Performance Tools W2989 Battery Alternator Tester

Easy to use battery / alternator tester. Plug in to the 12V cigarette lighter in your car, the LED indicators will show you the status of your battery and alternator. 3 LED indicators to show the battery condition: weak, normal or strong. 3 LED indicators to check the status of the alternator voltage: low, normal or high. Works on any 12 volt system, compact design for easy storage. Compact size, a handy item for your glove box so you know right away if the problem you have is related to the battery or alternator.