1. Direct charging protection point voltage: Direct charging is also called emergency charging, which belongs to fast charging. Generally, the battery is charged with high current and relatively high voltage when the battery voltage is low.

2. The voltage of the equalizing control point: After the direct charging, the battery will generally be left for a period of time by the charging and discharging controller to let its voltage drop naturally. When it falls to the "recovery voltage" value, it will enter the equalizing state.
3. Floating charge control point voltage: Generally, after the equalizing charge is completed, the battery is also left to stand for a period of time, so that the terminal voltage falls naturally. When it falls to the "maintenance voltage" point, it enters the floating charge state. Currently, PWM is used. (i.e. pulse width modulation) method, similar to "trickle charging" (i.e. small current charging), when the battery voltage is low, it will be charged a little, one by one, to prevent the battery temperature from rising continuously, which is very important for the battery. It is very beneficial, because the internal temperature of the battery has a great influence on charging and discharging.
4. Over-discharge protection termination voltage: For the sake of safety, generally add 0.3V to the over-discharge protection point voltage of 12V battery as temperature compensation or zero-point drift correction of the control circuit, so that the over-discharge protection point voltage of 12V battery is 11.10V , then the over-discharge protection point voltage of the 24V system is 22.20V.