Rat wrote:Can battery life can be stretched by charging less often? I'm retired and seldom put in more than 10 miles a day. For longer trips I can swap cars with my wife anyway and she drives less than I do. I could go ten days (in theory) between charging, although of course I wouldn't cut it that close unless I was well under 100 miles in that period. But my question is, is that the best way to charge a battery to preserve life? Does it degrade a battery more to charge up from 90% to 100% 10 times or to go from 0% to 100% one time? Something in between? Jess, can you answer that?
Avoid running it down to 0% as much as you can; li-ion has no "memory", like ni-cd. Optimally, most li-ion EVs prefer to have as shallow of cycles as possible usually hovering somewhere around 60% charge. Most of the damage, however, is done at the very upper and lower ends of the charge range (near 100% charge and 0% charge, respectively). The far upper and lower ends are usually capped off, and what remains is known as the "depth of discharge". Sometimes the lower end isn't totally blocked from usage, but is left as an "emergency reserve". Given the numbers Nissan has provided, it will have a very high depth of discharge.
Basically, to sum up: Charge whenever you get the chance. It won't make a big difference, but if you're super-concerned, stop charging when you have enough charge that going half the distance you usually go in a day would bring you down to 60%. But really, it won't be worth bothering.