Features 【Protection function】The controller is designed to automatically turn off the power of the load when the battery voltage drops below a set value to prevent over-discharging. 【Automatic switch-on function】Once the battery voltage increases to a set value, the module will turn on the load automatically. 【LED indicator】The controller features an LED indicator that shows if the battery voltage is below the set value, making it easy to monitor. 【Adjustable voltage values】The turn-off and turn-on voltage values can be easily adjusted by pressing buttons. 【Battery protection】This controller helps to protect the battery from over-discharging, which can help prolong the battery's life. Features: This is a under-voltage switch controller used to turn off the power of load in the event of the voltage dropping below a set value. When the battery voltage increases to a set value, the module will automatically turn on load again. Designed with a LED indicator to show if battery is under-voltage. Both turn-off and turn-on voltage value can be adjusted by simply pressing buttons. This controller will help you to protect battery from over-discharging and prolong battery life. Specifications: Suitable Battery: 12V storage/lithium battery Control Current: 20A Control Precision: 0.1V Voltage Error: ±0.1V Size: 8*4.3*2.8cm/3.1*1.7*1.1in Weight: 41g(approx.) Restore to Factory Setting: At normal state, press and hold S1 and S2 buttons together, till display shows 888, to restore to factory setting. Package Includes: 1 x Battery Under-voltage Controller Package List