOSER ANTIC PLUMY BHANG
DOSER ANTIC PLUMY BIGHT
DOSER ANTIC PLUMY BOUGH
DOSER ANTIC PLUMY BRUGH
DOSER ANTIC PLUMY BURGH
EARLS ONTIC DUMPY BHANG
EARLS ONTIC DUMPY BIGHT
EARLS ONTIC DUMPY BOUGH
EARLS ONTIC DUMPY BRUGH
EARLS ONTIC DUMPY BURGH
EARLS TONIC DUMPY BHANG
EARLS TONIC DUMPY BIGHT
EARLS TONIC DUMPY BOUGH
EARLS TONIC DUMPY BRUGH
EARLS TONIC DUMPY BURGH
EARNS DICOT LUMPY BHANG
EARNS DICOT LUMPY BIGHT
EARNS DICOT LUMPY BOUGH
EARNS DICOT LUMPY BRUGH
EARNS DICOT LUMPY BURGH
EARNS DICOT PLUMY BHANG
EARNS DICOT PLUMY BIGHT
EARNS DICOT PLUMY BOUGH
EARNS DICOT PLUMY BRUGH
EARNS DICOT PLUMY BURGH
EARNS LOTIC DUMPY BHANG
EARNS LOTIC DUMPY BIGHT
EARNS LOTIC DUMPY BOUGH
EARNS LOTIC DUMPY BRUGH
EARNS LOTIC DUMPY BURGH
ESCAR TONDI LUMPY BHANG
ESCAR TONDI LUMPY BIGHT
ESCAR TONDI LUMPY BOUGH
ESCAR TONDI LUMPY BRUGH
ESCAR TONDI LUMPY BURGH
ESCAR TONDI PLUMY BHANG
ESCAR TONDI PLUMY BIGHT
ESCAR TONDI PLUMY BOUGH
ESCAR TONDI PLUMY BRUGH
ESCAR TONDI PLUMY BURGH
EYRAS TONDI CLUMP BHANG
EYRAS TONDI CLUMP BIGHT
EYRAS TONDI CLUMP BOUGH
EYRAS TONDI CLUMP BRUGH
EYRAS TONDI CLUMP BURGH
LARES ONTIC DUMPY BHANG
LARES ONTIC DUMPY BIGHT
LARES ONTIC DUMPY BOUGH
LARES ONTIC DUMPY BRUGH
LARES ONTIC DUMPY BURGH
LARES TONIC DUMPY BHANG
LARES TONIC DUMPY BIGHT
LARES TONIC DUMPY BOUGH
LARES TONIC DUMPY BRUGH
LARES TONIC DUMPY BURGH
LASER ONTIC DUMPY BHANG
LASER ONTIC DUMPY BIGHT
LASER ONTIC DUMPY BOUGH
LASER ONTIC DUMPY BRUGH
LASER ONTIC DUMPY BURGH
LASER TONIC DUMPY BHANG
LASER TONIC DUMPY BIGHT
LASER TONIC DUMPY BOUGH
LASER TONIC DUMPY BRUGH
LASER TONIC DUMPY BURGH
LEARS ONTIC DUMPY BHANG
LEARS ONTIC DUMPY BIGHT
LEARS ONTIC DUMPY BOUGH
LEARS ONTIC DUMPY BRUGH
LEARS ONTIC DUMPY BURGH
LEARS TONIC DUMPY BHANG
LEARS TONIC DUMPY BIGHT
LEARS TONIC DUMPY BOUGH
LEARS TONIC DUMPY BRUGH
LEARS TONIC DUMPY BURGH
LORES ACTIN DUMPY BHANG
LORES ACTIN DUMPY BIGHT
LORES ACTIN DUMPY BOUGH
LORES ACTIN DUMPY BRUGH
LORES ACTIN DUMPY BURGH
LORES ANTIC DUMPY BHANG
LORES ANTIC DUMPY BIGHT
LORES ANTIC DUMPY BOUGH
LORES ANTIC DUMPY BRUGH
LORES ANTIC DUMPY BURGH
LOSER ACTIN DUMPY BHANG
LOSER ACTIN DUMPY BIGHT
LOSER ACTIN DUMPY BOUGH
LOSER ACTIN DUMPY BRUGH
LOSER ACTIN DUMPY BURGH
LOSER ANTIC DUMPY BHANG
LOSER ANTIC DUMPY BIGHT
LOSER ANTIC DUMPY BOUGH
LOSER ANTIC DUMPY BRUGH
LOSER ANTIC DUMPY BURGH
NARES DICOT LUMPY BHANG
NARES DICOT LUMPY BIGHT
NARES DICOT LUMPY BOUGH
NARES DICOT LUMPY BRUGH
NARES DICOT LUMPY BURGH
NARES DICOT PLUMY BHANG
NARES DICOT PLUMY BIGHT
NARES DICOT PLUMY BOUGH
NARES DICOT PLUMY BRUGH
NARES DICOT PLUMY BURGH
NARES LOTIC DUMPY BHANG
NARES LOTIC DUMPY BIGHT
NARES LOTIC DUMPY BOUGH
NARES LOTIC DUMPY BRUGH
NARES LOTIC DUMPY BURGH
NEARS DICOT LUMPY BHANG
NEARS DICOT LUMPY BIGHT
NEARS DICOT LUMPY BOUGH
NEARS DICOT LUMPY BRUGH
NEARS DICOT LUMPY BURGH
NEARS DICOT PLUMY BHANG
NEARS DICOT PLUMY BIGHT
NEARS DICOT PLUMY BOUGH
NEARS DICOT PLUMY BRUGH
NEARS DICOT PLUMY BURGH
NEARS LOTIC DUMPY BHANG
NEARS LOTIC DUMPY BIGHT
NEARS LOTIC DUMPY BOUGH
NEARS LOTIC DUMPY BRUGH
NEARS LOTIC DUMPY BURGH
OCREA DINTS LUMPY BHANG
OCREA DINTS LUMPY BIGHT
OCREA DINTS LUMPY BOUGH
OCREA DINTS LUMPY BRUGH
OCREA DINTS LUMPY BURGH
OCREA DINTS PLUMY BHANG
OCREA DINTS PLUMY BIGHT
OCREA DINTS PLUMY BOUGH
OCREA DINTS PLUMY BRUGH
OCREA DINTS PLUMY BURGH
OCREA LINTS DUMPY BHANG
OCREA LINTS DUMPY BIGHT
OCREA LINTS DUMPY BOUGH
OCREA LINTS DUMPY BRUGH
OCREA LINTS DUMPY BURGH
ORCAS INLET DUMPY BHANG
ORCAS INLET DUMPY BIGHT
ORCAS INLET DUMPY BOUGH
ORCAS INLET DUMPY BRUGH
ORCAS INLET DUMPY BURGH
ORCAS TEIND LUMPY BHANG
ORCAS TEIND LUMPY BIGHT
ORCAS TEIND LUMPY BOUGH
ORCAS TEIND LUMPY BRUGH
ORCAS TEIND LUMPY BURGH
ORCAS TEIND PLUMY BHANG
ORCAS TEIND PLUMY BIGHT
ORCAS TEIND PLUMY BOUGH
ORCAS TEIND PLUMY BRUGH
ORCAS TEIND PLUMY BURGH
ORCAS TINED LUMPY BHANG
ORCAS TINED LUMPY BIGHT
ORCAS TINED LUMPY BOUGH
ORCAS TINED LUMPY BRUGH
ORCAS TINED LUMPY BURGH
ORCAS TINED PLUMY BHANG
ORCAS TINED PLUMY BIGHT
ORCAS TINED PLUMY BOUGH
ORCAS TINED PLUMY BRUGH
ORCAS TINED PLUMY BURGH
ORLES ACTIN DUMPY BHANG
ORLES ACTIN DUMPY BIGHT
ORLES ACTIN DUMPY BOUGH
ORLES ACTIN DUMPY BRUGH
ORLES ACTIN DUMPY BURGH
ORLES ANTIC DUMPY BHANG
ORLES ANTIC DUMPY BIGHT
ORLES ANTIC DUMPY BOUGH
ORLES ANTIC DUMPY BRUGH
ORLES ANTIC DUMPY BURGH
RACES TONDI LUMPY BHANG
RACES TONDI LUMPY BIGHT
RACES TONDI LUMPY BOUGH
RACES TONDI LUMPY BRUGH
RACES TONDI LUMPY BURGH
RACES TONDI PLUMY BHANG
RACES TONDI PLUMY BIGHT
RACES TONDI PLUMY BOUGH
RACES TONDI PLUMY BRUGH
RACES TONDI PLUMY BURGH
RALES ONTIC DUMPY BHANG
RALES ONTIC DUMPY BIGHT
RALES ONTIC DUMPY BOUGH
RALES ONTIC DUMPY BRUGH
RALES ONTIC DUMPY BURGH
RALES TONIC DUMPY BHANG
RALES TONIC DUMPY BIGHT
RALES TONIC DUMPY BOUGH
RALES TONIC DUMPY BRUGH
RALES TONIC DUMPY BURGH
RASED ONTIC LUMPY BHANG
RASED ONTIC LUMPY BIGHT
RASED ONTIC LUMPY BOUGH
RASED ONTIC LUMPY BRUGH
RASED ONTIC LUMPY BURGH
RASED ONTIC PLUMY BHANG
RASED ONTIC PLUMY BIGHT
RASED ONTIC PLUMY BOUGH
RASED ONTIC PLUMY BRUGH
RASED ONTIC PLUMY BURGH
RASED TONIC LUMPY BHANG
RASED TONIC LUMPY BIGHT
RASED TONIC LUMPY BOUGH
RASED TONIC LUMPY BRUGH
RASED TONIC LUMPY BURGH
RASED TONIC PLUMY BHANG
RASED TONIC PLUMY BIGHT
RASED TONIC PLUMY BOUGH
RASED TONIC PLUMY BRUGH
RASED TONIC PLUMY BURGH
RATES COLIN DUMPY BHANG
RATES COLIN DUMPY BIGHT
RATES COLIN DUMPY BOUGH
RATES COLIN DUMPY BRUGH
RATES COLIN DUMPY BURGH
RATES NICOL DUMPY BHANG
RATES NICOL DUMPY BIGHT
RATES NICOL DUMPY BOUGH
RATES NICOL DUMPY BRUGH
RATES NICOL DUMPY BURGH
RATOS CLINE DUMPY BHANG
RATOS CLINE DUMPY BIGHT
RATOS CLINE DUMPY BOUGH
RATOS CLINE DUMPY BRUGH
RATOS CLINE DUMPY BURGH
READS ONTIC LUMPY BHANG
READS ONTIC LUMPY BIGHT
READS ONTIC LUMPY BOUGH
READS ONTIC LUMPY BRUGH
READS ONTIC LUMPY BURGH
READS ONTIC PLUMY BHANG
READS ONTIC PLUMY BIGHT
READS ONTIC PLUMY BOUGH
READS ONTIC PLUMY BRUGH
READS ONTIC PLUMY BURGH
READS TONIC LUMPY BHANG
READS TONIC LUMPY BIGHT
READS TONIC LUMPY BOUGH
READS TONIC LUMPY BRUGH
READS TONIC LUMPY BURGH
READS TONIC PLUMY BHANG
READS TONIC PLUMY BIGHT
READS TONIC PLUMY BOUGH
READS TONIC PLUMY BRUGH
READS TONIC PLUMY BURGH
REALS ONTIC DUMPY BHANG
REALS ONTIC DUMPY BIGHT
REALS ONTIC DUMPY BOUGH
REALS ONTIC DUMPY BRUGH
REALS ONTIC DUMPY BURGH
REALS TONIC DUMPY BHANG
REALS TONIC DUMPY BIGHT
REALS TONIC DUMPY BOUGH
REALS TONIC DUMPY BRUGH
REALS TONIC DUMPY BURGH
REDOS ACTIN LUMPY BHANG
REDOS ACTIN LUMPY BIGHT
REDOS ACTIN LUMPY BOUGH
REDOS ACTIN LUMPY BRUGH
REDOS ACTIN LUMPY BURGH
REDOS ACTIN PLUMY BHANG
REDOS ACTIN PLUMY BIGHT
REDOS ACTIN PLUMY BOUGH
REDOS ACTIN PLUMY BRUGH
REDOS ACTIN PLUMY BURGH
REDOS ANTIC LUMPY BHANG
REDOS ANTIC LUMPY BIGHT
REDOS ANTIC LUMPY BOUGH
REDOS ANTIC LUMPY BRUGH
REDOS ANTIC LUMPY BURGH
REDOS ANTIC PLUMY BHANG
REDOS ANTIC PLUMY BIGHT
REDOS ANTIC PLUMY BOUGH
REDOS ANTIC PLUMY BRUGH
REDOS ANTIC PLUMY BURGH
