Testing a car battery with a multimeter is quite easy with the necessary guidance. A multimeter is a tool that we would recommend in every house and it can measure electrical quantities like voltage, current, and even resistance. The ideal voltage for a car battery would be around 12.5 volts.
Also, care must be ensured that the battery should be sufficiently rested before measuring the voltage. We recommend measuring after leaving the car unused for a few hours. If you find the multimeter readings a bit too complex to make sense of, it is nothing to worry about. In this article, we will be providing you with everything you need to know while testing a battery with a multimeter.
What is a Multimeter?
A multimeter is a testing device that can measure Inductance, Temperature, Frequency, Resistance, Current, Capacitance, and much more. They have both digital and analog versions. Moreover, additional accessories can be used with a multimeter to obtain properties like Acidity, Alkalinity, Wind Speed, etc.
Setting up the Multimeter
The multimeter might look seemingly complex, but the operation is fairly easy. The DC Voltage is indicated with a solid and dashed line above the V alphabet. First of all, set the dial to 20. This allows for accurate measurement below 20 volts. Now, connect the red probe to the positive terminal and the black probe to the negative terminal. If you don’t know, the red terminal is positive, and black is negative. If you are getting a negative reading, it means the connection should be reversed.
Using a Multimeter to Test a Battery
- Switch on the headlights for 2 minutes. This will help to remove any surface charge in the battery.
- Adjust the multimeter to about 15-20 Volts.
- Switch off the headlights.
- Hook the multimeter to the battery terminals.
- Read the voltage and see whether it is around 12.5 volts.
- Run the car and check for the new voltage.
- If the voltage level drops below 5, it is not good and the battery ought to be replaced as fast as possible.
- If the battery is not working properly, then it might be time to check the Alternator. The alternator charges the battery. First of all, turn on all the headlights, and other electrical appliances in the car. If the multimeter reading is less than 13.5, then the alternator is faulty and ought to be replaced.
How to Check if the Battery is Bad?
A bad battery displays some of the following symptoms.
- Dim lights
- Issues starting the car.
- Car requires jump-starts.
- Clicking sound while turning the engine.
- Illuminated battery light on the dashboard.
- The engine is slow while starting.
How Many Volts is Ideal for a Car Battery?
While the engine is running, the voltmeter should measure between 13.6 and 14.7 volts. For a rested battery, this should be around 12.6 volts.
How Long Should a Good Quality Car Battery Last?
Usually, a car battery comes with a warranty period of 4 years. However, not all of them make it past the time period. Anything above 4 should be considered a bonus.
We hope you enjoyed this read on measuring the voltage of the battery using a multimeter. You might find the procedure a bit tricky at first, but it is rather easy once you learn how to read the multimeter. For any queries, do contact us.