ITEM NAME:Battery low voltage warning module adjustable lithiu NiMH NiCD ion phosphate Ew Description: This module can give warning when your battery voltage is below your preset voltage. Any battery with voltage 6.5V - 30V Green LED - Battery voltage is greater than the threshold voltage Red LED - Battery voltage is lower than the threshold voltage For example, three lithium ion battery procedure: 1. The operating voltage for 3 lithium ion battery is 9V-12.6V 2. So, the warning voltage should be 9.5V 3. Apply a voltage of 9.5V and turn the potentiometer until it changes from red to green or vice versa A buzzer can be added to the module with a transistor to give sound warning together with LED warning Specifications Input: DC 6.5V - 30V Input with reverse polarity protection. Operating current: 1mA Size: 30mmx17mmx10mm Package Included: 1 x Module.A buzzer can be added to the module with a transistor to give sound warning together with LED warning. For example, three lithium ion battery procedure Input with reverse polarity protection. 1 x Module.