Originally Posted by gmeyers

By the by - mah or mAh simply refers to how many milliamps of current it has and can release in an hour at a given rate. Voltage is the power or push that a battery has - so a 2600mAh and a 1300mAh will have the same push , or power, at the same voltage but the 1300mAh battery will die sooner given the same load as a 2600mAh battery or even a 3500mAh battery. For more power or push add cells.
Lithium Polymer batteries are 3.7 volts per cell so a 3S liPo is 11.1volts but it's a difference that probably doesn't make a difference through a power panel. BUT for a starter it usually needs a bit more power to spin larger engines. a 12v lead acid battery fresh off the charger usually has a voltage of around 13.8volts and it levels off after awhile to 12.xxx volts. A LiPo at 11.1 volts probably won't spin an engine over 60 against strong compression (I use 14.8 volts) dynatron and Ryobi starters can handle up to 18 volts.