In the process of using a solar charging controller, there are several voltages that must be understood.
A: high voltage protection voltage, in order to prevent the battery overcharge, generally in 15.5V. Some controllers do not have this function, or this function fails, which leads to battery bulging, and even failure.
Two: low voltage protection voltage, is to prevent the battery overdischarge and set the voltage. It's usually at 11 volts. Similarly, if you do not have this function, or the accuracy of components is not enough, the battery will produce over-discharge, usually the voltage of the battery is lower than 5V, it is difficult to charge back, will lead to the battery scrap.
Three: voltage recovery, which refers to the controller low-voltage protection, need to restore to a certain voltage value to work normally, usually the voltage is 12.5V, if not reached this low-voltage value, the controller can not automatically restore to work.
In order to use the battery longer, some people usually consult us. The low-voltage protection voltage of the battery is 11V, can you help me to lower it, such as 9V, so that we can use the battery for a longer time. The answer we all gave was no. Because 11V voltage point, is the battery almost used about 70% of the power limit. If you turn down the voltage, it will cause the battery to run in a state of loss for a long time, which will affect the life of the battery. All our low voltage protection, high voltage protection, the recovery voltage of the several values, we usually do not change according to customer requirements.