I know people who do it, but I wouldn't recommend it. A rechargeable battery can only hold so much current. After that, excess internal gas is formed, and the battery pack could explode. I don't think it would be good on it at all. My suggestion is to do what I did--get yourself a quickcharger. Plug it in on the way to the field, and it's charged by the time you get there. Also, you can recharge at the field that way as well! Solves many problems. Then, what I do, is recharge my batteries when I'm done flying for the day (with the field charger), and when I get home, my wall warts are on a timer--they come on for a couple of hours per day. That way, when I get ready to go out next time, they are all ready to go! In my situation, this all takes place in my trailer, but you could easily do it in the house or workshop--wherever you store your planes.