Re: 2019 Leaf battery overheating
Posted: Mon Jun 08, 2020 8:00 am
Where're your anecdotal data? Provide images of the bottom of the Leaf which indicate how under body air flow can contribute to cooling.
Right, at less than 50 MPH, and under ideal driving conditions!
Again, where're your anecdotal data? Guessing is not allowed! Tell us what the resistance is and how you determined the "low" battery heat.GerryAZ wrote: ↑Sun Jun 07, 2020 10:55 pmThe internal resistance of new (not significantly degraded) LEAF batteries is quite low. The internal resistance increases as the batteries deteriorate so 8-capacity-bar batteries will generate more heat during discharge from highway driving (and especially from QC charging) than 12-bar batteries, but the internal resistance of even an 8-bar battery is still relatively low.
Yes, that's been stated many times on MNL, and is basically intuitive to most! It doesn't really contribute to your thesis.GerryAZ wrote: ↑Sun Jun 07, 2020 10:55 pmIf the battery is cool, then highway driving will increase battery temperature until it reaches an equilibrium temperature enough higher than ambient to cause heat transfer through the thermal resistance(s) between the cells and ambient equal to the heat generated internally. The battery cells together make a large thermal mass so that large mass heats and cools slowly, but the heat transfer is dependent upon the temperature differential between the cells and ambient. In normal day-to-day driving, the battery will cool while the car is parked overnight, but battery temperature will ratchet up during a long trip with multiple QC's because more heat is generated during each QC than dissipated by driving between QC's.