The 48v solar charge controller manufacturer tells you that 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 characteristics are different, so the charge controller used should be selected according to the battery type.

Charge and discharge protection:
1. Direct charging protection point voltage: Direct charging is also called emergency charging, which belongs to fast charging. Generally, the battery is charged with high current and relatively high voltage when the battery voltage is low. However, there is a control point, also called protection. The point is the value in the above table. When the battery terminal voltage is higher than these protection values ​​during charging, the direct charging should be stopped. The 48v solar charge controller manufacturer tells you that the voltage of the direct charging protection point is generally the voltage of the "overcharge protection point". The battery terminal voltage cannot be higher than this protection point during charging, otherwise it will cause overcharging and damage the battery.
2. The voltage of the equalizing control point: after the direct charging, the battery will generally be left for a period of time by the charging and discharging 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? The manufacturer of the 48v solar charge controller tells you that after the direct charge is completed, there may be individual batteries "lag behind" (the terminal voltage is relatively low). It is necessary to recharge with a high voltage and a moderate current for a short period of time. It can be seen that the so-called equalizing charge is also called "equalizing 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.
3. Floating charge control point voltage: Generally, after the equalizing charge is completed, the battery is also left for a period of time, so that the terminal voltage falls naturally. When it falls to the "maintenance voltage" point, it enters the floating charge state. Currently, PWM is used. (pulse width modulation) method, similar to "trickle charging" (ie small current charging), when the battery voltage is low, it will be charged a little, and when it is low, it will be charged a little, and it will come one by one, so as to prevent the battery temperature from rising continuously. High, which is very good for the battery, because the internal temperature of the battery has a great influence on the charge and discharge. The 48v solar charge controller manufacturer tells you that the PWM method is mainly designed to stabilize the terminal voltage of the battery and reduce the charging current of the battery by adjusting the pulse width. This is a very scientific charging management system. Specifically, in the later stage of charging, when the remaining capacity (SOC) of the battery is > 80%, the charging current must be reduced to prevent excessive outgassing (oxygen, hydrogen and acid gas) due to overcharging.
4. Over-discharge protection termination voltage: This is easier to understand. The 48v solar charge controller manufacturer tells you that the battery discharge cannot be lower than this value, which is the national standard. Although battery manufacturers also have their own protection parameters (enterprise standard or industry standard), they still have to move closer to the national standard in the end.