The battery packs in an electric vehicle must be as constant as possible in the capacity of each battery to avoid long-term overcharging and overdischarging between batteries. Balance should be performed every three months to keep the voltage as constant as possible. The calibration method is tested using a multimeter with one or more 12-volt chargers and a 100-watt incandescent lamp. The multimeter detects the consistency of the voltage, charging the battery at a lower voltage, and discharging the incandescent lamp at an excessively high voltage. This process is very time-consuming and requires hands-on work skills and relevant professional knowledge. Special attention: people who do not understand the relevant knowledge should not perform this task. Failure of this process is very dangerous. If possible, you can design a simple balance adjuster. However, this kind of balancer is sold in the market, but the price is a bit more expensive, and the effect has not been verified. If conditions permit, there is a faster and more convenient way of operation, which can be balanced by installing the charger (single battery) on one battery and connecting the single battery at intervals.

　　Avoid severe vibration. The active material of the battery plate will expand and loosen during the charging and discharging process, and the active material will fall off and damage the battery when vibrated severely. The riding speed should be slow, not suitable for walking on very bumpy roads. Or install a stabilizer at the location of the battery to avoid vibration.