Lead-acid replacement battery, built-in BMS management system within the module, can implement all kinds of protection and protection recovery, and the module can be used directly in parallel. Lithium electric instead of lead acid, not only can save the battery space, reduce the battery weight, also has the long life, the wide working temperature range, supports the large current discharge and so on a series of advantages. It is applied to the area of room car battery and lead-acid replacement battery, which can be customized according to customer's requirements.