Lead acid batteries have been used for the longest time among various types of batteries, and are also the most mature and cost-effective battery in terms of manufacturing technology. Lead acid batteries have been produced in large quantities, and early electric vehicles mostly relied on lead-acid batteries as their energy source. However, lead-acid batteries have low specific energy, short single charge driving range, high self discharge rate, and low cycle life, which are not suitable for the development needs of modern electric vehicles. At present, lead-acid batteries are mainly used as the starting power source for internal combustion engine vehicles.
Classification of lead-acid batteries
(1) Maintenance-free lead-acid batteries
Maintenance-free lead-acid batteries, due to their structural advantages and low electrolyte consumption, do not require additional distilled water during their service life. Maintenance-free lead-acid batteries have the characteristics of shock resistance, high temperature resistance, small size, and small self discharge, and their service life is generally twice that of ordinary lead-acid batteries. Maintenance-free lead-acid batteries can be divided into two categories: batteries with added electrolyte at the time of purchase and batteries that have already been filled with electrolyte at the factory.
(2) Valve controlled sealed lead-acid battery
Valve controlled sealed lead-acid batteries do not require the addition of sulfuric acid or water during use, and the battery structure has good sealing performance, without acid leakage and acid mist discharge. The battery cover is designed with an overflow valve (safety valve). When the internal gas of the battery exceeds the limit, the overflow valve will automatically open for exhaust, and after exhaust, the overflow valve will close. Valve controlled sealed lead-acid batteries can be divided into two categories: fiberglass batteries and colloidal batteries (silica coagulants).
