Can xomebody excplain about the mah of the battery?

I have 1 lith-pol 1500mah 2 cell Electrifly and was wondering the difference between one that is 1500mah with 1 cell up to 3 cell batteries? I am getting a ni-mh 650mah battery with my rc heli. So, with one with more cells last longer or shorter?

The MAH is the same but the voltage is different the two cell will last longer than the single cell will and the LiPo battery will last longer and have much more power than the NiMh battery.The Mah is the Millieamp hours of the battery and the discharge rate,the lipo has a much higher discharge rate than the Nimh but be careful Lipo batterys can be very dangerous if not used properly.2c lipo's are usually 7.4volts and1c are usually 3.7 volts.The 2c will be your best bet for the most power.