Cautions on Lithium Battery’s Series/Parallel Combination

Using Lithium Battery in series or parallel combination sounds simple, but in order to avoid unnecessary problem, it needs to follow some simple rules.

Do not mix cells of different brand or different capacity. Never use new and old batteries.

Choose battery cells with high uniformity. When battery has no enough capacity, replace all Lithium Battery Pack. When Lithium ion Battery is in series combination, make sure use the same type battery. Note that the pole of battery, if one battery cell is reversed, Battery Pack voltage will decline other than increase.

Mixing cells with different capacity or new and old battery, it will cause leakage, Zero voltage phenomenon often happens. This is because in the process of charge, capacity differences will lead to some lithium batteries over charged, someone not fully charged when recharge; some batteries over discharged, someone not fully discharged when discharge. Suffering from such vicious circle, battery will be damaged then leakage or low even zero voltage.

Usually lithium ion battery requires match when series or parallel combination, match standard, lithium ion cell voltage difference 10mV, internal resistance difference 5m and capacity difference 20mA.