The lead-acid batteries commonly used in diesel generator sets are mainly divided into two types: dry load batteries and maintenance free batteries.

1) Dry charged lead-acid battery: Its full name is dry charged lead-acid battery, mainly characterized by the high storage capacity of the negative electrode plate. In a completely dry state, it can store the obtained electricity for two years. When in use, only add electrolyte and wait for 20-30 minutes before use. Its main advantages are stable voltage and low price; The disadvantages are low specific energy (i.e. the energy stored per kilogram of battery), short service life, and frequent daily maintenance.

2) Maintenance-free batteries: Due to their structural advantages, maintenance free batteries consume very little electrolyte and do not require distilled water supplementation during their service life. It also has the characteristics of shock resistance, high temperature resistance, small size, and small self discharge. The service life is generally twice that of a regular battery. There are also two types of maintenance free batteries on the market: the first type is to add electrolyte at the time of purchase and do not require maintenance during use (adding supplementary liquid); Another type is that the battery itself is already filled with electrolyte and sealed when it leaves the factory, so users cannot add any replenishment solution at all.

Lead acid batteries come in 2.4V, 4V, 6V, 8V, 12V, and 24V series, with capacities ranging from 200mAh to 3000Ah. Generally, diesel generator sets are started using 12V or 24V batteries.