GaslessInSeattle
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- May 6, 2011
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I have pondered this too, wondering if that design wouldn't backfire. hmm, yet another question for the wiki: frequency of using pre cooling at 100% SOC. I saw this mostly with prewarming on my first leaf. It appeared that prewarming after a 100% charge would allow the battery to get overcharged some, resulting in greater range, though I didn't have a gid meter to verify. I started timing the prewarming from a 80% charge and did a variety of experiments prewarming from 80% to 100% charge to attempt to raise the core temp of the battery in cold weather. while I did not want to overcharge the battery, I did find that prewarming for extended periods, from 80% SOC would warm the battery some and return some of the lost cold weather range.
If I lived in Phoenix or other areas with extreme heat, I'd do some experimenting with precooling from 80% or lower for extended periods and see if you can lower the temp of the battery or at least keep it from getting so high (wish we had the Leafscan to actually see the battery temp!). the car would of course have to be kept plugged in. conversely, I'd avoid precooling from a 100% charge in hot climates, as I am quite sure this allows for the battery to take on some excess voltage. super high heat and extra high SOC would likely compound the rate of degredation.
If I lived in Phoenix or other areas with extreme heat, I'd do some experimenting with precooling from 80% or lower for extended periods and see if you can lower the temp of the battery or at least keep it from getting so high (wish we had the Leafscan to actually see the battery temp!). the car would of course have to be kept plugged in. conversely, I'd avoid precooling from a 100% charge in hot climates, as I am quite sure this allows for the battery to take on some excess voltage. super high heat and extra high SOC would likely compound the rate of degredation.
Pipcecil said:I am curious as well why our gauges are 5% off, respecitively ~5% lower for each and every car. This could be the "software" bug that has been floating around on this thread. Regardless, that still doesn't address the accelerated loss occuring (it may not be as extreme but it is still significant). I am extremely afraid Nissan is counting the ~7% of our battery that cannot be accessed. To me, its very misleading to include that total since we would never be allowed to use it! But thats only speculation, and we can't verify that at all.
I do know that since I have owned the car, I am experiencing ~15-20 miles reduced capacity from new. That is with improved driving habits (finally hit 4 mi/kWh last month for lifetime average!), a very mild north Texas summer, and more chances to pre-cool/heat to extend my range. If I had retained the same level, I would be getting more range now. If I had lost only a few %, I think I would be having the same range with better "oustide" factors.
An interesting idea that occured that could relate to quicker degredation is "topping off" I am not aluding to plugging in the car to charge if 80% or greater capacity remains (something the manual advises to mimimize), but the use of the heating and cooling, especially on a 100% charged car. Everyone here knows that instead of creating a dedicated circuit to handle power from the outside source to run the A/C or heater, the LEAF uses the default set-up and pulls energy from the battery itself while the outside line recharges the battery. I recognize this when I precool my car in the morning for about 25 minutes with a the Level 1 (my wife uses the Level 2 for the volt). I am actually down some power (my time to charge will range from 10-40 minutes via Level 2 on the dash), once I was even down an addition fuel bar when I leave. If "topping off" is not ideal, why have this setup with easy access to climate control your car and encourage it to extend range!
It could be a compounded problem as the heat + the topping off occuring from using the CC together causes extra degradation? Its only a guess. If this was a greater factor than the heat (I doubt it) a proof of concept would be vehicles in extreme cold climates seeing battery loss from this next winter (cars would be a year+ by then too). If the idea does not hold clout then they will all drive happily to and from work!