25Hr should do it if its down to 1v per cell.

If you fly for a couple of hours and the battery is only half drained, you will need only 1000 mAh to recharge. Which would be about 12 1/2 hours. I would get a better charger anyway. You could charge your battery's in about an hour. You dont need a expensive charger, just something that will change at a higher rate, like maybe 5 amps. Look at hobbypartz.com for some good deals on chargers.

Maybe something like this??

http://www.hobbypartz.com/60p-dyc-1004.html