openinverter forum

let me see if I can properly explain this, I will pepper in some name brands just in case that makes a difference or is of interest:

So say I charge my BMW 530e 9.1 kWh battery pack during the day to what I deem 90% full aka 393 volts for example. Then I let my truck sit over night. The next morning my Chevy Volt 1st gen charger will now report 389 volts. Alight, so here's the question, should I charge it some more, is it ok to charge it to 393 again? Or is this the equivalent of continuing to put petrol in your fuel tank after the handle has already clicked half a dozen times? ha ha

My approach is if I need the range yes I top off to 4.125v per cell before heading out, if I’m not in need of maximum range then I’ll leave it where it settles after charging to 4.05v per cell (normally settles to about 4v

Gregski wrote: ↑Mon Nov 20, 2023 6:19 pm .......
Alight, so here's the question, should I charge it some more, is it ok to charge it to 393 again? Or is this the equivalent of continuing to put petrol in your fuel tank after the handle has already clicked half a dozen times? .....

The range from 4V to 4.1V is so miniscule that it is just not worth cell life.
Charging over 4V means introducing mechanical stress into the battery which can degrade cell life over repeatable occasions.
Likewise leaving cells at 4.1V for prolonged time can likewise cause those mechanical tensions within and lower cell life.
I would rather not...