RESAY TONDI CLUMP BHANG
RESAY TONDI CLUMP BIGHT
RESAY TONDI CLUMP BOUGH
RESAY TONDI CLUMP BRUGH
RESAY TONDI CLUMP BURGH
ROANS CITED LUMPY BHANG
ROANS CITED LUMPY BIGHT
ROANS CITED LUMPY BOUGH
ROANS CITED LUMPY BRUGH
ROANS CITED LUMPY BURGH
ROANS CITED PLUMY BHANG
ROANS CITED PLUMY BIGHT
ROANS CITED PLUMY BOUGH
ROANS CITED PLUMY BRUGH
ROANS CITED PLUMY BURGH
ROANS DEITY CLUMP BHANG
ROANS DEITY CLUMP BIGHT
ROANS DEITY CLUMP BOUGH
ROANS DEITY CLUMP BRUGH
ROANS DEITY CLUMP BURGH
ROANS EDICT LUMPY BHANG
ROANS EDICT LUMPY BIGHT
ROANS EDICT LUMPY BOUGH
ROANS EDICT LUMPY BRUGH
ROANS EDICT LUMPY BURGH
ROANS EDICT PLUMY BHANG
ROANS EDICT PLUMY BIGHT
ROANS EDICT PLUMY BOUGH
ROANS EDICT PLUMY BRUGH
ROANS EDICT PLUMY BURGH
ROANS TELIC DUMPY BHANG
ROANS TELIC DUMPY BIGHT
ROANS TELIC DUMPY BOUGH
ROANS TELIC DUMPY BRUGH
ROANS TELIC DUMPY BURGH
ROAST CLINE DUMPY BHANG
ROAST CLINE DUMPY BIGHT
ROAST CLINE DUMPY BOUGH
ROAST CLINE DUMPY BRUGH
ROAST CLINE DUMPY BURGH
ROLES ACTIN DUMPY BHANG
ROLES ACTIN DUMPY BIGHT
ROLES ACTIN DUMPY BOUGH
ROLES ACTIN DUMPY BRUGH
ROLES ACTIN DUMPY BURGH
ROLES ANTIC DUMPY BHANG
ROLES ANTIC DUMPY BIGHT
ROLES ANTIC DUMPY BOUGH
ROLES ANTIC DUMPY BRUGH
ROLES ANTIC DUMPY BURGH
ROSED ACTIN LUMPY BHANG
ROSED ACTIN LUMPY BIGHT
ROSED ACTIN LUMPY BOUGH
ROSED ACTIN LUMPY BRUGH
ROSED ACTIN LUMPY BURGH
ROSED ACTIN PLUMY BHANG
ROSED ACTIN PLUMY BIGHT
ROSED ACTIN PLUMY BOUGH
ROSED ACTIN PLUMY BRUGH
ROSED ACTIN PLUMY BURGH
ROSED ANTIC LUMPY BHANG
ROSED ANTIC LUMPY BIGHT
ROSED ANTIC LUMPY BOUGH
ROSED ANTIC LUMPY BRUGH
ROSED ANTIC LUMPY BURGH
ROSED ANTIC PLUMY BHANG
ROSED ANTIC PLUMY BIGHT
ROSED ANTIC PLUMY BOUGH
ROSED ANTIC PLUMY BRUGH
ROSED ANTIC PLUMY BURGH
ROSET LINAC DUMPY BHANG
ROSET LINAC DUMPY BIGHT
ROSET LINAC DUMPY BOUGH
ROSET LINAC DUMPY BRUGH
ROSET LINAC DUMPY BURGH
ROTAS CLINE DUMPY BHANG
ROTAS CLINE DUMPY BIGHT
ROTAS CLINE DUMPY BOUGH
ROTAS CLINE DUMPY BRUGH
ROTAS CLINE DUMPY BURGH
ROTES LINAC DUMPY BHANG
ROTES LINAC DUMPY BIGHT
ROTES LINAC DUMPY BOUGH
ROTES LINAC DUMPY BRUGH
ROTES LINAC DUMPY BURGH
SANER DICOT LUMPY BHANG
SANER DICOT LUMPY BIGHT
SANER DICOT LUMPY BOUGH
SANER DICOT LUMPY BRUGH
SANER DICOT LUMPY BURGH
SANER DICOT PLUMY BHANG
SANER DICOT PLUMY BIGHT
SANER DICOT PLUMY BOUGH
SANER DICOT PLUMY BRUGH
SANER DICOT PLUMY BURGH
SANER LOTIC DUMPY BHANG
SANER LOTIC DUMPY BIGHT
SANER LOTIC DUMPY BOUGH
SANER LOTIC DUMPY BRUGH
SANER LOTIC DUMPY BURGH
SAYER TONDI CLUMP BHANG
SAYER TONDI CLUMP BIGHT
SAYER TONDI CLUMP BOUGH
SAYER TONDI CLUMP BRUGH
SAYER TONDI CLUMP BURGH
SCARE TONDI LUMPY BHANG
SCARE TONDI LUMPY BIGHT
SCARE TONDI LUMPY BOUGH
SCARE TONDI LUMPY BRUGH
SCARE TONDI LUMPY BURGH
SCARE TONDI PLUMY BHANG
SCARE TONDI PLUMY BIGHT
SCARE TONDI PLUMY BOUGH
SCARE TONDI PLUMY BRUGH
SCARE TONDI PLUMY BURGH
SENOR DICTA LUMPY BHANG
SENOR DICTA LUMPY BIGHT
SENOR DICTA LUMPY BOUGH
SENOR DICTA LUMPY BRUGH
SENOR DICTA LUMPY BURGH
SENOR DICTA PLUMY BHANG
SENOR DICTA PLUMY BIGHT
SENOR DICTA PLUMY BOUGH
SENOR DICTA PLUMY BRUGH
SENOR DICTA PLUMY BURGH
SENOR TICAL DUMPY BHANG
SENOR TICAL DUMPY BIGHT
SENOR TICAL DUMPY BOUGH
SENOR TICAL DUMPY BRUGH
SENOR TICAL DUMPY BURGH
SERAC TONDI LUMPY BHANG
SERAC TONDI LUMPY BIGHT
SERAC TONDI LUMPY BOUGH
SERAC TONDI LUMPY BRUGH
SERAC TONDI LUMPY BURGH
SERAC TONDI PLUMY BHANG
SERAC TONDI PLUMY BIGHT
SERAC TONDI PLUMY BOUGH
SERAC TONDI PLUMY BRUGH
SERAC TONDI PLUMY BURGH
SERAL ONTIC DUMPY BHANG
SERAL ONTIC DUMPY BIGHT
SERAL ONTIC DUMPY BOUGH
SERAL ONTIC DUMPY BRUGH
SERAL ONTIC DUMPY BURGH
SERAL TONIC DUMPY BHANG
SERAL TONIC DUMPY BIGHT
SERAL TONIC DUMPY BOUGH
SERAL TONIC DUMPY BRUGH
SERAL TONIC DUMPY BURGH
SNARE DICOT LUMPY BHANG
SNARE DICOT LUMPY BIGHT
SNARE DICOT LUMPY BOUGH
SNARE DICOT LUMPY BRUGH
SNARE DICOT LUMPY BURGH
SNARE DICOT PLUMY BHANG
SNARE DICOT PLUMY BIGHT
SNARE DICOT PLUMY BOUGH
SNARE DICOT PLUMY BRUGH
SNARE DICOT PLUMY BURGH
SNARE LOTIC DUMPY BHANG
SNARE LOTIC DUMPY BIGHT
SNARE LOTIC DUMPY BOUGH
SNARE LOTIC DUMPY BRUGH
SNARE LOTIC DUMPY BURGH
SNORE DICTA LUMPY BHANG
SNORE DICTA LUMPY BIGHT
SNORE DICTA LUMPY BOUGH
SNORE DICTA LUMPY BRUGH
SNORE DICTA LUMPY BURGH
SNORE DICTA PLUMY BHANG
SNORE DICTA PLUMY BIGHT
SNORE DICTA PLUMY BOUGH
SNORE DICTA PLUMY BRUGH
SNORE DICTA PLUMY BURGH
SNORE TICAL DUMPY BHANG
SNORE TICAL DUMPY BIGHT
SNORE TICAL DUMPY BOUGH
SNORE TICAL DUMPY BRUGH
SNORE TICAL DUMPY BURGH
SONAR CITED LUMPY BHANG
SONAR CITED LUMPY BIGHT
SONAR CITED LUMPY BOUGH
SONAR CITED LUMPY BRUGH
SONAR CITED LUMPY BURGH
SONAR CITED PLUMY BHANG
SONAR CITED PLUMY BIGHT
SONAR CITED PLUMY BOUGH
SONAR CITED PLUMY BRUGH
SONAR CITED PLUMY BURGH
SONAR DEITY CLUMP BHANG
SONAR DEITY CLUMP BIGHT
SONAR DEITY CLUMP BOUGH
SONAR DEITY CLUMP BRUGH
SONAR DEITY CLUMP BURGH
SONAR EDICT LUMPY BHANG
SONAR EDICT LUMPY BIGHT
SONAR EDICT LUMPY BOUGH
SONAR EDICT LUMPY BRUGH
SONAR EDICT LUMPY BURGH
SONAR EDICT PLUMY BHANG
SONAR EDICT PLUMY BIGHT
SONAR EDICT PLUMY BOUGH
SONAR EDICT PLUMY BRUGH
SONAR EDICT PLUMY BURGH
SONAR TELIC DUMPY BHANG
SONAR TELIC DUMPY BIGHT
SONAR TELIC DUMPY BOUGH
SONAR TELIC DUMPY BRUGH
SONAR TELIC DUMPY BURGH
SOREL ACTIN DUMPY BHANG
SOREL ACTIN DUMPY BIGHT
SOREL ACTIN DUMPY BOUGH
SOREL ACTIN DUMPY BRUGH
SOREL ACTIN DUMPY BURGH
SOREL ANTIC DUMPY BHANG
SOREL ANTIC DUMPY BIGHT
SOREL ANTIC DUMPY BOUGH
SOREL ANTIC DUMPY BRUGH
SOREL ANTIC DUMPY BURGH
STARE COLIN DUMPY BHANG
STARE COLIN DUMPY BIGHT
STARE COLIN DUMPY BOUGH
STARE COLIN DUMPY BRUGH
STARE COLIN DUMPY BURGH
STARE NICOL DUMPY BHANG
STARE NICOL DUMPY BIGHT
STARE NICOL DUMPY BOUGH
STARE NICOL DUMPY BRUGH
STARE NICOL DUMPY BURGH
STORE LINAC DUMPY BHANG
STORE LINAC DUMPY BIGHT
STORE LINAC DUMPY BOUGH
STORE LINAC DUMPY BRUGH
STORE LINAC DUMPY BURGH
TARES COLIN DUMPY BHANG
TARES COLIN DUMPY BIGHT
TARES COLIN DUMPY BOUGH
TARES COLIN DUMPY BRUGH
TARES COLIN DUMPY BURGH
TARES NICOL DUMPY BHANG
TARES NICOL DUMPY BIGHT
TARES NICOL DUMPY BOUGH
TARES NICOL DUMPY BRUGH
TARES NICOL DUMPY BURGH
TAROS CLINE DUMPY BHANG
TAROS CLINE DUMPY BIGHT
TAROS CLINE DUMPY BOUGH
TAROS CLINE DUMPY BRUGH
TAROS CLINE DUMPY BURGH
TEARS COLIN DUMPY BHANG
TEARS COLIN DUMPY BIGHT
TEARS COLIN DUMPY BOUGH
TEARS COLIN DUMPY BRUGH
TEARS COLIN DUMPY BURGH
TEARS NICOL DUMPY BHANG
TEARS NICOL DUMPY BIGHT
TEARS NICOL DUMPY BOUGH
TEARS NICOL DUMPY BRUGH
TEARS NICOL DUMPY BURGH
TORAS CLINE DUMPY BHANG
TORAS CLINE DUMPY BIGHT
TORAS CLINE DUMPY BOUGH
TORAS CLINE DUMPY BRUGH
TORAS CLINE DUMPY BURGH
TORES LINAC DUMPY BHANG
TORES LINAC DUMPY BIGHT
TORES LINAC DUMPY BOUGH
TORES LINAC DUMPY BRUGH
TORES LINAC DUMPY BURGH
TORSE LINAC DUMPY BHANG
TORSE LINAC DUMPY BIGHT
TORSE LINAC DUMPY BOUGH
TORSE LINAC DUMPY BRUGH
TORSE LINAC DUMPY BURGH
YEARS TONDI CLUMP BHANG
YEARS TONDI CLUMP BIGHT
YEARS TONDI CLUMP BOUGH
YEARS TONDI CLUMP BRUGH
YEARS TONDI CLUMP BURGH

