It can be very frustrating when you discover one morning that your car refuses to start and you learn that the battery is dead. You can ask an expert mechanic to measure the battery’s voltage so that you can determine if the voltage is low and you will be needing a car battery replacement.
There is usually a chart for the range, so you will know how many volts does a car battery need to start. There are a variety of ways to measure the car battery voltage range. Here’s what you need to know.
Using A Multimeter
There are other maintenance-free batteries that have with them a charge indicator. You can find it on top of the battery, and it tells you if your battery is charged fully. You will see a green dot. When it needs to be charged, there will be no color.
And if the battery is faulty, you will see a yellow dot. Even if your battery comes with this indicator, you can still use a multimeter so you will know the general charge state of the battery.
Here are the steps to take when using the multimeter.
1. Set the voltmeter to 20DC volts.
2. Touch the black battery terminal which is the negative one with the black meter probe, also the negative one. Do the same with the positive terminal and meter probe. It is usually color red.
3. Ask someone to turn the headlights on so you can give the battery with a little bit of load.
4. Check the reading of the voltmeter.
Here are some of the things you have to take note of:
● A battery with a good charge will have a 12.5 or higher reading.
● At 75% charge, it will have a reading of around 12.3.
● At 25% charge, it will have a reading of 11.8 or even lower.
If you see that you have a low reading, put your battery to slow charge so you can improve the battery’s chemical reaction. You can then repeat the test. If the reading still does not go any higher, it may be time to consider replacing your battery.
There are other ways to check the voltage of the car battery. Now you may ask, how to check car battery without multimeter?
There are a variety of ways. Let’s take a look at some of them!
Open Circuit Voltage Test
The open circuit voltage test is done while the engine is off. You or the mechanic can use a dedicated battery tester for this test. You simply have to connect it to the terminals of the battery, and then you can read the voltage.
● A fully charged battery will have a reading of 12.65v to 12.77v.
● At 75% charge will have a reading of 12.45v to 12.54v.
● At 50% charge will have a reading of 12.24v to 12.29v.
● And at 25% charge will have a reading of 11.99v to 12.06v.
● With a reading of 11.75v to 11.89v, you have a dead battery.
Electrolyte Gravity Voltage Test
● With a 1.269 gravity reading, the battery is charged fully.
● With 1.229, it is 75% charged. With 1.194, it is 50% charged.
● With 1.159, it is 25% charged. A dead battery will have a 1.124 gravity reading.
These are just some of the tests you can perform to know the voltage of your car battery. Hopefully, this information will help you with the car battery voltage range so you know how fully charged or not your car battery is. Knowing this will help you in determining if you need to recharge your battery or if you need a new one.
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