Easy-to-use battery/alternator tester - simply plug into 12V cigarette lighter in your car.
LED indicators will show you the status of battery and alternator.
Features 3 LED indicators to show the battery condition: weak, normal, or strong; and 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 - a handy item for your glove box so you know right away if the problem you have is related to the battery or alternator.