How to Troubleshoot Car Battery Problems
To identify a particular battery, you first need to know its cold cranking amps (CCA) and its date of manufacture. The CCA is on the label of the battery. A battery life expectancy begins when the sulfuric acid is placed in the battery, not when it went into service. If a four-year warranty battery is purchased and it sat on the shelf for a year, it has only three years of life left. Always look at the date on the battery to make sure it is fresh. The date is stamped on the top or side. It features a letter, which indicates the month--A for January and so on--followed by the year, denoted by the last two numbers.
Other People Are Reading
Instructions
-
-
1
Check the date to make sure it is not past due for replacement. Check the voltage across the battery terminals using the voltmeter. Connect the voltmeter's red lead to the positive terminal on the battery and the black lead to the negative terminal. The voltage should be 12.5 to 12.75 volts, if the battery is fully charged.
-
2
Have a helper start the car while you watch the voltmeter. When the starter is engaged to start the engine, the voltage will drop momentarily. Watch to see how low the voltage drops. The voltage should not drop below 10.5 volts if the battery is charged. If the voltage drops below 10.5 the battery has a bad cell and must be replaced. A battery may have several worn-out cells and still show 12.5 volts--it just won't have any amperage. The amperage is what is needed to start the car.
-
-
3
Check the voltage with the car running. The voltage should be 13.8 to 14.5 volts if the alternator is charging correctly. Turn on all the accessories--mainly the air conditioning and the headlights. The voltage should remain the same. If not, replace the alternator.
-
4
Check the water in the battery. Be careful because it is filled with sulfuric acid. The water should be the same level in the cells. If not, the battery has a bad cell and needs to be replaced.
-
1
