I'd love to go lipo, and I don't mind spending money if that produces more runtime, but my conern with lipo, based on what I read, is that you cannot leave them charging longer than a certain amount of time, and that you cannot let them discharge completely. If this is correct, this means I cannot leave them charging at night, and that I have to pay attention that I stop running in time before they die completely. Isn't that annoying? I personally would even buy two of these: MaxAmps Lipoly 12000mah 2S3P 7.4V Pack. But they cost so much that I don't want to break them after one run just because I was distracted and left them connected to the engine for too long...

Anyway, how long does it take to charge a 6000mAh lipo battery, for example?
And, is there any lipo battery charger for cars?