Checking the car battery occasionally with a Multimeter is necessary to avoid the early morning struggles. Your car will not start if the battery is not working properly. In most of the cars, the battery is in the engine compartment. We can easily test the charge of our car battery using a Multimeter.
The basic things we measure are voltage and current. A Multimeter has three parts. The display that shows the values is the first part. Secondly, a selection knob will be there to allow the user to measure different values such as current, voltage and resistance. The third is the port that is in front of the unit. To test a car battery with a Multimeter we should first turn off the car. Follow the user guide to disconnect the battery which we get along with the car. Note the positive and negative sides of the battery (in the car) before removing. Use safety equipment such as gloves to remove the battery from the engine. We should set the Multimeter to measure the DC voltage. The black probe of the meter should be connected to the battery’s ‘-’ (ground) and the red probe to ‘+’ (power). Both the probes should be pressed against the battery terminals. If you’ve got a fresh battery, you should see around 12.6V on the Multimeter.
For measuring the current, first, we should set the Multimeter to 20DC Volt. Before measuring current we should check whether the battery is working or is a dead one. Touch the negative probe to the negative terminal of the battery and the positive probe to the positive terminal of the battery. Then turn on the switch to provide the battery with a light load. Check for the reading that is shown in the Multimeter. If it is showing a reading of 12.4 or more than that it means that the battery is having a good charge. If it is 12.3 means that the battery is 75% charged. If the reading is less than 12, it means that the battery is not good. Try slow charging the battery to see whether it is getting better. If not then we need to replace the battery. If you want to check whether the battery is producing enough current for the engine to start you will need help from someone. Ask him/her to start the car and you can check the measurement shown on the Multimeter.
If you are getting a reading below 10 VDC that means your battery is not capable of producing the needed current for the starter.If you want to know all the details read the checking car battery with multimeter article here.
The battery of a car can recharge while the vehicle is running and will give needed power to the electrical parts (head lights, brake lights, indicators etc.). If the battery is not good it will not get recharged automatically. The average lifespan of a car battery is 4 or 5 years. Battery service life can be estimated by analyzing the battery capacity using electronic battery testers.