Understanding Basic LiPo Battery Specifications

by Kai Gottschalk

Many beginners to RC find it difficult to understand all of those pesky numbers in the description of many Lithium Polymer batteries. What are cells and what is the C rating?

Here is an example for a common hobby LiPo battery from Hobbyking.com:

To start:

Capacity

LiPo battery capacity is usually expressed in milliamp hours (mAh). This battery has 1600 mAh of capacity, meaning a device can draw 1600 mA for 1 hour. This number can be converted to amps (A), which is 1000 mA.

Cells

The cell count directly correlates to the voltage of the battery. Each cell is one physical LiPo cell, which are 3.7 volts each. This battery has 4 cells, meaning 4 physical cells of 3.7 volts each, in series. 3.7*4=14.8 volts.

Discharge (C-Rating)

The maximum discharge current of a LiPo battery is expressed with a C-Value. When finding maximum discharge current, multiply the C-Rating by the capacity of the battery in amps (mAh/1000). For this battery, it has a constant discharge C-Rating of 75, which means the battery can discharge a maximum of 120 amps (1.6*75). The burst discharge current is 150C, meaning the battery can output a maximum of 240 amps for 3 seconds.