Car Battery Tester

By Jason Miller

Today's automobiles are sophisticated machines with GPS navigation, LCD screens, DVD players and iPods. However, all of these 21st century technological wonders are still at the mercy of the car battery and the automobiles electrical system. Car batteries have improved over the years but the technology is basically the same. Most of us do not even think of our car battery until our reliable car refuses to start and we are stranded in a parking lot. A modern car battery tester can evaluate trouble with your automotive battery and determine the correct course of action a technician needs to take.

Car battery testers use the BCI adjustable load test as a measurement to decide if your car's battery is usable or needs to be replaced. The car battery tester measures the voltage drop when an applied load that is ½ the car battery's CCA rating is used. The load is applied for at least 15 seconds and the voltage drop is measured. The voltage should not drop below 9.6 volts for the battery to be considered good. (Also the ambient temperature should be around 70° F) For example, you have a battery with Cold Cranking Amp rating of 600 CCA. You would apply a load of 300 amps for 15 seconds. If the measured voltage does go below 9.6 volts, the battery is still good. It is possible to use a car battery tester in differing temperature conditions, but you must compensate for the difference in your calculations.

If the car battery has been completely discharged, you will have to recharge it using a suitable car battery charger. Do not attempt to use a quick charger type battery charger if yours is in this condition. These types of automotive battery chargers use a high current to get you fast results. This high current can damage the sensitive plates in your battery when it is in a fully discharged state. Another method to avoid is just to get a pair of jumper cables and jump start the dead car and then let the alternator recharge it. Your car's alternator is not a car battery charger and it cannot recharge a totally discharged battery without getting damaged. Be sure to let the battery cool down to room temperature. People often forget how hot it gets inside of an engine compartment, especially in the summer months. That goes for cold weather as well. You may have to let the battery warm up to room temperature. Batteries perform differently at temperature extremes and that's why its important to use room temperature as the standard to accurately measure them.

About the author:

Jason has been in the construction equipment and industrial sales business for over 10 years. He owns and operates Red Hill Supply to better serve the automotive and industrial industries. - Automotive Tools