i use a RS universal for charging...i recommend that you dont charge the car at more than 4.5v. and DONT run more than 3v into the controller or you will be down a controller. Bottom line the controller blows above 3v just dont do it take my advice or take my box of fried controllers! . the mah doesnt matter just changes charge time. actually if i were to recommend something buy the ??volt that you need for that specific job, i found out the hard way switching down on my universaal. they also fit in the case mine doesnt