You guys had me all paranoid about LiPo batteries, but I have switched over to NiMH batteries for everything as a result. I use 3000 Mah batteries and I get bored driving the tank before the battery gives out. I have 3 of them so one is always ready to go.
I've only been tanking a few years but never have had a problem charging my batteries. I just set them on my bookshelf as they charge. I use a Venom Pro 2 charger and followed the directions. I think it's set for 3 amps charge current? I forget as I have it programmed in. Maybe it was .3. Whatever the instructions said (you just moved the decimal over per the mah of the battery).
I'm very tempted to do in-tank charging as it's a pain to have to flip the tank on its side to pull the battery pack.
Steve