aarond12 wrote:It was odd to me that the Mitsubishi i-MiEV had full regen (running in "B" mode) even when the battery was full. I guess Mitsubishi realized that, on flat terrain, it takes more power to make the car go than can be regenerated. On a mountain, sure, that's not going to allow regen past 100% charge. It seems that Nissan is just being much more conservative than Mitsubishi was.
That means 100% charge is not 100% for cells. iMiev charges to around 4.115 volts per cell. Controller may allow to go higher.
4.2V is still safe for lithium cells.
Chevy Volt uses even more narrower SOC window. Regen is totally available at "full charge".
Leaf also charges cell up to 4.135V. But controller does not allow go above that even during regen.
It is not the maximum SOC voltage that degrades cells. it is the time at that voltage.
iMiev expects you to waste that extra 0,5kWh you get if you go down the hill. Pretty reasonable.
Cell chemistry is also a player.