What is the available capacity and remaining capacity of lithium batteries?

The available capacity may only be 80-90%. The chemical capacity of lithium batteries is measured when the current is very low, and it is more determined by the characteristics of the battery itself. In fact, during the actual use of lithium batteries, due to a certain discharge current, the discharge curve will be lower than the open circuit voltage curve. This curve shows that due to the presence of internal resistance in the battery, the actual discharge curve is blue, and the blue and red curves correspond to Quse, which actually refers to the available capacity of the battery. In this curve, we found that due to the presence of internal resistance in the battery, the position of this curve moves downwards, so the discharge will reach the discharge termination voltage earlier, that is, it will reach the EDV earlier. So Quse is generally smaller than Qmax.

The remaining capacity refers to the capacity of the battery to be placed in the EDV in its current state, which is the termination discharge voltage. In the figure, the current state A is released at the given current. When the discharge reaches 3.0V, the corresponding remaining capacity is recorded as R1. If a larger current is released in state A, the position of this curve will be slightly lower than the open circuit voltage and also slightly lower than the position corresponding to the discharge of small current RM1, then the remaining capacity obtained at this point is RM2. The difference between RM2 and RM1 lies in the different discharge currents used. The larger the discharge current, the lower the curve position, and the smaller the remaining capacity. Therefore, the remaining capacity of the battery is related to the discharge rate, and the remaining capacity of the battery varies under different currents.

Guangzhou Battsys Co., Ltd (NEEQ:837375), was founded in 2006, which is a join-stock high-tech enterprise engaging in ODM and OEM , specially for customized and diverse research&production of lithium-ion battery，BATTSYS annual production capacity is tens of millions battery cells. The products are exported to dozens of countries & regions such as Europe, America & Asia etc.