How To Check Your Car Battery


How To Check Your Car Battery

If you ever need to test your car battery just follow these easy steps whilst using a car battery tester and you can ensure that your car is running smoothly and be confident if you need to test a car battery again in the future.

A good tip to begin is to test your car battery roughly 12 hours after your engine was switched off. This ensures that your battery has settled and can provide a more accurate reading when testing.

The first step besides opening your car bonnet is to make sure that your engine is switched off before you begin. Wearing gloves would also be good advice to protect your hands from any chemicals when carry out the test.

Now its time to attach your car battery tester, your car battery tester will come with a guide to help you and you can refer to it if your unsure at any time during the test. Once you have attached the red lead to the positive terminal and the black lead to the negative one you should be ready to press start and begin the test.

A factor to consider is that temperature can affect the accuracy of the reading. The statistics here are based on a temperature between 20-22ºc so if when testing the temperature is different you can expect slightly altered readings. After pressing start a reading will appear a few moments later on the screen of your battery car tester, these numbers represent the voltage that is stored in your battery and the energy it has retained since it was last switched off.

A standard Sb/Sb 12V battery will have to following readings:

  • 12.65V states the battery is fully charged.
  • 11.89V means the battery is flat.

A maintenance free Ca/Ca or a VRLA 12V battery’s reading would be:

  • 12.77V represents a fully charged battery.
  • 11.75V is a dead battery.

The closer your readings are to the fully charged statistics the better condition your car battery will be in.

Check Your Car Battery Acid

Another possible test that can be carried out is to measure with a hydrometer to determine the levels of sulphuric acid in the car battery.  When purchasing a hydrometer it will have a book of instruction containing the readings to show what they mean and how to check your car battery levels safely. If you own a more up to date car it is more likely to have a built in hydrometer and will use a colour system to convey the readings of acid levels in the battery.

  • RED representing the battery should be replaced.
  • YELLOW to represent the battery may need maintenance performed.
  • GREEN stating that the levels are good.

If the test should fail then you will need to replace your car battery as soon as possible. If you wish to remove the battery yourself this is possible however do take care as a simple miss connecting of wires could affect the electrical system for the entire vehicle and also don’t forget the battery contains very dangerous acids as well. If you are unsure on anything the better option would make an appointment to see one of our skilled mechanics, that way you can ensure the process is carried out correctly. Most garages will know exactly what to do with the dead battery as well so you wont have the trouble of trying to dispose of it in a safe and secure way.

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