What are the methods of equalizing charging for lithium-ion batteries?

Currently, the following methods are important to charge each single cell in a series battery pack.

1. Add a parallel equalization circuit to each single cell of the battery pack to achieve the purpose of shunting. In this mode, when a battery reaches full charge first, the equalization device can prevent it from passing and convert the excess energy into heat, and continue to charge the under-charged battery. This method is simple, but it will cause energy loss. , Not suitable for fast charging system.

2. Before charging, each cell is discharged to the same level through a load one by one, and then constant current charging is performed to ensure a more accurate equilibrium state between the cells. However, for the battery pack, due to the physical The difference is that it is difficult for each cell to achieve a completely consistent ideal effect after deep discharge. Even if the same effect is achieved after discharge, a new imbalance will occur during the charging process.

What are the methods of equalizing charging for lithium-ion batteries?

3. Detect and evenly charge the single batteries of the battery pack on time, timing, and single sequence. When charging the battery pack, it can ensure that each battery in the battery pack will not be overcharged or overdischarged. This ensures that each battery in the battery pack is in a normal working state.

4. Using the time-sharing principle, through the control and switching of the switch components, extra current flows into the battery with a relatively low voltage to achieve the purpose of balanced charging. This method is more efficient, but the control is more complicated.

5. Take the voltage parameters of each battery as the object of equalization to restore the voltage of each battery to the same level. During equalizing charging, the capacitor is alternately connected to two adjacent batteries through the control switch, receiving the charging of the high voltage battery, and then turning to the low voltage. The batteries are discharged until the voltages of the two batteries tend to be the same.

The improved balance method can better solve the problem of unbalanced battery voltage, but this method is mainly used in occasions with a small number of batteries.

6 .The entire system is controlled by a single-chip microcomputer, and the single battery has an independent set of modules. The module manages the charging of each single battery according to the set program, and automatically disconnects after the charging is completed.


Post time: Aug-04-2021