Checking Car Battery Voltage
Testing a battery with a multimeter is a simple process.
Checking car battery voltage. Battery voltage readings are as follows. To get a true voltage reading of the cars battery it is important to measure the voltage after the car has been sat for a period with the engine off preferably overnight this provides you with the car battery open circuit voltage or also know as the resting voltage. It s important to test your battery and electrical system regularly not just when it s starting to show signs of weakness. To check a car battery turn off the ignition and pop your vehicle s hood.
Before you do this test yourmechanic will test the car battery to be sure that it has at least a 75 charge. Battery voltage will change 01 volts for every 10 degree change in. The resting voltage should ideally be no lower than 12 6v. This type of car battery test measures the ability of the battery to produce current.
Then the voltage of the battery is measured under a load similar to what it takes to start your car. 12 volts is the standard automotive battery in today s vehicle and each of the battery has 6 cells with a voltage of 2 1. If the battery is in good condition the voltage will read between 12 4 and 12 7 volts. Set the dial to 20 which will allow you to accurately measure between 0 20 volts.
Hook up a voltmeter to the car s battery by connecting the red lead to the positive terminal and the black lead to the negative terminal. How to check a car battery with a multimeter. When a car drops for instance from 12 6 to 12 0 there will be 75 difference. A fully charged car battery has 12 6 volts.
At about 80 degrees a fully charged battery will be around 12 5 12 6 volts. How to check car battery with multimeter. Car battery testing voltage. To be more specific.
Check the voltage reading on your screen. The first test with your multimeter will measure dc voltage indicated with a solid line and a dashed line above a letter v. The first thing to do is make sure you can access the two terminals on the top of the battery. 12 66 volts 100 charged.
Bear in mind that when a battery goes down to 12 2v it s actually only 50 charged. Proactively testing it or making sure your mechanic does twice a year will help reduce your chances of failure. Touch the red probe to the positive terminal and the black probe to the negative terminal. 12 45 volts 75 charged.
12 06 volts 25 charged. These readings are for a battery at 80 degrees fahrenheit. There is a very big difference when a car battery drops even a small amount of voltage. A fully charged car battery voltage should be 12 6v or above this is with the engine off.
A fully charged battery ideally measures at 12 66 volts and above but 12 6 volts at 80 degrees 12 588 degrees at 30 degrees and 12 516 volts at 0 degrees are. Most retailers offer a simple free five minute battery test.