Moving Stickies Data to a New Mac

I recently set up a new Mac (MacBook Air M1 2020 running Big Sur) for a friend and we decided not to use the Migration Assistant to copy the data from her old Mac. I manually copied over documents, photos, etc., but not any applications or Library contents. That all worked as expected, yielding a new, clean machine.

One thing that didn't come over was her vast collection of Stickies. Consulting the web, I found a number of pages that described mixed results copying over the ~/Library/StickiesDatabase file. As a test run, I tried doing that on a test Mac also running Big Sur and it worked. Then I tried it on her machine and it didn't work, instead of showing her zillions of notes, it showed just the default introduction notes. I believe that's because she ran Stickies, found her notes missing and contacted me whereas I had never run Stickies on my test Mac.

It seems the StickiesDatabase is perhaps an alternate rendering of some other authorative representation of the Stickies data. My guess is that the first time Stickies runs, it sees it doesn't have existing data, checks to see if there's a StickiesDatabase file, and copies any notes found there to the real database. On subsequent runs, it does not do this, so replacing the StickiesDatabase file does nothing. So, how to get her machine back to the first run state?

I went to the Terminal and searched for everything in the Library folder with Stickies in the name:

find ~/Library -name '*Stickies*' -print 2>>/dev/null
/Users/USER/Library/StickiesDatabase
/Users/USER/Library/Application Scripts/com.apple.Stickies
/Users/USER/Library/Application Scripts/com.apple.StickiesMigration
/Users/USER/Library/Scripts/Applications/Stickies
/Users/USER/Library/Containers/com.apple.Stickies
/Users/USER/Library/Containers/com.apple.Stickies/Data/Library/Preferences/com.apple.Stickies.plist
/Users/USER/Library/Containers/com.apple.Stickies/Data/Library/Stickies
/Users/USER/Library/Containers/com.apple.Stickies/Data/Library/Stickies/.SavedStickiesState
/Users/USER/Library/Containers/com.apple.Stickies/Data/Library/Application Scripts/com.apple.Stickies
/Users/USER/Library/Containers/com.apple.StickiesMigration
/Users/USER/Library/Containers/com.apple.StickiesMigration/Data/Library/Application Scripts/com.apple.StickiesMigration
/Users/USER/Library/Caches/com.apple.helpd/Generated/com.apple.Stickies.help*10.2

The stuff in the Containers folder looks like where the Stickies app might be storing the authoritative data, so I backed up the current contents then deleted the com.apple.Stickies and com.apple.StickiesMigration folders. With the StickiesDatabase file from the older Mac (running Mojave), we ran Stickies and it brought in all of the old Stickies. They were all stacked up in the same location, so it looked like only one note, but by moving the top note, it revealed the next note and so on.

Your mileage may vary, depending on the source and destination version of macOS. Maybe it would be better to copy over the com.apple.Stickies and com.apple.StickiesMigration folders instead of just deleting them.

Also, maybe consider using something better than the Stickies app for storing notes. I like Growly Notes, it's awesome, free and doesn't hide your data in the Library, making it easier to manually migrate to a new Mac.

