The DC12/24V battery tester can accurately check the battery electricity status of car, truck, motorcycle. Checking the charger alternator. Operating range: 9.9V - 16.2V / 20V - 32.1V DC. High performance insulated pliers with 230mm 22 AWG wire for safe and easy use. 7 LED lights clearly show alternator battery status. Nickel-plated steel clips - Easy control and access to battery holders. Multiple functions: generator status check, battery status check, check before charging. The alternator check shows the status of your alternator based on the measured voltage. The external charge check indicates that the battery is charged when an external power source is used. If a DC lead acid battery or vehicle battery is used, battery problems can be quickly detected with this tester.