LeftieBiker wrote:Driving doesn't appear to contribute to the battery overheating and actually helps cool the battery when the battery reaches higher temperatures.
This has been clear for quite a while, beginning with the 24kwh pack. In fact, I posited a while back that the accelerated degradation that users of Leaf to Home were experiencing was specifically because the cars weren't being air cooled by driving them while the packs were being drained. Driving can warm the pack, but that requires either a cold pack and hot ambient air, or extremely hard driving combined with warm or hot air temps. The rest of your test is very useful.
I performed another little test last weekend. I wanted to test the theory that short 5 minute waits before and after charging on long trips would improve charging speeds. I drove about 350 miles and I CHAdeMO charged 3 times, waiting before and after each charge.
At the beginning of the test the outdoor air temperature was a little above 80 degrees F but at the end of the test the temperature was a little over 100 degrees F. I drove back and forth between to charging stations that were about 90 miles apart. I drove the speed limit which was 70 mph most of the way.
My first charge started out at 30 kW, my second charge started out at about 20 kW but my third charge started out at 11 kW. On my previous test I drove a constant 60 mph and my charging speed never dropped below 14 kW. The test regarding the wait times was inconclusive but the battery temperature gauge did indicate that driving at 70 mph increases battery temperature, unlike the previous test where 60 mph maintain constant battery temperature.
So this test is validation of the hypothesis that you can use speed to control battery temperature. Driving slower improves charging speeds in two ways, the lower speed keeps the battery cooler allowing faster charging speeds and the lower speeds consume less power requiring less time to replenish the charge. For best speed you should always try to match travel energy consumption with charging speed (i.e. 14 kW at 60 mph with 14 kW charging) unless you can maintain very good charging speed, in which case you should drive at the fastest, safest legal speed.