You get in the car and notice the engine won't start and the headlights won't turn on. After doing the jump-start (starting the engine using another car battery), you need to find out if a new battery or alternator is needed or not. Follow these steps to check the car battery.
Step
Method 1 of 3: Checking the Battery Using a Voltmeter
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Step 1. Turn off contacts
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Step 2. Open the battery positive terminal cover
Check and clean the battery terminals.
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Step 3. Connect the voltmeter positive probe wire to the positive terminal of the battery
The positive probe wire on the voltmeter is usually red.
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Step 4. Connect the negative lead of the voltmeter to the negative terminal of the battery
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Step 5. Observe the voltmeter
If your battery is in good condition, the voltage should be between 12, 4 and 12.7 volts. A reading lower than 12.4 volts indicates your battery needs to be charged.
- If the measurement results are lower than 12.2 volts, do a trickle charge, which is a slow charging of the battery. Then check again.
- If the measurement exceeds 12.9 volts, you have an overvoltage. Turn on the headlights to eliminate over-voltage charging. Overvoltage can be an indication that the alternator is overcharging the battery.
Method 2 of 3: Checking the Battery Using a Power Probe
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Step 1. Open the battery positive terminal cover
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Step 2. Connect the Power Probe positive probe wire to the positive terminal on your battery
The positive probe wire on the voltmeter is usually red.
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Step 3. Connect the Power Probe negative probe to the battery negative terminal
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Step 4. Attach the tip of the gauge to the positive terminal of the battery
Observe the measuring device for voltage measurement results.
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Step 5. Observe the measurement results of the Power Probe
If your battery is in good condition, the voltage should be between 12, 4 and 12.7 volts.
Method 3 of 3: Checking the Battery by Cranking the Engine
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Step 1. "Crank" the engine by turning the contact until it starts and holding it for 2 seconds
Have someone crank the engine while you check the battery voltage drop.
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Step 2. While cranking, observe the measurement results of the Power Probe
The measurement result should not be lower than 9.6 volts.
A battery with a measurement lower than 9.6 volts indicates that the battery has sulfate deposits and cannot accommodate or accept charging
Tips
- Most car batteries last between 4 to 5 years. In hot climates, the battery can last only about 3 years. If you charge the battery and find that the battery cannot accommodate charging when the car is not started, replace the battery.
- If you get a new battery, be sure to dispose of the old battery according to the regulations in force in your country. Usually a parts store can handle battery disposal for you.
- You can check and charge the battery at the nearest spare parts store.
- Before buying a new alternator, inspect the system more thoroughly.