Car Problems? Check Your Battery

Many vehicle's electrical problems often start with the death of a battery – the one fix a person forgets to address. People will end up spending tons of money trying to diagnose their vehicle's failure to run when in fact, maybe the last time they had their battery replaced was over five or six years prior. Yes, car batteries need replaced just as flashlight batteries and such. But unlike flashlight batteries, your vehicle will rarely show signs of the diminishing power, it will suddenly just fail you.

While car batteries are much better today than they were even a few years ago, most fail in the 5-7 year range, if not before. And cheaper batteries might not last even that long.

Is your battery running at full capacity? A new 12-volt car battery, fully charged, should be putting out about 13.5 Volts. With the car running, by the way, the voltage should be 14.0 to 14.5 Volts, which also confuses a lot of consumers. A battery won't charge unless the voltage applied to it is greater than its basic voltage (otherwise current won't flow). So to charge a battery that is nominally 13.5 volts, you need 14 to 14.5 volts to make things happen. If the car is less than 14.0 volts when running, you may have an alternator problem.

With the car off, your battery should be at 13.0 to 13.5 volts, once it is charged. Anything from 12.5 to 13.0 volts is suspect, and if you are having problems and the battery is of any age at all, you should replace it. Below 12.0 volts, your battery is likely shot. You can use a voltmeter to test your battery, many automotive places have one and will test your battery for free. If your battery is at 11.5 Volts it may not start the car. Below 10.5 Volts it is basically dead and can cause things to happen to your vehicle such as the car alarm going off, lights blinking, etc. Most consumers imagine that a 12 volt battery is half charged at 6 and fully charged at 12, but the fact is it is fully charged at 13.5 and half charged at 12.


Car batteries do not have a lot of depth of charge which means this depth becomes shallower over time. As a car battery ages, it may hold little more than a surface charge. There is enough charge to crank over the engine and start the car - once - before the alternator kicks in and recharges the battery, which in turn will now have just enough charge to re-start the car. Draining your battery becomes easy to do – whether it is a cold day and your engine has to work harder to turn over or if you leave your dome light on too long.

If your vehicle has an aftermarket stereo installed, these tend to draw more power from your battery, even when it is off. Navigation systems can also draw a lot of power. People with subwoofers often install a separate battery to power them. The standard car battery can easily be drained flat by large aftermarket subwoofer amplifiers and other audio, video, and navigation accessories.


Changing your own battery does require some knowledge in how to do it properly. If you are not familiar with what that is or how you could easily short circuit your battery or vehicle, you may want to allow a professional to do it for you. If your battery is over five or six years old, you may want to have it tested. After all, it would be cheaper to have it replaced than to pay for towing.

Greg Chapman of Greg Chapman Motors is a knowledgable and leading provider of used cars, trucks, and SUV’s. Since 1959, Chapman motors has supplied reliable used car Austin and the surrounding area. For more information please visit http://www.gregchapmanmotors.com.