edatoakrun
Well-known member
="camasleaf"...The capacity will be less about 1% per 4F...
Is there any real documentation for that statement, either the amount of loss or consistent over a large temperature range?
I think this "rule of thumb" for battery capacity reduction with temperature may considerably overstate reduced capacity at lower battery temperatures.
It is very difficult to accurately measure battery temperature, and difficult to segregate the loss of capacity in a range test, from lower m/kWh due to colder driving conditions.
Last year (and in many range tests since, in the ~45 F to ~95 F range where I can tolerate driving without heater or AC use) I seem to have found capacity loss more like 1% per 8 F, than "1% per 4F", though my total range loss seems to come pretty close to that "1% per 4F" amount.
IMO, the most accurate way to determine capacity loss at lower ambient/battery temperatures would be for those monitoring recharge capacity to also note temperature as a factor:
https://docs.google.com/spreadsheet/ccc?key=0An7gtcYL2Oy0dG9vbzBiMW8tc1c2UzFKM3RiUG5ORHc#gid=0" onclick="window.open(this.href);return false;
edatoakrun
On 11/8/(11) I attempted to replicate the route and conditions of an earlier trip, which I had kept careful notes of, to try to see what sort of range reduction is caused by reduced m/kWh due to lower temperatures, and what proportion of this reduction is due to reduced battery capacity. I did this on a dry day with windows up, without using the heater or windshield wipers. I believe that I got about 5% reduction in battery capacity, and a slightly larger decrease in driving efficiency (m/kWh) resulting in a total range reduction of over 10%...
...This approximately 40 degree decrease in temp when charging, and 50 degree reduction when driving, resulted in about 10% recorded range reduction...
http://www.mynissanleaf.com/viewtopic.php?f=31&t=6701&start=60" onclick="window.open(this.href);return false;