Update Febrary 13, 2021

Derrick Alderman notes that to get into your user Library folder, go to the Finder, hold down the option key while clicking on the Go menu, and choose Library. That's less nerdy that using the Terminal app. He notes he had success manually recovering his stickies from a Catalina Time Machine drive to a new Big Sur installation by moving the contents of [Home]/Library/Containers/Stickies/Data/Library/Stickies (a number of .rtfd files), from the Time Machine backup to the same location on the new computer.

2018 Nissan LEAF Test Drive

At the National Drive Electric Week event in Seattle, Cathy and I saw the newly-announced but not yet available 2018 Nissan LEAF. At that event, we signed up for a test drive.

ndew-seattle.jpgToday, October 23, 2017, Jose pulled up in front of our house in a beautiful blue Nissan LEAF for our test drive. We spent about an hour going over the vehicle and then out for a drive. Jose was enthusiastic and very knowledgeable about the car. We have a 2011 LEAF, so I'm familiar with that but haven't driven any of the newer LEAFs, so that's my perspective.

blue-2018-leaf.jpgBack Seat

The LEAF claims to be a 5-passenger vehicle, but the middle back seat has no head rest, so no neck protection in a rear-end collision. We often have 5 adults in the car, so that matters to us. I've been especially aware of this since we were rear-ended this summer. Fortunately, it was just the two of us in the car at the time, and neither of us were injured. My head hit the head rest pretty hard, so I'm glad it was there. I can't understand why Nissan doesn't protect the middle seat passenger.

back-seat.jpgCharge Cord

The SV and SL packages include a dual Level 1 (120V)/Level 2 (240V) charge cord. The standard 120V plug comes off to reveal a NEMA 14-50 240V plug.

charge-cord.jpgWith so much public charging available now, there's not much need for Level 2 charging away from home, but the dual mode cord means an owner can upgrade their home charging to 240V by just installing a NEMA 15-40 outlet.

Quiet Ride

When we started the test drive, right away I noticed how quiet it is. I'm told it has the same pedestrian warning sound as the 2011 model, but I couldn't hear it or the inverter whine which are pretty apparent in the 2011. I used to think our LEAF was quiet, but the 2018 is amazingly quiet. There was just the barest hint of a sound at low speeds in the driveway, maybe the pedestrian warning or the electronics, but much quieter. Likewise for road noise at freeway speeds, much quieter than our old LEAF.

One Pedal Driving

One of the best things about the electric driving experience is one pedal driving. It's so natural: push the accelerator pedal to go faster, let up to go slower. With regenerative braking, an EV can be much smoother and natural than a gas car, can slow down on a steep hill without using the brakes, and cruise control can hold you at a steady speed up and down hills. Automakers seem to be afraid of taking full advantage of this feature for fear it will be unfamiliar to gas car drivers, but Nissan has fully embraced it in the new LEAF. In the 2018, I was able to bring the car to a full stop on the steepest part of our driveway. Amazing! At the bottom of our drive, I brought it to a full stop, nudged it forward to look around our mailbox for traffic, then eased onto the road, all using just the accelerator pedal.

Nissan calls this feature ePedal. It can be turned on and off, and can be set to on or off by default. So, gas car drivers can test drive the car without it, then turn it on when they are ready to try driving a car with a superior drivetrain. For most people, once you get used to one-pedal driving, you'll find a gas car feels outdated and you'll never want to go back.

Analog Speedometer

The 2018 LEAF drops the large, easy-to-read digital speedometer for a boring analog speedometer. Jose tells me that Nissan thinks people don't like the digital speedometer, that it doesn't provide feedback on acceleration the way an analog speedometer does. I like the digital speedometer and find that having my back pressed into the seat is all the feedback I need on acceleration.

speedometer.jpgProPilot

Nissan did a demo of autoparking at the worldwide announcement, but that feature is only available in Japan, not the United States. Jose gave me the lame company line that US drivers don't use the autoparking feature; maybe we'll get it later. I don't know what the real story is, but that's nonsense.

We got on the freeway and I engaged the ProPilot cruise control feature. As with any cruise control, you get to the speed you want then hit a button. The car will keep you at that speed when it can, but responds to traffic and slows down when there's a slower car in front of you, then speeds back up when the road is clear. It also detects the lane lines on the road and keeps the car centered in the lane. Despite being a nice, sunny afternoon with clearly visible lines on the freeway, the car lost the vision lock a few times and I had to take control. It did slow down when a slower car got in front of us.

It seemed to me like the car was keeping us to the left of center in the lane. Maybe its sensors are better than mine, but I found it a little unnerving when we had a giant semi slowly pass us on the left. I didn't like being so close and took control to put us more center-right in the lane.

When we exited the freeway, I left the ProPilot cruise control on which arguably isn't how it's intended to be used. The exit peels off very gradually for a pretty long, straight stretch. That was working fine, the ProPilot was slowing down to match the car in front of us. As the lane made a gradual curve to the right, the car in front of us was no longer directly ahead, so the LEAF tried to resume full speed. It clearly didn't understand that the lane was curving and that slow car was still in front of us. I disabled the ProPilot at that point.

Maybe it would be cool on a long freeway run, but I found the ProPilot to be too unreliable to really relax and let it drive.

Even when the ProPilot isn't engaged, it watches the road and warns you if you drift in the lane. That happened twice to me, once when I was a little off center and again when the road was curving and I thought I was in the right place.

All-Around Camera

When we got back to the house, I tried out the all-around camera (SL package only). When you pop the LEAF into reverse, the center console screen shows both the backup camera and a simulated overhead view that displays the car's full surroundings. I know the LEAF has had a feature like this available for a few years, but it was super cool to see it in action. It was just like there was a camera over the car looking down to show the car's position in the driveway. It's done with four side camera and math, a very nice effect.

rear-camera.jpgBluetooth Audio

I paired my iPhone 6 up to the car to play some music. That works great, with plenty of volume. The Tesla Model S fails the "enough volume" test when playing Bluetooth from an iPhone. So that was nice.

Premium Bose Sound System

The test drive vehicle was a top-of-the-line SL with all the bells and whistles, including a super-duper Bose sound system which eats up a small slice of the hatch with amplifiers. When I had my iPhone hooked up, I played some Led Zeppelin and found the sound underwhelming. Our Tesla Roadster has a good sound system, with an Alpine headunit we installed. Those Zeppelin tunes sound great there, one of the pleasures of driving the Roadster. Not so much in the LEAF.

trunk-cord-bose.jpg

Heated Seats

We put in a very early order for our 2011, but then postponed it until they came out with the cold weather package late in the 2011 model year. Heated seats are a big win in an electric vehicle because they are more energy efficient than cabin heating, and the heated steering wheel is a guilty pleasure we love. The 2018 offers heated seats and steering wheel with the all-weather package, but it doesn't heat the rear seats. We use our LEAF in the winter and don't want to leave our rear-seat passengers in the cold. With the bigger battery, using the less efficient cabin heater is less of an issue, but we like offering heated seats to our rear-seat passengers.

Summary

Overall, the 2018 is a huge upgrade from our 2011. Not only the increased range from 84 miles to 150 miles (EPA rated range), but amazing one-pedal driving, nicely improved sound insulation and plenty of cool tech available in the higher package levels. Unfortunately, the lack of a fifth headrest makes us less interested in upgrading to a new LEAF.

OVMS and the Tesla Roadster Charge Time Predictor

Updated April 14, 2014 to add section on charging efficiency.

Charging an electric vehicle is pretty easy: just like my cell phone, I plug it in when I get home and it's fully charged in the morning. It doesn't matter how long it takes because I'm not waiting for it to finish; the car just charges up and waits for me.

That's pretty much the whole story for local driving, but I like driving electric so much I prefer to do longer trips electrically rather than burning gas. On those longer trips, it can be helpful to know how long a charge will take. To help figure out charge times in our Roadster, I did a study in 2010 on how charge rates and energy efficiency vary with available power and published a blog with the results. That blog has a table that shows charge rates for various charge rates from 120V/12A up to 240V/70A.

Charge Rate Ideal Miles
per Hour
Current Tapering Begins At:
Std % Std IM Range % Range IM
120V - 12A 3.3
120V - 16A 5.1
240V - 16A 13 93 179 82 205
240V - 24A 20 94 180 82 205
240V - 32A 28 93 178 82 207
240V - 40A 36 93 178 81 204
240V - 48A 42 91 174 80 201
240V - 70A 61 84 161 75 188

That charge rate table is handy, but it has some limitations:

  • It's a pain to load up the web page and do the math.
  • It covers the full range of charging options from the lowest to highest power rates, but it doesn't cover every possible rate, e.g. lots of sites are on 208V circuits instead of 240V.
  • It's specific to our car and the moderate temperatures in our garage.

The situation also gets more complex as the charge gets near the top and the car starts tapering the charge rate to pamper the battery pack, so calculating the charge time to full is more complicated than just looking at the available power. The graph below from the original study shows how the charge rate tapers down from various power levels.

Tesla_Amps_vs_SOC.png
Finally, since the Roadster has an active thermal management system that cools (or heats) the pack to keep the battery temperature in the best range, and that system uses power, the charge rate also depends on temperature, something my original study didn't address at all.

To build a more complete charge time predictor, I'd need to get charge data across a wide range of power levels and ambient temperatures, develop a charge tapering profile to use for calculating time-to-full, and I'd need to do this for each of the Roadster's three charging modes. This would require capturing a giant amount of charge data, which would need to come from Roadsters in different climates since the temperature in our Pacific Northwest garage doesn't vary much.

