When you go to start your car, you find that the headlights and engine won’t turn on. That indicates that the battery needs to be checked. And you should know how to check a car battery Not sure how to do that? Fear not—we will demonstrate, step-by-step, how to use a power probe or voltmeter to check the battery in your automobile. In the event that you lack any of those items, we will also demonstrate how to use the engine to check the battery.
Method 2: Check Your Battery with a Power Probe
Take off the positive terminal cap of the battery.
Attach the positive lead of the Power Probe to the battery’s positive terminal. Typically, a voltmeter’s positive lead is red.
Connect the negative lead of the Power Probe to the negative battery connector.
Attach the probe’s tip to the battery’s positive terminal. Verify the voltage measurement using the probe.
Verify the reading on the Power Probe. A battery in good condition should have a voltage of 12.4 to 12.7 volts.
Method 1: Check Your Battery with a Voltmeter
Switch off your ignition.
Take off the positive terminal cap of the battery. Verify and sanitize the battery connections.
Attach the positive lead of your voltmeter to the battery’s positive terminal. Typically, a voltmeter’s positive lead is red.
Connect the negative terminal of the battery to the negative voltmeter lead.
Examine the voltmeter
A battery in good condition should have a voltage of 12.4 to 12.7 volts. It indicates that your battery needs to be charged if the measurement is less than 12.4 volts.
You should “trickle charge” (a gradual charge) the battery if the reading is less than 12.2 volts. then make another check.
If the voltage reading exceeds 12.9 volts, it indicates an overvoltage. To eliminate excessive voltage surface charge, turn on the high beams. An excessive voltage could mean the battery is being overcharged by the alternator. Perhaps you should perform load testing as well, since you have the voltmeter at hand.
Method 3: Check Your Battery by Cranking the Engine
Turn the key to engage the starter and hold it there for two seconds to “crank” the engine. While you check the battery voltage drop, have someone to rev the engine for you.
Verify the Power Probe’s reading during the cranking moment. Never let it drop below 9.6 volts.
A battery is sulfated and is not holding or taking the charge when the volt reading is less than 9.6 volts.
As an alternative, you can get the battery checked out at a repair facility or car parts store. Usually, they test your battery without charging it.
Home diagnosis is not very accurate and can be quite challenging.