Our commonly used car batteries are mainly divided into three categories, namely ordinary batteries, dry-charge batteries and maintenance-free batteries.

Ordinary battery: The polar plate of the ordinary battery is composed of lead and lead oxide, and the electrolyte is an aqueous solution of sulfuric acid.

Its main advantages are stable voltage and low price; its disadvantages are low specific energy (ie the energy stored per kilogram of battery), short service life and frequent daily maintenance.

Dry-charged battery: Its full name is dry-charged lead-acid battery. Its main feature is that the negative electrode plate has a high power storage capacity. In a completely dry state, it can save the obtained power within two years. When used, Just add electrolyte and wait for 20-30 minutes before using.

Maintenance-free: Due to its structural advantages, the maintenance-free battery consumes very little electrolyte, and it does not need to supplement distilled water during its 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 ordinary batteries. There are also two types of maintenance-free batteries on the market: the first one is to add electrolyte at the time of purchase and it does not require maintenance after use (adding supplementary liquid); the other is that the battery itself has been filled with electrolyte and sealed when it leaves the factory. , The user can't add supplemental liquid at all.