Open Vehicle Monitoring System

The Open Vehicle Monitoring System (OVMS) is an open source hardware and software project created by Mark Webb-Johnson, based in part on earlier work done by Scott Swazey who created the Tesla Tattler. OVMS consists of a $130 device that plugs into the car to both collect information and send commands. The device can interact with the driver via SMS messages and/or relay through a web server which communicates with smartphone apps. Since initial deployment on the Roadster, OVMS has been expanded to support other vehicles, all through volunteer support from vehicle owners.

Because the device sends data to a server and that data is stored (for a limited time period), there was a vast amount of charge data accumulated ready to be studied. Mark was kind enough to get me an anonymized capture of that data, 179 MB of data from 126 devices. The data is stripped of all identifying information, so I can't tell anything about the car or owner: no location or even VIN number. I can't tell if a given car is an early Roadster 1.5 in southern California, or a late 2.5 in Norway. What I get is records about every 10 minutes while the car is charging that tells me the time, SOC %, ideal miles, charge mode, charge voltage and amperage, various temperature readings, and the odometer.

Analyzing Charge Rates

I was able to extract data on just over 7,000 usable charging sessions. The graph below shows the available kW vs. temperature for each session. If you don't speak Celsius, 0°C is 32°F and 40°C is 104°F. Temperatures that are much above 40°C are probably due to situations where the Roadster ambient temperature sensor is sitting in direct sunlight on a hot day.

kW-v-temp.jpg
You can see clusters around common charge rates. The two lowest groups are at 1.44 kW (120V/12A) and 1.92 kW (120V/16A), and there are big groups around 7 kW (240V/30A) and 9.6 kW (240V/40A).

I wrote code to march through the data, identify records that correspond to each charge session, calculate the charge rate for the portion of each charge where the car is drawing the maximum allowed current for a steady power level, and note where tapering begins. I then sliced the data to see how temperature affects the charge rate at a given charge level. For example, the graph below shows the steady power charge rate (in ideal miles per kWh) vs. the average ambient temperature sensor reading for all of the charge sessions between 6.8 and 7.2 kW.

charge-rate-7kwh.jpg
The data shows a slight downward trend in charge rate with increasing temperature, which is reflected by the downward slope of the best-fit straight line approximation to the data. There is, however, a lot of variation in the data. Other factors (battery temperature, enclosed or open-air charging, battery pack starting temperature, etc.) have more effect on the charge rate than what can be predicted by knowing the average ambient temperature sensor reading during the charge, so the model can't predict differences in charge times from those external factors.

Using this data slicing, I was able to build a model that predicts the steady-state charging rate for power levels from 1.4 to 16.8 kW. The model incorporates a reasonable data set from a little below freezing to 40° C (104° F). Beyond that temperature range, there's isn't a lot of supporting data, so the model doesn't cover cases where battery heating is required or where battery cooling is extreme.

Modeling Charge Tapering

To figure out tapering curves, I looked at the onset of tapering for each charge mode. Below is the graph of the standard mode data showing the ideal miles at which tapering begins by charge rate.

Std-Mode-Taper-Onset.jpg
Once again, you can see that there's a pretty clear trend, reflected by the best-fit straight line, but there's also a lot of variation. Part of the variation is because different cars have different capacities in their battery packs. A nominal new pack will charge up to about 192 ideal miles in Standard mode, but a more well-traveled pack might only charge up to 170 ideal miles. Those two packs will taper the charge rate differently. To build the tapering profile, I had to allow for differences in the capacity of the cars in the data set and adjust accordingly.

The Charge Time Predictor

Doing this fairly giant amount of data analysis, I was able to build a charge time predictor function that is now incorporated in both OVMS and the Tesla Tattler. As you can see from the variation in the vehicle charging data, it's impossible to be perfect for every car, but the charge time predictor generally hits the mark within 30 minutes or 10% of the charge time. It doesn't do as well in temperatures below freezing or much above 100°F, or when the car is charging in a small, enclosed garage, or if the ambient temperature sensor doesn't reflect the actual air temperature, etc., but for common conditions, it seems to be doing a pretty good job.

In addition to the general variation in the data, there's another issue that affects charge times. Occasionally, the Roadster will charge up to the expected charge level (ideal miles) in about the time I expect, but then keeps going. For example, our Roadster generally charges to about 180 ideal miles in Standard mode, but sometimes it will hit 180 and just keep going, perhaps taking another 30 or 40 minutes to finish, showing a charge level that's wildly implausible, like over 190 ideal miles. Ten minutes after the charge, when the car recomputes the actual energy in the battery based on post-charging data, the charge level will drop back to the expected level. So these exceptionally long charge sessions don't seem to actually put any extra energy into the pack, despite the end-of-charge reading. I suspect the car is leveling the individual brick charge levels. When this happens and makes the charge run late, if I need to leave, I just interrupt the charge and go.

Good for the Driver, the Car, and the Utility

Having a charge time predictor enables a whole new charging feature: the ability to set the end time for a charge. This is important for two reasons.

First, when I'm doing a full range mode charge prior to a long drive, I'd really like the charge to finish shortly before I'm ready to leave. When charged to full, the Roadster runs the coolant pump to keep the battery temperature cool and equalized, which drains power. I'd rather be driving on those electrons for both the added range and energy efficiency.

Second, it's nice for the utility. Since we first got the Roadster, we've used the built-in charge timer to delay charging until off-peak hours. Our utility doesn't have time-of-use (TOU) rates, so we don't get any financial benefit, but it's still the right thing to do. Unfortunately, this creates a problem as we get more EVs on the road. If everyone sets their car to charge at some even hour, like midnight, that creates a surge for the utility. In areas where TOU rates are in effect, you can see this effect in the data collected by the EV Project. Using the charge time predictor with the new OVMS "charge by" feature, I can set the charge to end around a specific time, so the start time varies with how much energy I use driving each day. Since the actual charge time varies from the predicted time, even the end time varies, so there won't be a big instant spike or drop at either end of the charge for vehicles that set a charge end timer. That's good for the grid.

Charging Efficiency

Although not directly related to charge time prediction, the data set also allows for examining how charge rate effects efficiency. Using the model developed for the charge time predictor, the graph below shows how charging efficiency varies with charge rate. Charging efficiency is expressed as Wh per ideal mile, so smaller numbers are better.

Wh-per-IM.png
This shows that in moderate temperatures, charging efficiency increases with charge rate. There's a huge improvement between 120V/15A (1.44 kW) and 240V/24A (7.68 kW), but after that there's a much more gradual improvement with increasing charge rates.

Availability

The charge time predictor for the Tesla Roadster is available in the latest firmware versions of OVMS and the Tesla Tattler and also on the Tesla Roadster Charge Time Predictor page.

The Hybrid Garage

Electric vehicles are awesome for local driving. Driving within the single-charge range of an electric vehicle is more fun, more convenient, and cheaper than driving a gas car. Many people are drawn to the idea that they can abandon gas stations, fuel at home, drive 130 miles for the cost of a gallon of gas and all in a car that has a quiet ride and instant, smooth acceleration that can't be matched by a gas car.

However, electric cars are not great for driving long distances beyond their single-charge range. Make no mistake, electric road trips can be done. Plenty of EV owners love driving electric so much they are willing to trade off some convenience for the rewards of driving without combustion, but that's a choice. People who haven't previously owned an EV aren't going to sign up for that when they buy their first.

The Plug In Hybrid

The solution to this that first comes to mind for many people is a plug-in hybrid vehicle. The Chevy Volt is an electric vehicle that has a gas engine that can be used to extend the range of the car, both by augmenting the electric motor and charging the battery. Especially for single car households, the Volt can be an excellent solution: drive electric for your daily commute and burn gas for longer trips. The trade off is that the Volt is more expensive than an all-electric Nissan Leaf, has less than half the electric range, and still needs regular maintenance like oil changes.

No Car Does Everything Well

The issue of a diversity of demands from a single vehicle is not a problem that's unique to electric cars. No car is great for every purpose. You can't carry more than two people or tow a boat with a Miata. A 15 mpg pickup truck is pretty silly as a single-occupant urban commuter vehicle.

Households that own more than one vehicle have the opportunity to own different types of vehicles which excel at different tasks. A household might own a small, economical sedan for daily driving and a more rugged vehicle for excursions into the wilderness.

The Hybrid Garage

Some 60% of Americans have a garage and multiple cars and 78% drive less than 40 miles per day. The tens of millions of American, and many more worldwide, who are in both groups are perfect candidates for what I call the "hybrid garage."

The hybrid garage is replacing one of your gas cars with an all-electric car, keeping a gas car that's good for the things the EV doesn't do well. There are several potential advantages to the hybrid garage over owning a plug-in hybrid car: you get more electric range for the car's purchase price, you don't have to do oil changes on the electric car, and you don't have to worry about gas going bad because it just sits in the tank for months.

Even a single-car household can adopt the hybrid garage approach. Depending on how often a longer-range vehicle is needed, renting a car occasionally may be a lot cheaper than owning a second car. Swapping cars with a friend or relative can take care of the occasional road trip, and allow someone else to see first hand how convenient driving electric is.

Who Gets to Drive the EV?

There is a downside to the hybrid garage: once you have an electric car in the garage and people find out how nice it is to drive electric, everyone will want to drive that car. Fortunately there's an easy solution that Cathy and I developed after we bought our first electric car: whoever is driving farther gets the electric car. This also turns out to be the cure for range anxiety. When you realize how much of your driving can be done with a car that has a "limited range" you'll stop worrying about running out of juice and wonder how it is that we got so used to tolerating the inconvenience of driving on gasoline.

Quiet Vehicles and Pedestrians

I've been driving electric vehicles since 2008, logging over 50,000 miles, and have never had an experience where my vehicle's lack of engine noise created an unsafe situation. However, the issue of quiet vehicles and pedestrians is subtle and complex.

