To test a car battery with a multimeter, set the multimeter to measure DC voltage, and set the dial to 20 volts; with the car off, disconnect the battery cables and attach the multimeter leads to the positive and negative posts on the battery. Wait for the reading.Know More
With the car turned off, follow the manufacturer's guidelines for removing the battery cables. Note which is red for positive and which is black for negative. Always use safety gloves and safety glasses when working on a car battery.
Turn on the multimeter and set to measure DC voltage. For a car battery, this is indicated by the letter V with a solid line on top of a dotted or dashed line above the letter. Set the dial to 20v.
The red lead is positive and is to be attached to the positive post on the battery, usually indicated by a plus sign next to it. The black lead is negative and is attached to the negative post on the battery, sometimes indicated by a negative sign next to it.
After a few seconds, the multimeter will display the voltage measured. The minimum desired reading for a working battery is 9.6 volts.
When a car battery is overcharged, the most common effect is the battery rapidly dying, however, a battery that swells and becomes hot to the touch is also a direct result of overcharging. When the battery swells, sulfuric acid can leak from the battery. This is potentially harmful when it comes in contact with the skin and should be avoided if at all possible and if not, needs to be washed off the skin immediately.Full Answer >
The normal life expectancy of a car battery is typically estimated at four years when it operates under normal conditions. This means that the battery does not operate under extreme temperatures, is submitted to a full charge cycle and is not used to power excessive accessories.Full Answer >
To change a car battery, loosen the nuts that secure the cables to the terminals, and then lift the battery out of the car to exchange it for a new one. Wear gloves and safety glasses to protect yourself from acid leaks.Full Answer >
To recharge a car battery, clean the battery terminals, and connect a trickle charger to the terminals. Turn on the trickle charger, and allow the battery to charge overnight. Check that the battery is charged by turning on the vehicle.Full Answer >