Scope Mainly used in battery 9V or 12V voltage monitoring simple and practical support sound and light alarm Features When the buzzer low voltage will DiDiDi sounds and the red LED lights up when the battery voltage rise above to the set value buzzer will stop alarm Size 2 9 x 3 cmThe main chip LM3589V Battery When a battery over discharge battery voltage drops below about 8V the red lights and the buzzer calling to achieve sound and light alarm to achieve control battery discharge status prevent over discharge battery and damage battery 12V Battery When a battery over discharge battery voltage less than 10 4V the red lights and the buzzer calling to achieve sound and light alarm to achieve control battery discharge status prevent over discharge battery and damage battery Advantages With a sound and light alarm simple and practical The module input with reverse protection if reverse polarity power input will not burn But without overvoltage protection if the input exceeds 15V the chip above the module will burn out Adjustment method 9V Battery Input 9V the LM358 voltage adjustment between 2 feet and 4 feet to about 5 78V the alarm voltage is 8V we has set it before shipment so you dont need to adjust it again Clockwise adjustment 2 feet and 4 feet voltage is reduced the sensitivity increased 12V Battery Input 12V The LM358 voltage adjustment between 2 feet and 4 feet to about 6 05V the alarm voltage is 10 4V we has set it before shipmen