Is your car a bit slow to start in the morning? Or have you noticed that your battery keeps going flat? If this is the case then you may need to look at testing your car battery.
If you have a multimeter you can carry out a battery test in the comfort of your own home. A multimeter is an electronic instrument that measures voltage, current and resistance. If you’re looking for accurate results then we’d advise testing your battery when it’s cold, preferably in the morning when the car has been left overnight.
Unfortunately, a lot of people don’t know how they would go about testing a car battery, and all the important information that you need to begin.
How Many Volts Are In A Healthy Car Battery?
It’s important to understand the data provided from your multimeter, so you know whether your battery is strong and healthy or if it needs to be replaced. A minimum of 12.6 volts should be held in a healthy battery, anything less than this means that there is an issue with the battery.
How To Conduct A Car Battery Test
You will be able to find the battery underneath the bonnet of your car, next to the engine, if you’re struggling to find this then you should use your owner’s manual for further guidance. When you test the battery, you need to make sure you have access to the two terminals on the top. The black one that’s marked with a ‘-’ is the negative terminal and the red one marked with a ‘+’ is the positive terminal. You may find one or both of these located under a hinged or sliding cover.
Note: When the battery is exposed, make sure you’re careful not to rest any metal tools on the terminals.
The measurement you need to focus on is the DC (direct current) voltage, this is usually a solid line and a dashed line above the letter V on the multimeter. Set the dial to 20 to measure 0-20 volts on the multimeter. Then to get a reading, hold the red probe to the (+) positive terminal and the black probe to the (-) negative terminal.
If you notice the reading displays a minus (-) before it then this means the probes are connected to the wrong terminals and need swapping around. As soon as these are connected correctly, the voltage of a rested battery should read above 12.6V.
A battery that is only 50% charged will display a reading of 12.2V, and a reading of 12V means your battery is considered to be fully discharged or ‘flat’ and should be recharged as soon as possible.