This is a great pick when it comes to a car battery tester and gets its operating voltage from the battery. The device is able to test 12-volt batteries and allows you to test the CCA. You simply enter the battery’s CCA rating into the device and then get a reading of the actual CCA via a conductive test. The Solar BA7 will then give you an ‘Ok’, or ‘Fail’ reading and allow you to determine the health of your battery. This is a quick and easy to use automotive battery tester and will enable you to analyze your vehicle’s charging and starting system. While it costs a little more than some of our other picks, it is durable and accurate.