Sorry for interfering, but maybe I can help with lithium batteries thing. First of all, Lithium is not the best chemistry to use, but it keeps being manufactured because energy density compared to other elements. That said, important temperature changes are always bad for this kind of batteries. The further away (hotter or cooler) from 15 or 20 Celsius degrees, the more it degrades over time.
I'm not aware about last technologies regarding this (it's supposed that electric car manufacturers and other people are trying to improve it), but I don't think it's a good idea to have one of this batteries always inside a car if it reaches high (or extremely low) temperatures.
By the way, hotter is always worst than colder, and any bloated battery is dangerous (it means that the pressure inside has increased a lot, that the cells are degradated and that is a real danger of fire or explosion).
One last interesting point is that optimal charge lvl for battery conservation is about 50%-80% (not 100%, because the cells pressure) and it is advisable to don't go under 15% when possible.