While most people understand that car batteries are 12-volt DC batteries, there’s a lot more to consider than just that. Car batteries actually have a voltage range, which affects its performance and lifespan. A car battery voltage range test is often the key to finding out all the necessary details about your battery’s overall condition.
By comparing your car battery’s voltage measurements with the normal battery voltage range for that specific type of battery, you can determine the current state of your battery and learn more about the charging system, how likely it is to fail, and how important it might be to have it replaced.
Taking a Voltage Reading
A voltage reading involves measuring your car’s specific voltage at any given time and comparing it with past results to find out whether or not the battery might be dying. The voltage range can be measured easily with a voltmeter. Set the meter to a maximum value above 12-15 volts and touch the positive cable of the voltmeter to the positive terminal of the battery, and the negative cable of the meter to the negative terminal. If you get a negative voltage reading, that means you’ve swapped the leads on the multimeter. Swap them back to get an accurate reading.
The Ideal Car Battery Voltage
Measuring your car battery’s voltage can help you determine how charged your battery is. A perfect voltage with the engine running is between 13.7 and 14.7V. With the engine off, it should be 12.6 volts. If the battery isn’t fully charged, it will diminish to 12.4V at 75%, 12V when it’s only operating at 25%, and down to 11.9V when it’s completely discharged.
Load Tests
Measuring voltage tells you about the charge of the battery, but it is not an accurate indicator of the health of the battery. Your battery may have a low charge but still be in healthy condition. To determine a battery’s health, you need to do a load test. A load tester determines the voltage generated by the battery while a load is placed on the battery. That value will be lower than the standalone voltage test.
When performing a load test, you should apply a load to a fully charged battery for 30 seconds or less. The voltage should not drop below 9.6V. If your battery measures less than 12V on a regular basis during voltage tests and it failed the load test, it may need to be replaced. This generally needs to happen every five years or so on average anyway.
Safety Tips When Doing a Load Test
Auto professionals can help you conduct a load test as they can be dangerous to do on your own and load testers are specialised pieces of equipment. If you plan to load test your battery on your own, ensure you
- Always wear safety glasses when dealing with batteries
- Don’t smoke around batteries
- Inspect your battery for signs of wear and tear before testing it
- If you see a build-up of corrosion, clean it off with a mixture of baking soda and water.
If you smell sulphur (rotten egg smell), consider letting a professional handle your battery.
Contact Car Care Joondalup for Expert Servicing and Repairs
For any and all auto repairs and servicing including battery testing and replacements, our expert Joondalup mechanics can help. Call the team at Car care Joondalup on (08) 9300 9796 or contact us online today.
