Dimmed car headlight

How To Test Your Auto Battery From your Chandler Texas Towing Company

When it comes to owning a vehicle, there are many things you can do in order to make sure that it is running properly. There are many moving parts to a well working vehicle, and while the list is long, regularly checking in on the small aspects can help keep your vehicle on the road and working efficiently for longer. For instance, testing your auto battery can help you avoid getting stranded somewhere and can also help you ensure that other parts of your motor are also working as they should.

How Does a Car Battery Work?

It takes a lot of energy to start and run a vehicle, and while most car batteries do only last between three and five years, that is probably longer than you would expect one to last that powered such a machine. The secret is that the batteries that run your vehicle are recharged as it is running by the alternator. The alternator is a type of generator that runs electrical currents back and forth between a rotor and a stator, allowing power to be created for your battery and other electrical components of your car to work.

Ways to Test Your Battery


One way to get an easy read on your battery voltage is to use a multimeter. In order to get an accurate read, be sure to check it when the car hasn’t been running for a while (at least over an hour, but best if tested in the morning before you start your car for that day). Your battery is likely located to either the far right or far left of the engine bay, but some models have the battery in a less disclosed position. If you are unsure where your car battery is located, consult the manufacturer manual.

There will be a positive (+) terminal and a negative (-) one. Typically, the positive terminal is covered by a plastic cover that clips on and off. Once both terminals are visible, be sure that your multimeter is set to 20V, and touch the red probe to the positive terminal and the black probe to the negative terminal. If your reading on the multimeter is a negative number, you probably have the probes switched. A good, adequately charged battery should be at 12.6V. If it is lower, then either you have a weak battery or something in your car is draining it while it is off (this is common in newer models). To know for sure, charge the battery and disconnect it from the vehicle. After letting the battery sit overnight, use the multimer again. This should tell you whether the battery is holding charge adequately or if the vehicle is draining the voltage.

Lights Test

If you do not have a multimeter, you can still test to see if your battery is holding charge based on how it powers the vehicle. After your vehicle has been sitting for a while, preferably overnight, turn on the engine and immediately turn on your headlights. If your headlights start out dimmer than normal but brighten as you rev the engine, it is possible that your alternator is actually supplying the power to brighten your lights and not the battery, meaning your battery is in need of a boost. If your headlights experience no difference whether you are revving the engine or not, it is likely that your charging system is working properly.

Get a Diagnostic

If you want to be sure your charging system is working properly, most auto retailers and mechanic shops will offer to test it for you. If you think your vehicle is suffering from a charging issue, then this would be the best way to know the exact source of the problem. Ask your mechanic about whether or not your charging system is working properly, and they will help set you up on the best course of action for you and your vehicle!

Has your battery run out leaving you on the side of the road with no way to charge it? Call Hi-Way Towing, a Tyler towing company, and have one of our drivers get to your location quickly with a professional jump box that will have you back on the road in no time.

Consider Hi-Way Towing as your Chandler & Tyler Texas Towing Company today!