Typical Terms found on LiPo batteries cells are:
Cells in Series – A 4s LiPo battery pack, for example, would have a total of 4 LiPo cells electrically wired in series to make a complete battery pack. Each Lithium Polymer cell has a nominal voltage of 3.7v. A 4s pack would be rated at a nominal voltage of 14.8v. 4s2p LiPo battery pack would mean two 4s packs in parallel. A LiPo pack in parallel doubles the capacity, and discharge rate. Total nominal voltage and C rating remains the same. 2S lipo batteries each would add to 10 000mAh in total.
C Rating – The C rating of a Lithium Polymer LiPo Battery Pack is specific to the maximum continuous rate of discharge the battery can perform safely. The recommended maximum discharge for a LiPo is calculated using the C rating and battery capacity. A 25C 5000mAh battery has a max discharge of 5Ah * 25C = 125A.
mAh – mAh stands for milli-amp-hour. In simpler terms it is best related to the capacity of the LiPo battery Pack. A higher value would result in delivering an equal amount of power for longer. A 5000mah lipo 2S would deliver (1000mA) 1 Amp for 1 hour.
Selecting the Best LiPo Battery Pack for your RC application.
It is highly recommended to use the highest capacity LiPo cells as possible with C ratings of 25 or higher. In most cases the only reason to use cells of a lesser capacity or discharge rating would be for weight and size savings. C rating is usually a matter of budget. They effect weight at a small level and do effect cost at a higher level.
LiPo Battery Packs with a larger mAh rating will naturally be heavier and have a larger physical size. Choose cells that will fit in the location they are intended to be in.
One thing that is really important with charging LiPo batteries is to use a charger designed specifically for LiPo batteries, and with most LiPo-specific chargers it's necessary to correctly select the cell count. Though most good chargers are able to do this automaticly now .Chargers Tend to constant current charge to 75% of the cell capacity until the pack voltage reaches 3.6 volts per cell. This charges the pack to about 80% of total capacity. The the charger will switch to a constant voltage charge rate of 3.6 volts per cell to top off the battery. To fully charge an empty pack normaly takes about one and a half hours. Also it is vital to have a ballancer on your charger if you us packs of more than 2cells this makes sure that the cells have the same charge in each cell
If LiPo batteries are improperly charged they can in the right conditions explosive. It is imperative the importance of using a charger specifically designed to charge LiPo batteries, and to be positive that the manual cell count (if the charger has one) is correctly set for the specific battery being charged. If you use a good quality LiPo charger, these batteries are totally safe.