On standard L2 - there is no appreciable heat generated from 80-100%. QC - yes. L2 - you're not going to see a difference between it an L1 the charge rates are so low. Will have to ask Ingineer to do some data logging of pack temperature during a L2 charge...spooka said:I was told this also by a Blink/Ecotality tech that I met a the 101/17 QC station at Bell Ford about a month ago. He said this was especially an issue with QCing. I am thinking that the best way to combat the heat issue when charging beyond 80% is to L-1 charge to keep the heat as low as possible.leafkabob said:because the only problem with charging to 100% is the amount of heat that is generated between 80% and 100%. The ABC Nissan leaf tech that was helping with this was nodding his head in agreement at this remark.
Edit: Asked and Phil was quick to answer (Thanks Phil!):
Ingineer said:The 2 rates are so close that the difference isn't really observable. Keep in mind, while the L1 is a lower rate, it's doing it for longer, which seems to tie with the L2 rates because they finish a lot faster.
Now if it was really cold/hot out, these numbers may change, but here in NorCal, I don't notice any difference. Even when I charge at 6.7kW!
The battery has a certain resistance, and it's got a LOT of thermal mass with little effect from the outside air, so it's pretty linear up to the point where the chemistry non-linearity starts to affect it. (Which probably doesn't start until around 1/2C rates)
There's a reason why the service manual says to check for cell voltage differences with 2 SOC bars or less. I'd argue that it should be done at LBW or lower, preferably at VLBW or lower. 100% is not effective because the LBC should be actively balancing the cells.vegastar said:Making a cell voltage difference at 383.53V total pack voltage is not effective. 383.53V/96 = 3.995, very close to the maximum, so the minimum cell voltage is an outlier and the maximum cell voltage is the norm. 24mV difference from the average cell voltage is equivalent to 381.22 total pack voltage if all the cells were like the weakest one. This 2.31V difference is around 1 kW.h of energy, so around 5% total pack capacity. I think the cell voltage difference must be done in 100% charge to check for imbalances, and around the knee of the voltage (3.71V) to check for damaged cells.