In this article, we’ll tell you how to properly check if there are any problems in your car battery with the help of a multimeter and battery load tester. We’ll also tell you what ways of checking a car battery there are.
How to Check a Car Battery With a Multimeter
First of all, you’ll need a multimeter – a special device for measuring voltage. If you don’t have it, buy one in a shop or borrow from a friend. This device is not expensive. Besides, in case you constantly fix electrical devices, you’ll need the device as well. We recommend you buying a digital multimeter since it’s easier to use.
You shouldn’t trust the device that there is on a dashboard of your car to measure the voltage of your car battery. The thing is that the value very often turns out to be incorrect. This happens due to the fact that the voltmeter of your car is not connected directly to the car battery. Consequently, the value may be inaccurate. The voltage value may be lower than it really is.
Checking the Car Battery When the Engine of the Car is Running
The voltage value of a car battery in case the engine is running should be from 13,5 to 14,0 V. If it’s higher than 14,2 V, it means that the charging level of a car battery is low and that the alternator is working on its highest operating abilities in order to charge the battery. However, this is not always the reason for increased voltage. For example, in winter, the voltage may be increased due to the fact that a car battery turned out to be discharged during one night because the temperature is below zero and the weather is very cold. Moreover, the temperature may be measured by the electrical device of your car. This device, then, allows the battery to charge more. There is nothing bad about increased car battery voltage. If electrical devices of a car are functioning properly, within 5-10 minutes the voltage will decrease to its standard value of 13,5-14,0 V. In case the voltage doesn’t start to, gradually, decrease up to its standard rate, the overcharging of a car battery may occur. Consequently, a car battery will go on working on its highest operating abilities and there is a risk of the electrolyte being boiled away.
If the engine of a car is running and the voltage of the car battery is lower than 13,0-13,4 V, it means that the car battery is not charging. Still, even if you face this problem, you shouldn’t get to a maintenance center right away. Remember that before you start measuring the voltage of your car battery, it’s necessary to turn off all the devices that use electricity. Therefore, you need to turn off the headlamps, the air conditioner, the heating system and the car audio system. What should the voltage value of a car battery amount to when measuring it with the help of a multimeter? In case the electronic equipment is working properly, the voltage value should amount to from 13,5 to 14 V. If the value is lower, it means that the alternator of a car is not working. This is especially true if the voltage value is lower than 13,0 V when the engine of a car is running and all the electrical devices are turned off. One more reason for a low voltage value may have to do with the fact that the contacts of a car battery are corroded. For this reason, you need to check the contacts.
What are other ways to check how well a car’s alternator and car battery are working properly? There is one more way. The voltage value of a car battery amounts to 13,6 V when the engine of a car is running and all electrical devices are turned off. We need to turn on headlamp low beam. The voltage of your car battery should decrease a bit. It should decrease for 0,1-0,2 V. Then, you need to turn on the car’s audio system. After that, you turn on the air conditioner of your car and all the rest electrical devices one by one. Each time you turn on a different electrical device, the voltage of your car battery should decrease a bit. If it decreases significantly, it means that the alternator of your car doesn’t work on its highest operating capabilities and the alternator brushes are worn out. If all the electrical devices of your car are turned off, the voltage of your car battery shouldn’t be lower than 12,8-13,0 V. If it’s lower, your car battery is discharging fast and you need to buy a new one.
How to Check a Car Battery When the Engine of the Car Is Not Running
Here we also use a multimeter to check the voltage of your car battery. If the voltage is lower than 11,8-12,0 V, it means that your car battery is discharged. There is a possibility that you’ll be unable to start the engine of your car. Most likely, you’ll have to charge the car battery. A standard voltage value of a car battery if the engine of a car is not running should amount to 12,5-13,0 V.
There is an easy way to figure out the level of a car battery charge according to its voltage value. This method is time-proven. If the voltage value is 12,9 V, a battery is 90% charged. If the value is 12,5 V, a battery is 50% charged. If the voltage is 12,1 V, a battery is 10% charged. Irrespective of the fact that the method is considered to provide you with approximate values, it is quite efficient. There is a peculiarity you need to remember about when measuring the voltage of your car in case the engine is not running. The values may differ depending on when you measure the voltage. If you do it right after you switched off the engine of your car, the value you get may be different from the one you get if you measure the voltage the next morning. That’s why it’s better to measure the voltage before you are going to drive your car.
Based on the level of a car battery charge, you can see if your battery can keep the voltage rate for several days. In case your battery is totally discharged, the voltage won’t fall down significantly even if you haven’t used your car for more than a week. If your car battery is unable to keep the voltage rate, the voltage will fall down fast if your car battery is discharged.
Checking Your Car Battery With The Help of a Battery Load Tester
This method of checking a car battery is an efficient way to check the working capacity of a car battery. According to the results you get, you can see if your car battery is charged.
How do you check the level of your car battery charge? You need to connect a battery load tester to your car battery following the principles of polarity. The time of connection shouldn’t be more than 5 seconds. At first, the voltage value should be 12-13,0 V. When the time is out (5 seconds have passed), the voltage value should be higher than 10 V. Such like car battery is considered to be charged and able to operate when the load is high. If the voltage value is lower than 9 V, such like car battery is considered to be weak and untrustworthy. In this case, you’ll, probably, have to consider buying a new battery for your car.