Every driver should know how to test a car battery. If you’re having trouble starting your car, you smell a bad odor coming from under your hood, or your dashboard warning light comes on, the first step you should take is to test your battery. You can do this using an ohmmeter, a simple device you can buy at any store that sells auto accessories. To use the ohmmeter, turn your engine off—along with any electronically powered functions, such as your headlights—and lift the hood of your car. Then, set your ohmmeter to about 25 volts. Attach the ohmmeter’s positive cable to the battery’s positive terminal, then do the same for the negative cable and the negative terminal. If your reading shows that your battery is 12.5 volts or higher, your battery is at 75% capacity or higher; if it’s 12 volts or lower, your battery is low or dead. If your car’s battery or electrical system is in need of professional attention, bring it to a qualified auto shop in Sacramento.