Battery mAh rating is the duration (MilliAmp Hours) and directly refers to how many milliamps the battery can deliver over an hour. The higher this figure, the longer the battery will last. This is largely linear, therefore a 3000mAh battery will last 3/5ths as long as a 5000mAh. Remember also that the duration affects the current rating. If both batteries are 20C, then the 5000mAh delivers 100A (5A*20C), and the 3000mAh delivers 60A (3A*20C). Use this formula to work out the current handling characteristics of any battery (mAh*C= maximum Amps delivered).
Last edited by Foxy; 07-23-2014 at 11:15 AM.