There are three commonly used charging methods for lead-acid batteries:

Pulse charging

This is a simple and economicalmethod, which has a large charging current and a fast charging speed.The disadvantage is that when thegrid voltage fluctuates, the charging current also fluctuates. It is easy to occur due to large charging current, high battery temperature, and large electrolyte loss, resulting in battery damage. Therefore, this method is rarely used for maintenance-free sealed lead-acid batteries.

Constant-current charging

In order to prevent the internal temperature of the battery from being too high and the loss of the electrolyte is too large, the charging current is adjusted to be small, so it takes longer to charge. However, If the charging time is too long, overcharge will occur. In order to prevent damage to thebattery due to overcharging, an overcharge detection or timing circuit is required.

Constant-voltage charging

When the voltage is lower than the upper limit of the charging voltage, the constant-voltage charging is safe. Even if the charging time is long, there is no danger. If necessary, the battery can work in the floatingstate.