That's per cell right?

mAh = milli-amp per hour - or loosly speaking how much charge the battery holds, a higher number will run longer. How often will depend on your buggy and even how long you let it sit between runs.

I just use 4 aa (NiMH) cells of 2400mAh each. Not sure how many runs I've done on one charge ... too many to worry about how often they need recharging with a 1hr charger.

Craig.