I have had a pedestrian walk backwards through the traffic lane in a parking lot while carrying on a conversation with someone across the lot. She didn't notice my vehicle, but I was watching where I was driving and going slow enough to react to her carelessness. I just stopped and waited about 30 seconds for her to see me. She of course made a rude comment blaming me for the unsafe situation she caused.

I've also had many times when driving through a parking garage where pedestrians are walking up the middle of the traffic lane, totally oblivious to my presence. However I find that happens with about the same frequency it did when I was driving gas cars, which I attribute to the echoing in concrete garages making it hard to hear slow-moving vehicles from behind, even when they are close.

I've also had the experience of being in a shopping center parking lot, hearing a car drive up behind me, and before turning around knowing it was my wife, Cathy, because I recognized the distinctive sound of a Tesla Roadster. On the flip side, Cathy has noticed not being able to hear a nearby gas car in a parking lot because of the noise made by a much louder gas car an aisle or two over.

As a responsible driver, I don't depend on pedestrians hearing the roar of my engine so they can scramble out of my way before I mow them over. But the situation is more complex than just my personal experience.

In May of 2011, I participated in a meeting of the United Nations working group that is developing a proposal for an international standard for quiet vehicles. There I learned a great deal about the subject and was able to share my insights as an experienced electric vehicle driver.

The predominant sound made by cars moving above 15 to 20 miles per hour is tire noise. At slower speeds, it's engine idling, fans, and so forth. It's those lower speeds that are of concern.

Hybrid and electric vehicles aren't the only quiet vehicles on the road. Many modern sedans are also virtually silent at low speeds where tire noise is not significant. Therefore, the UN is taking a broader approach to this problem than the US Pedestrian Safety Enhancement Act of 2010, which only considers minimum noise levels for electric and hybrid vehicles.

The sound made by gas cars is actually quite poor for alerting pedestrians to nearby vehicle traffic. Most of the sound made by internal combustion vehicles is low-frequency, which humans have difficulty locating, and carries for long distances, adding to ambient noise levels that can mask out nearby vehicles.

For an artificial car sound to be effective, it has to be localizable and distinguishable as coming from a vehicle. So having an EV rumble like a muscle car or chirp like a bird is a terrible idea. Studies presented at the UN workgroup meeting show that the best sounds are broad spectrum sounds without low frequency content.

The issue is even more complex for blind pedestrians who develop skills in using their senses in ways that are completely outside the experience of the sighted public. The idling sounds made by stationary vehicles are useful not only for detecting the presence of nearby cars, but also for using them as positional markers. Consider walking across a wide, busy street and trying to stay in the crosswalk with your eyes closed. The sound of the idling cars nearest the crosswalk act as navigational beacons, keeping blind pedestrians from drifting out of the crosswalk and into traffic. For this reason, it's important to be able to hear a car in the street even if it is not moving.

It's also important to be able to judge the size of vehicles by their sound. Drivers behind a large, stopped vehicle can get impatient at the hold-up and decide to blast around the unwanted obstruction, only to find that there was a good reason for the large vehicle to be stopped: pedestrians in a crosswalk. For this reason, blind pedestrians may choose to avoid this risk by choosing not to cross when they hear a large vehicle at the head of the line.

As an EV driver, I appreciate the quiet ride of electric cars. The last thing I want is some obnoxious artificial sound added to my car. From what I learned at the working group meeting, a properly designed sound doesn't have to be overly loud, it can be effective even at a sound level that is below the ambient noise level. I believe we can add sound to quiet cars to increase pedestrian safety without compromising the advantage of electric cars in improved driving experience and reduced noise pollution, but doing so demands careful thought and consideration of many complex issues.

Quick Chargers: Ignore The Charge Percent!

Electric vehicle drivers are excited to see the first DC Quick Charge stations coming online. Oregon and Washington have done their part to power up the West Coast Electric Highway allowing electric vehicle drivers to travel I-5 from the Canadian border to the Oregon-California border and take advantage of stations that can charge a Nissan LEAF or Mitsubishi iMiEV from empty to 80% in about half an hour. This greatly increases the usable range of electric vehicles for longer trips and also provides a safety net for rare situations when drivers unexpectedly need more than their normal overnight charge.

Unfortunately, there's a problem that is causing a lot of confusion that can result in a driver getting less charge than needed. Even though the stations are working properly, drivers may think something went wrong because of a user interface issue.

AV-DCQC-Screen.pngThe above is the screen from an AeroVironment DC Quick Charge station in Tumwater, WA, as shown while charging our Nissan LEAF in June. The screen shows the driver two pieces of information: the amount of energy delivered to the car and a charge percent.

The problem is the displayed charge percent: it is not the car's state of charge (SOC) and should not be treated as such by a driver to decide when to end the charge.

It's pretty well known that it's difficult to determine the exact SOC of a car's battery. Even the best estimate of the battery's SOC may be off by a few percent. That's not what's going on here. The SOC value reported to the station is completely artificial and differs significantly from the car's estimate of the true SOC.

In addition to showing the invalid SOC value to the driver, Blink quick charge stations also require the user to choose a station-controlled charge limit. This has two big problems. First, the LEAF wants to control the charge and will stop the charge at either 80% or near 100% based on the battery state at the start of the charge, so even if you choose 100% on the station the LEAF will terminate the charge at 80% if the car was at 50% or less when the charge started. Second, the Blink station doesn't know the real state of charge and therefore cannot know when to stop charging at the point it says it will.

Here's an example. I recently used the Blink quick charge station at Harvard Market in Seattle, WA. I arrived with just over a half charge remaining, which means the LEAF will allow me to do a full quick charge up to near full capacity. After plugging in the car, the screen on the Blink station gave me a choice of charge levels, defaulting to 80%, which was the highest level shown. I had to press a "more options" button to be able to choose a 100% charge. The graph below shows data collected from the resulting 52-minute charge, comparing the car's actual SOC with the SOC shown on the station's screen.

Blink_50_to_100_Graph.pngAs you can see, not only is the reported SOC higher than the actual SOC, the reported SOC rises more quickly, increasing the gap as the charge progresses. Throughout the entire charge, the SOC shown on the station consistently overstates the actual charge level and the problem gets worse later in the charge period. As the car gets to about 80% actual SOC, the reported SOC jumps up to plateau near 100% and just sits there for the remainder of the charge, even though the car is far from fully charged.

Had I left the default 80% setting, the charge would have stopped when the reported SOC hit 80%, but the car was really only at 73% at that time. A requested 90% charge would have stopped around 80% actual.

Any driver who sees this behavior and doesn't know that the charge percent value on the station is not the SOC would see it jump up to 97%, perhaps watch it sit there for a few minutes, and likely decide that it would be a waste of time to spend any longer waiting for that last 3%. If the driver ends the charge at that point, the car will be missing perhaps 10% of the potential charge. If that last 10% is needed to finish the journey, this could result in a very unhappy EV driver.

It's not clear where this value comes from, but displaying this invalid SOC on the quick charge stations has created user interface problem with unfortunate consequences for LEAF owners, and perhaps iMiEV owners as well.

So to any EV driver using a CHAdeMO quick charge station that shows an SOC percentage:

1. Ignore what the station shows. Put a sticky over it if you have to. Only look at the car's representation of the SOC.

2. If the station offers you different charge levels, choose 100% charge so that you get the car's best available charge level. If you want to stop the charge early for some reason, do it based on the SOC shown by the car.

I'll contact the quick charge station manufacturers to make sure they are aware of this problem. In the meantime, please help spread the word so EV drivers can get the maximum benefit from these highly valued stations.

For charts of two AeroVironment quick charge sessions, see Cathy Saxton's report. More tips for using quick charge stations are available on our Avoiding Quick Charging Pitfalls page.

US 2 DCQC Inaugural EV Rally

On Saturday, June 16, 2012, a dozen electric vehicles made the inaugural drive along US Highway 2 over the 4,061-foot summit at Stevens Pass utilizing the newly-installed quick charge stations. Most of these vehicles recorded data for driving and charging; this blog is a summary and analysis of that data.

Cars charging at the DCQC and Level 2 stations in Skykomish, WA.

US2qc-skykomish.jpg

We have analyzed this data as well as measurements from other driving and have created pages with information on planning an EV road trip, including guidelines for predicting energy use based on drive conditions and tips for avoiding quick charging pitfalls.

Thanks to Ron Johnston-Rodriguez for all his work getting electric vehicle charging stations installed along US 2 and organizing this event.

Route

This event marked the official opening of DC quick charge (DCQC) stations in Sultan, Skykomish, Leavenworth, and Wenatchee, WA. It was also a test of the spacing between stations. Tom had helped with the US 2 electrification process by collecting data for driving this route in our Tesla Roadster in December, 2010, so we had good information on the energy use required for each segment.

With a carefully-orchestrated schedule from Ron, each vehicle was assigned a charging period at each station. This added a unique constraint, as vehicles would not necessarily have sufficient time for a full charge at the DCQC stations. We provided suggestions for a target charge level when departing each location and the expected energy required to comfortably reach the next station. The most demanding segment was the one over Stevens Pass; our guidance included a recommended state-of-charge level at the summit so drivers would know whether they should stop for Level 2 charging at Stevens Pass ski resort.

We got nifty SWAG from Leavenworth and Wenatchee!

US2qc-goodies.jpg

Cars

We have data from 8 Nissan LEAFs, 1 Mitsubishi iMiEV, and 1 Tesla Roadster.

The DCQC spacing worked great for the LEAFs.

