Here are 8 steps to check your car's battery health at home.

Voltmeters are used to measure the voltage of devices. You have two options for voltmeters: an analog one or a digital version. It all depends on what you like and your budget. Turn off any accessories in your car that may drain the battery's power. Turn off your car's ignition and radio as well as the headlights.
The covers should be removed from the battery terminals. Next, remove the covers from the battery terminals. Connect the positive end of the voltagemeter to the red terminal. The negative should go to the black one. The voltage should be between 12.4V and 12.7V.
If your battery's voltage is above 12.5V, it is considered a healthy battery. However, if the battery is 7.5% full, your battery will be at least 12.3V. If your battery's voltage is below 11.8 V, it means that the battery has low charge. It will work at 25%. However, voltmeters are not always the best way to get accurate results. It is better to load test the battery.

If you do not have a voltmeter, you can check how the car’s headlights react when you turn the car up. Your car's battery could be at risk if the headlights are dimmer than normal. Your alternator may not be charging the battery fully if the car is turned up.
If you don’t notice any change in the brightness of the headlights when you turn the car up, the battery is working properly.

The indicator is a modern component. This indicator attaches to the battery and moves when the ignition is turned on. An arrow will turn red or green depending on whether the voltage of the battery is low. If your battery voltage is too low it will turn red. When it's in good shape it will turn green. You will notice a black hue when your battery is dead and not in use.

You will need to use a car battery tester for this purpose. Use a CCA rating one-half to test the battery and then observe for fifteen seconds if it holds 9.6V. Make sure that the battery has been fully charged prior to performing the test.

A performance certificate can be used to check the car's battery if you don't have a voltagemeter. You tap the tip of the power measuring probe on both the positive and negative battery poles. The reading of a good battery should be between 12.2 and 12.9 Volts.
You must ensure that the ignition has been turned off and that all battery-powered accessories have been turned off. However, this is not the best method to measure as you can test it under load.

An ammeter can be used to measure the current and future battery charge. You can see if the alternator has charged your battery fully by using an ammeter. Your battery is considered OK if the current charge is fully charged.

To check acidity of the batteries plates, the hydrometer can be used. A weak acid indicates that the battery is functioning correctly. Buy a combination hydrometer and thermometer for the best results. Some models can adjust automatically, others have a conversion chart.
You should always wear gloves when handling acidic battery acid. You should not use an electrolyte thermometer to determine the temperature of the solution because it can react with acid.
Open the plates on top of your battery. Put your hydrometer inside the first battery cell. The electrolyte will flow into your hydrometer as soon as the lid is lifted.
Take note of what the electrolyte's specific gravity was at the time. You can repeat the experiment with other cells.
If the reading is between 1.265-1.299, it's a functioning battery. Low readings indicate an undercharged one. If the measurements are not consistent, the battery may be sulfated.

To detect cracks in the battery, a physical inspection is necessary. First, disconnect the battery terminals. Then remove the battery. Check that the surface of your battery is flat. Overcharging can cause the battery to become drained. You should inspect the battery terminals, and check the insulation. Replace the battery immediately if there are cracks.
You must first clean the battery before you place it back into the carrier. It is very easy to clean the battery. You will need some baking soda and water, as well as a soft toothbrush. Put the contents in a bowl and use the soft brush to clean the sides and top of the battery. Use a damp cloth to remove any liquid. Continue the process with the connectors.
Verify that there is no corrosion on the battery carrier. Screw the clean battery into the compartment. The battery should not move in any direction. You should replace all terminals starting at the positive ones. To prevent corrosion, apply Vaseline/Grace to the poles prior to closing the cover.