DuncanCunningham said:
dhanson865 said:
If you live in a hot area spend effort avoiding letting it sit at 100% but don't avoid charging to 100% if you plan to drive it as soon as it is full.
What is classified as hot?
To me 80 degrees is hot because I'm from England. We live in Utah where the summers can get over the 100's during the days from July-August.
Check out http://www.electricvehiclewiki.com/Battery_Capacity_Loss" onclick="window.open(this.href);return false; specifically the parts about the "Battery Aging Model". You might say Hot are cities that have an aging factor higher than 1.0
You could also check out the real world capacity loss table* and see if a car lost bars in your state and use that as a proxy for how hot your environment is.
* http://www.electricvehiclewiki.com/Battery_Capacity_Loss#Real_World_Battery_Capacity_Losses" onclick="window.open(this.href);return false;
Battery Aging Model assumptions:
Both calendar capacity loss and cycling capacity loss are temperature dependent
Calendar capacity loss is proportional to the square root of time (e.g., 2 years would give 1.41 times the degradation seen at one year, meaning the second year would have 41% of the calendar loss of the first year)
Solar loading loss (i.e., parking the car in the sun) was estimated based on a study of the Prius battery (Media:HEV Battery Life.pdf) and scaled using average annual solar radiation from the NREL:
Average Annual Solar Radiation.png
The original version of the battery aging model was tuned empirically to reproduce as closely as possible TickTock's graph of Nissan data. In order to fit the graph, it was discovered that the following additional assumptions were necessary:
Calendar loss for the first year was 6.5% for the city with "normal" temperature
Cycling loss for the "normal" city was 1.5% for every 10,000 miles driven at 4 miles per kwh
Driving more efficiently than 4 miles per kwh would cause less cycling of the battery pack and reduce cycling loss proportional to the increase in efficiency. Conversely, less efficient driving would increase cycling loss
The Phoenix Arrhenius aging factor slightly overestimates the hot climate aging; it was necessary to scale the aging factors to fit Nissan's data. Note: The adjustment required the high aging factors like Phoenix to be scaled back (roughly 1.8 -> 1.5 for Phoenix on the scale we were using), although the model has the values adjusted to a slightly different baseline of 0.9 for "normal", so the actual scaled value for Phoenix is 1.35
The model was (October, 2013) updated and calibrated using Ah capacity measurements from Leaf Spy or the LeafDD. Using data reported from 22 Leafs (2011-2012 model years only), several changes were made to calibrate the model to fit the actual data:
It was discovered that scaling the aging factors for cities with climates warmer than Los Angeles caused the prediction to underestimate the actual loss. Therefore, unscaled aging factors were used for these warmer climates
Calendar loss was changed to 6.9% for the first year for the city with "normal" temperature (empirically derived to best fit the actual capacity loss data)
Cycling loss for the "normal" city was changed to 2.0% for every 10,000 miles driven at 4 miles per kwh (empirically derived to best fit the actual capacity loss data)
A correction factor was added to account for the fact that as the battery capacity diminished more full cycles would be necessary to drive a given distance (all other parameters being equal)