The iMiEV was able to make the drive with additional charging for the segment over the pass (charging Level 2 at Stevens Pass in both directions and Level 1 at Nason Creek for the westbound trip).

The Roadster can't use DCQC stations, but with its longer range didn't need much extra energy use. Tom was able to "opportunity charge" at Level 2 while we charged our LEAF and participated in the ribbon-cutting ceremonies.

Data

For those interested in all the gory details, the data and analysis are in this spreadsheet (XLS, 214k).

Drivers recorded information on time, distance, energy, temperature, and driving conditions. The details are in the individual EV# sheets. There are summary sheets for driving and charging that compare the data for multiple vehicles.

The iMiEV (EV1 in the spreadsheet) used an amount of energy similar to the LEAFs.

There were three LEAFs with after-market state-of-charge (SOC) meters that enable more precise monitoring of battery state than the factory instrumentation. These meters show the SOC as a percentage, and also in a unit called a "gid," which represents 80 Wh of energy in the battery. The gid values fell nicely in the range of values based on the LEAF's more coarse SOC bars.

We drove our LEAF (EV4) and Roadster (EV4b) together so that we could compare energy use for the same driving conditions. They turned out to be very similar; there is a summary sheet showing the data for both cars together.

Thanks to everyone who collected and shared data: Patrick, Phil, Lee, Jeff & Mary Lynne, Matt & Laura, Bruce, George, and Mike & Kimm.

EV drivers at the US2 DCQC inaugural ceremony in Wenatchee, WA.

US2qc-wenatchee.jpg

Photo by Jessie Lin, WSDOT. Used by permission.

Quick Charging

DCQC stations made it practical to make this trip (and the return) in a single day. We learned several things about the stations with all the data collected by drivers during this event.

One of the most enlightening was confirmation of an observation during our prior DCQC experience: the station-reported SOC is not a useful indication of the car's charge.

When using a DCQC from under 50% to get to 80%, the LEAF's charge rate averaged 400-500 Wh/minute. When charging from over 50% to "full," the charge rate averaged about 200 Wh/minute.

The charging overhead (energy from the station that didn't make it into the battery) was 10-18%.

More details on DCQC are on our page with tips for avoiding quick charging pitfalls.

Driving

For each drive segment, these are the minimum and maximum kWh (and corresponding gids and bars) used between the DCQC stations. The energy use will vary based on speed and weather conditions.

Trip miles kWh gids bars
Eastbound
Sultan to Skykomish 26.4 7.20 - 8.24 90 - 103 4.5 - 5.2
Skykomish to Leavenworth 51.0 12.24 - 14.88 153 - 186 7.7 - 9.3
Leavenworth to Wenatchee 20.5 2.40 - 2.48 30 - 31 1.5 - 1.6
Westbound
Wenatchee to Leavenworth 22.3 5.60 - 5.84 70 - 73 3.5 - 3.7
Leavenworth to Skykomish 51.0 12.48 - 13.60 156 - 170 7.8 - 8.5
Skykomish to Sultan 26.5 4.80 - 7.04 60 - 88 3.0 - 4.4

Conclusions

The spacing of the DCQC stations along US 2 over Stevens Pass works well for LEAF drivers. Level 2 charging at the pass is either helpful or mandatory for iMiEV drivers, depending on the driving conditions.

We believe that an SOC meter is a valuable tool when making a trip like this, especially when pushing the range limits of the car. Because we'd projected our energy use for each segment and had a meter providing a higher resolution SOC reading, we were able to minimize the amount of time that we spent charging — including successfully skipping one station — and return home with a comfortable buffer.

1,823-Mile Oregon Coast Tesla Road Trip

oregon-coast.jpg

roadtrip-route-thin.jpgCathy and I took an 1,823-mile electric vehicle road trip to attend the Plug In America board meeting in Berkeley, CA, on June 23rd, 2012. Ever since we took delivery of our Tesla Roadster in June of 2009, I've wanted to take it on a long road trip just to have the experience. Over the past three years, the challenge of making the drive from Seattle to California has been greatly reduced. When Rich Kaethler took delivery of his Roadster in San Carlos, CA, and drove it back to Seattle in August of 2009, and Chad Schwitters made his long trek from Seattle to San Diego and back in April of 2010, these were pioneering efforts. Now we have full speed (240V/70A) Tesla charging along I-5 from British Columbia to southern California, which makes it possible to do the Seattle-to-San Francisco drive electrically in just a couple of days.

However, Cathy and I wanted to take a more leisurely approach and add some new territory to the EV road trip experience, so we made our way down the Oregon and California coast on highway 101, eschewing the more convenient charging established on I-5. Here's what we did, what we learned, and a few adventures we had along the way.

Our Tesla Roadster has a range of about 240 miles at 55 to 60 mph on level freeway in moderate weather. In practical terms, that means we can generally drive 180 to 200 miles without any need to charge in the middle. About four hours of driving per day is our threshold for convenient travel and leaves plenty of time to enjoy a leisurely drive and see the sights, which works well with the Roadster's single charge range.

The coastal drive is a bit of a challenge because there is almost no installed public charging infrastructure. Fortunately, all we need is a power source, and one of the best sources for power is the 240V/50A service commonly available at RV parks. Finding charging is actually pretty easy; the challenge is finding a place to charge and a place to sleep nearby. Cathy did careful planning in advance, finding hotels and motels that either provided charging or were adjacent to EV-friendly RV parks.

Day 1 Because we had a four-hour delay from our intended start time, we cheated and took the easy route south down I-5 toward Portland, taking advantage of 70A charging while eating lunch at Burgerville in Centralia. That gave us enough juice to remove any chance of range concern for our 237-mile drive.

For our first night, Cathy found what turned out to be a wonderful location, the Harborview Inn and RV Park in Garibaldi, OR. The Inn is a modest little motel, but it and the RV park are right on the harbor, which was hard to appreciate when we arrived shortly after sunset, but treated us to a beautiful view as fog was lifting from the harbor when we woke up in the morning.

harborview-rv.jpg
The restaurant options in Garibaldi were pretty limited, so we got dinner in Seaside on the way, then ate breakfast in a dodgy little place in Bay City.


Day 2 We made a couple of stops in Lincoln City where there are two locations with two ChargePoint charging stations each. We didn't find much to do near either location, and we didn't really need to charge, so we took off after a quick bit of exploring. 

Cathy found some information online about the many wonderful historic bridges along the Oregon coast, so we made that our theme for the drive. One of our favorites was Cape Creek Bridge.

cape-creek-bridge.jpg
That night we charged at Charleston Marina RV Park in Charleston, OR. It cost us $23 to use an RV spot to charge overnight, but the folks were very nice and the manager expressed interest in installing EV charging stations. It was fortunate that we had a suite with a full kitchen at Charleston Harbor Inn, because there was very little in the way of restaurants open at the late hour of 5 pm on a Tuesday night. We bought some food at the local convenience store and made dinner.

Day 3 We took in the last of the Oregon coast historic bridges then crossed over into California with a quick stop at the Redwood National Park visitor information center in Crescent City. We stopped for a walk in the forest and a drive up to an overlook of the mouth of the Klamath River to watch gray whales feeding. Late that afternoon, we rolled into the Chinook RV Resort in Klamath, CA. They had all brand new 50A service in nice pretty enclosures that have a bar running right below the outlet, which prevented us from plugging in. The very helpful handyman was able to "modify" the enclosure on spot #2 so that we could plug in.

chinook-rv.jpg
Restaurant options in Klamath are very limited. One place had a big sign out front that said "Now Open" which, as we found out, isn't the same as "Open Now"; they seem to only be open from 11:00 am to 2:00 pm for "breakfast." Another place had people loitering out front and a sign that said "armed guard on duty." That didn't sound very inviting! Again, we had a suite with a kitchen at the RV park, but we didn't have groceries and the only store open in town is a gas station convenience store. We ate at Steelhead Lodge, which is not even a little bit vegetarian friendly. Cathy asked for a baked potato with cheese and was told "we don't have cheese." Definitely, another good place to make dinner in the suite; be sure to do your shopping in Crescent City.

Day 4 Was our most fun driving day, taking the Avenue of the Giants, a portion of the old Highway 101 running parallel to 101, to drive through the Redwoods. Driving a quiet electric car on a road surrounded by the forest canopy was one of my top 2 all time Roadster drives. We also had probably our best meal of the trip, lunch at the wonderful vegetarian Wildflower Cafe and Bakery in Arcata, CA.

We spent the night at the historic Benbow Inn in Garberville, CA. They feature biscuits and tea in the afternoon, an elegant dining room serving a seasonal menu, a rich event calendar (an outdoor jazz concert the night we were there), and free EV charging via a 50A outlet. There's also an associated RV park, which we planned to use until we learned about the hotel charging option. It was the priciest hotel we stayed at, but we just couldn't resist trying out a previously unknown EV-friendly hotel.

Day 5 We needed to drive 213 miles. Just to be safe, we stopped at what turned out to be two SemaCharge stations at Coddingtown Mall in Santa Rosa, CA. Although we'd heard reports that SemaCharge stations don't work with 2010 and later (v2.x) Tesla Roadsters, we were quite pleasantly surprised to find the one we tried worked flawlessly with our 2008 (v1.5) Roadster.

For our hotel in the Bay area, we chose the Four Points Sheraton in Emeryville because it was the closest EV-charging hotel to the Plug In America board meeting in Berkeley. (How can Berkeley not have a ton of public charging? What's up with that?)

