In order to protect the battery and prevent overcharging, most solar power generation systems include a charge controller. Its most basic function is to cut off the charging current when the battery is full. The battery type selects the charge controller used.

Equalizing charge control point voltage: After direct charging, the battery will generally be left for a period of time by the charge and discharge controller to let its voltage drop naturally. When it falls to the "recovery voltage" value, it will enter the equalizing state. Why design equalizing charge? That is, after the direct charging is completed, there may be individual batteries "lag behind" (the terminal voltage is relatively low). The current is recharged for a short while, and it can be seen that the so-called equalization charge, that is, "equalized charge". The equalizing time should not be too long, generally a few minutes to ten minutes. If the time setting is too long, it will be harmful. For a small system with one or two batteries, equalizing doesn't make much sense. Therefore, the street light controller generally does not have equalization, only two stages.