LiPo batteries (short for “Lithium Polymer”) are the latest and greatest when it comes to battery technology. When considering power to weight ratio, LiPos are far superior compared to NiCad (Nickel-Cadmium) or NiMH (Nickel-Metal Hydride) batteries.
There are several options when choosing a LiPo battery. The first is the voltage level that the propulsion system runs at. A single cell LiPo battery outputs 3.7 volts. To increase the overall voltage, LiPo cells are connected in serial. Connecting the LiPo cells in serial, cumulatively adds to the overall voltage. For example, two 3.7 volt LiPo cells will output 7.4 volts and a three LiPo cells will output 11.1 volts and so on. For Scout, the motors and Electronic Speed Controllers that I have chosen run at 11.1 volts and so I chose 11.1 volt battery.
The second option is capacity. Capacity is how much power the battery can hold measured in milliamp hours (mAh). For example, a LiPo battery rated at 1000 mAh will discharge in one hour with a 1000 milliamp load placed on it. If the same battery had a 4000 milliamp load placed on it, the battery will discharge in 15 minutes. The higher the capacity of a battery, the longer the flight time, but also the bigger and heavier the battery will be.
The third option is discharge rate. Discharge rate is how many amps can be discharged at a time. The discharge rate is multiple of the total capacity of the battery and represented as the “C” rating. For example, a battery with a capacity of 2000 mAh and a discharge rate of 10C is capable of withstanding 20,000 milliamp or 20 amp loads.