The main purpose of a rechargeable car battery is to supply an electric current to the starter motor. It is a basic requirement to start ignition. The regular maintenance must include to check a car battery.
Inappropriate voltage, addicted to jump start, slow engine start are some of the common faults in a car battery. Today we shall discuss how to test car battery with a multimeter.
Check A Car Battery With A Multimeter
Most car owners do not check car battery until it fails. Voltage test at least twice per year is a preventive maintenance measure.
Multimeter
A multimeter is used to measure electronically volts, amepere and resistance. A properly used multimeter shows voltage information with accuracy.
Step-By-Step Guide
Below given steps can evaluate the true condition of car battery.
1. Wipe Out Grime
Locate the battery and wipe out any dirt or corrosion on the positive and negative terminals. The corrosion on terminals will not give true reading on the multimeter. These terminals are usually covered with caps, red for positive and black for negative.
2. Adjust Multimeter Settings
Multimeter has many settings / options. Don’t get confused. Just turn the dial to 20 volts. The true results will be obtained by removing all the surface charges.
3. Operating Voltages at Different Stages
The below given table clearly shows the must have voltages at different operations.
| Sr. No. | Stage / Operation | Voltages (Multimeter Reading) |
| 1 | Vehicle at rest | 12.2 Volts (Minimum) |
| 2 | Starting the ignition | 10.0 Volts (Should Not Drop below 10 Volts) |
| 3 | Running Vehicle | 14.0 Volts (At least) |
Do You Make These Mistakes And Car Battery Keeps Dying?
Check a Car Battery: Alternator Test
The multimeter readings are all remain within normal ranges and you are facing problems, there may be a fault in alternator. Overtime, due to different reasons alternator don’t work properly and struggle to maintain proper current. You can check it with below given simple technique.
Start your vehicle and turn on all the electronic gadgets such as headlights, interior lights, car stereo etc. It will put maximum load on your car battery. Attach multimeter’s red and black probe with positive and negative terminals of battery respectively. If the multimeter shows voltage below 13.5, your alternator is struggling to maintain. Its time to replace the alternator.
