Li-Polymer Battery Knowledge

Li-Polymer Battery Knowledge

1) What’s Rated Capacity?
 
The rated capacity of lithium polymer battery means total quantities of electricity or energy that can be withdrawn from a fully charged cell under specified conditions of discharge current. Rated capacity express by ampere-hours (Ah) or milliampere-hours (mAh) and energy quantity express by watt-hour (Wh).

2) What’s Cycle Life of the battery?
Generally, the capacity of secondary battery reduces as it continues charging and discharging. For example, the rated capacity of the battery is 1000 mAh, however as we charge and discharge for many times, it gets decreased as 980, 950, 900 mAh gradually. In general, cycle life is defined as the numbers of charging and discharging until the original capacity reduces to its 60~80 % under the condition of 100% depth of discharge. For example, if the cycle life is 1000 times, means that under the condition of 100% D.O.D. But, in reality, it is general that we recharge it after using its capacity only 70-80 %. Under the condition of 80 % D.O.D, the cycle life increases many times over. Cycle life is the performance indicator that is based on this definition.
 
3) Why will discharging capacity decrease at low temperature?
Generally, the capacity of battery decreases rapidly at low temperature. For example, the rated capacity of the battery is 1000 mAh, however it might be withdraw only 40~50% of the total quantities of electricity or energy because of the materials of the battery become inactive.