Unfortunately, we weren't the only ones to figure out that this is the only charging station near Berkeley as we were unable to use the level 2 ChargePoint station until over 12 hours after our arrival. When we arrived, there was a Volt charging. While we were out for dinner, a Leaf pulled in and started charging from near empty. I happened to wake up way too early and could see the Leaf had finished, so I dashed down to start charging at 5:25 am. I didn't want to leave our very expensive adapter cable out all day, so I took a chance and unplugged when I left to take the bus to the board meeting. Fortunately, I was able to plug back in that evening, finish the charge that night, and top off again in the morning. When we left, a plug-in Prius was using the Level 1 station. When we got home, I checked the data from my Plug In America charging infrastructure study and found that station is one of the most-used ChargePoint stations in the country, averaging 11 hours of use per day.

four-points-sheraton.jpg
Neither the Leaf nor the Volt were driven by hotel guests, and the hotel staff was completely unconcerned that a guest was blocked from charging for over 12 hours. "Those stations are there for the public to use." That's all good, but we chose the hotel because of the charging station. Because of the high use rate, and no preference given to guests, I can't recommend this hotel for a single night stay where charging an EV is required.

Day 6 I attended the board meeting. Cathy visited the California Academy of Sciences at Golden Gate Park and had a quite an adventure with the bay area bus systems, but that could be a blog all on its own.

Day 7 There are a series of Tesla charging stations along I-5 making it possible to drive from the Bay Area to Seattle in two days. We wanted a more leisurely experience, so didn't need use any of them until we were almost home. Our first overnight was in Red Bluff, CA. We stayed at a Super 8 motel and charged across the street at the Rivers Edge RV Resort where we had another adventure. They claimed to have three 50A outlets, but we had to scrounge through the park to find them. We tried five that didn't have power until we finally found success with the sixth. The manager and the park handyman were very supportive and helpful. We ate a tasty late lunch at the New Thai House; the Yelp reviews weren't kidding that the food is spicy. We also took in a movie at the local cinema.

Day 8 In Red Bluff, the Tremont Cafe and Creamery is a decent place for breakfast, although we enjoyed the historical notes on the menu more than the missing-in-action service.

Although we only needed to drive 176 miles to Ashland, OR, we had to climb over the Siskiyous Mountains which means climbing to 4,000 feet, dropping back down to 2,000 then up again to 4,000. We could have done it on a single charge, but decided to try out a charging site in Redding, CA, while taking a walk through the adjacent Lema Ranch Trails.

Lema-Ranch.jpg
The Blink charging station was only delivering 187V (normally it's around either 208V or 240V), so we were only charging at about 75% of the rate we expected. This was fine for what we needed, but not so good if you're counting on a more typical Level 2 charging rate.

Historical note: while crossing the Siskiyous, we saw Tony Williams' Nissan Leaf speed by southbound, making the return trip from his BC2BC tour.

We arrived at the Chanticleer Inn in Ashland, OR, with plenty of charge remaining (25%) despite the serious elevation climbs along the way. Although there is a Level 2 station in Ashland, we arranged with Ellen at the B&B to charge from a 120V outlet. Since we were going to be there for 2 days, that was enough to get us charged (28.5 hours).

chanticleer-inn.jpg
Day 9 We were in town to watch three shows at the Oregon Shakespeare Festival, so we spent a second night in Ashland and had a great time. Ellen was very accommodating, both of our charging needs and our vegetarian diet. She even invited a friend over to see the Roadster which turned into an impromptu car show for our breakfast mates from the inn. It was a much more pleasant stay than at the hotel with the oversubscribed Level 2 charging station.

Day 10 We had a full charge and only a 60-mile drive, so we got to enjoy full-blast air conditioning on a hot day, driving up and down a couple of mountain passes in the left lane not sparing the accelerator pedal at all. I tried to show some restraint, but I have to admit it was more fun for me behind the wheel than for Cathy in the passenger seat.

We charged at the Level 2 AeroVironment station next to the DC Fast Charger while spending the night at the historic Wolf Creek Inn.

Day 11 Nearing the home stretch, we detoured to Corvallis, OR, to visit a friend from the EV community who generously allowed us to charge in his garage while we went out for lunch and had a wide ranging chat about EVs, wacky diets, and lots more.

In Portland, we met up with John Wayland and had dinner with John and his daughter Marissa at our favorite neighborhood Thai place in Portland, Thanh Thao. Sadly, the wonderful Jaciva's chocolate shop and dessert bakery had closed too early for us to visit.

We had another adventure in charging at the Downtown Crowne Plaza. They have two Blink stations, which we've used before without issue. That night, we started a charge at 10:27 pm and hit the sack. At 11:58, my cell phone woke us up with an alert that the charge session had ended abnormally. Concerned that someone might be messing with the car or the adapter cable, I dashed out to check. Nothing was disturbed, but something had terminated the charge session. I can't say for sure whether the Blink station burped, or someone messed with the locking switch on the Tesla connector (and put it back), but I was very pleased that I had an OVMS box (similar to the Tesla Tattler) installed and set to text me if a charge is interrupted. Without that notice, we would have found a partially charged car in the morning and then had to wait five hours before we could depart.

Day 12 We made our usual 30-minute stop at Burgerville in Centralia, WA, for a quick bit of charge and a meal. We totally dig Burgerville for their healthy fare, including vegetarian options, environmental consciousness, and especially for the Tesla charging station they have provided since 2010. From there, it was an easy drive home.

Planning a Road Trip Using DC Quick Charging

Hi, this is Cathy; I'm guest-blogging on Tom's page, and he's playing editor this time!

We recently needed to drive approximately 80 miles (one way) to get to clearer skies for viewing the Venus transit. That provided a great opportunity to try out DC quick charging (DCQC) with our LEAF.

We charged up to full in Bellevue using Level 2 charging, drove to the Tumwater DCQC station, charged back to full while we watched the transit, and returned home to Sammamish.

Data Collection

We have one of Gary Gidding's SOC Meters. It shows a state-of-charge (SOC) percent, which it calculates from a raw energy unit reported on the car's CAN bus. The meter can be set to show the raw energy unit, which the LEAF community has dubbed a "gid." It is reasonably well established that a gid represents 80 watt-hours (Wh). Gids are divided by 281 to approximate an SOC %.

Note that the pack kWh is not something that can be directly measured. The car determines this value through sophisticated measurements and calculations, which result in periodic adjustments that are seen as "jumps" in the gids.

Charging

We arrived in Tumwater with 2 bars, or more precisely 61 gids, which translates to 4.88 kWh, or 21.7%.

Since we were under 50%, our (first) DC quick charge brought us to 80%. The car charged for approximately 26:40 minutes, at which point it was showing 226 gids (18.08 kWh, 80.4%). The station reported having provided 14.36 kWh, and the car showed a net gain of 13.20 kWh.

The graph below shows the status each minute during charging. The lower blue bar shows the energy in the car's pack at the beginning of the time interval. The upper red bar shows how much energy was supplied by the station during the time interval. You can see that the total energy (existing + added) closely matches the pack kWh at the beginning of the next time period. (We only logged the station-reported kWh for some of this charge session.)

The SOC % axis is scaled to correspond to kWh values (both graphs).

DCQC-80.gif

It is interesting to note that the SOC % reported by the station (gold dots) does not match the SOC % of the car. We are not sure what causes this discrepancy, but we've seen this consistently in subsequent DCQC sessions.

We expected to need more than 80% charge to make it home, and we wanted to see how to handle getting a full charge after arriving at a station under 50%. So, after the first charging session stopped at the expected 80%, we unplugged and returned the connector to the station. Then we initiated another charging session.

Our second DCQC charge took 36:35 minutes, increasing the car's charge to 266 gids (21.28 kWh, 94.7%). The station supplied 3.609 kWh and the car's charge increased by 3.2 kWh.

DCQC-80-100.gif

At the end of the second charge, the battery temperature was registering 6 bars. Ambient temperature was 61° F.

Driving

trees.jpg

We have monitored gids and miles driven over several recent drives. For freeway and combined freeway / surface-street driving we see typical energy use in the range of 250 to 280 Wh/mi, with extreme readings as low as 230 or as high as 290.

The image on the left is after we had driven 74 miles from Tumwater to Issaquah. Stopping for dinner won out over completing the drive home and growing more trees.

Data from our drives to and from Tumwater:

milesWh / miNotes
65.9 251 Bellevue - Tumwater
79.1 235 Tumwater - Sammamish, slow freeway traffic for several miles

Details on a few legs of the trip from Bellevue to Tumwater.

milesWh / miNotes
23.6 247 Freeway, uneven speeds (traffic, merges, etc), partially rainy
15.7 255 Cruise at 60
7.1 259 Cruise at 60

Gids in Relation to Bars

GIDs.gif

The bars are based on an approximation of the percentage of the maximum available energy. This maximum varies with temperature as well as with battery age as capacity is reduced.

Therefore, there is not a static gid-to-bar mapping; it will vary based on current conditions. The image on the right shows gid readings that we observed as bars dropped during driving. It also shows a simple approximation of the gid values at the bar transition points. Since the gid values tend to vary a little anyway, those values should be an easy way to get a pretty close approximation to the actual kWh (gids × 0.08) remaining in the pack. (The gid range will be between approximately 20 × bars + 20 and 20 × bars + 40.)

Don't forget that there is some amount at the bottom (2%?) that is unavailable; the car will shut down before letting you deplete the battery that far.

When we got to approximately 50 gids, the LEAF warned us of low charge with the following:

  • Warning message ("Battery level is low") on the dot matrix liquid crystal display just above the steering wheel.
  • Illumination of the low battery charge warning light (the icon showing a pump with a plug).
  • Flashing driving range (affectionately known in the LEAF community as the Guess-O-Meter).

We arrived home with 35 gids remaining and did not see the turtle.