Power Check 101 – 3 Ways to Test a Car Battery

Power Check 101 – 3 Ways to Test a Car Battery
The car battery is the powerhouse that kickstarts the engine and supplies electricity to a different crucial component, from lights to infotainment systems.
But as with any other critical car component, car batteries can age, weaken, and eventually – lead to unexpected and potentially highly pricey breakdowns. Not if you know how to regularly run a check-up test.
Let’s explore the 3 ways you can test your car battery before it dies on you in the most unfortunate situation.  

Understanding car batteries 

Before we go hands deep into the technical test, let’s first cover some essentials. A car battery is a rechargeable device that stores and supplies electrical energy to power a vehicle's electrical components.
It’s made of alternating lead plates, known as positive and negative plates, which are covered in an electrolyte solution typically composed of distilled water and sulfuric acid.
When the engine starts, the battery releases stored energy to turn the engine's crankshaft, and while the engine runs – the alternator recharges the battery.
Proper maintenance, including checking and cleaning terminals for corrosion and ensuring adequate electrolyte levels is crucial for the battery's lifespan which is usually around 3 to 5 years on average.  

How do car batteries work? 

Car batteries work by storing and supplying electrical energy to power a vehicle's electrical components. When the engine is off, the battery stores electrical energy through chemical reactions between the lead plates and electrolytes.
So, when the ignition is turned on, the stored energy is released, providing power to the starter motor. This makes the engine’s crankshaft turn, initiating the combustion process.  
As the engine runs, the alternator takes over, generating electricity and recharging the battery. This continuous cycle of charging and discharging provides a steady supply of electricity to car systems like lights, radio, air conditioning, and more.
Proper maintenance and care are essential to prolong the battery's life and maintain its reliable performance. 

What are the main car battery malfunction signs? 

Since a car battery’s average lifespan is from 3 to 5 years, there will be inevitable signs of wearability that could signal that it may be time for a replacement: 
  • Difficulty starting the engine – if the engine takes struggles to start, it could be a sign that the battery's starting power has reduced. 
  • Weakened electrical component performance – dim headlights, sluggish power windows, and even slow response from the radio. 
  • Warning lights – dashboard may display battery light or check engine light
  • Corrosion and build-up on terminals – visible corrosion or a white, powdery substance on the battery terminals can hinder proper electrical connections. 
  • Low fluid levels (if a car battery has removable caps) – can affect the battery's performance. 
  • Swelling or bulging case – physical damage or swelling of the battery case indicates internal issues and a potential safety hazard. 
  • Frequent jump starts – may indicate a failing battery or a problem with the charging system. 
  • Age – if your battery is more than 3 to 5 years old, it’s definitely time for a new battery even if there weren’t any issues with its performance.  
If you notice any of these signs, you should get your car battery tested by a professional mechanic to determine its health as soon as possible. Regular maintenance and battery checks can help prolong the battery's life and help avoid unpleasant stops on the road. 


How to test a car battery? 

You can perform battery tests yourself if you can’t see your mechanic just yet, or already have some experiencing working on your car. One sure way of checking would be to simply inspect your car battery’s temperature – a malfunctioning battery will heat up momentarily, making it difficult to even lay a hand on.  
But besides this quick check, in this section, we’ll go over 3 different tests that could help you determine the state of your car battery.  
Test 1: with no equipment 
One of the easiest ways to tell whether there’s something wrong with your vehicle’s battery is to perform a load test which won’t require any equipment. Since car batteries are responsible for supplying electrical current to other vehicle components, the load test will involve observing one component – like headlights. Just note that this method will only work with halogen lamps. 
Step 1: Make sure your engine is turned off. Once that’s done, turn on your headlights. 
Step 2: Leave the headlights on for at least 10 minutes.  
Step 3: Once the time has passed, start your car.  
Look at the brightness of your headlights. If they visibly dim as the engine starts, that’s a good indicator that the battery isn’t operating at full capacity and thus fails the load test. This is because on average a car battery should be able to hold charge for at least 10-15 minutes.  
Test 2: with a multimeter 
Testing a car battery with a multimeter is a relatively straightforward process. Before testing the battery, make sure to wear safety gloves and eye protection. Car batteries contain corrosive chemicals and can produce flammable gases, so take necessary precautions. 
Step 1: Park your car in a well-ventilated area and turn it off completely.  
Step 2: Open the car's hood and locate the battery. It's usually a rectangular-shaped box with two terminals (positive and negative). 
Step 3: Turn on the multimeter and set it to measure DC voltage. Choose a voltage range that can handle at least 15V to ensure accuracy (for newer models you should look for 20V). Fun fact, some luxury class models or trucks can even handle up to 24V. 
Step 4: Connect the multimeter’s positive (red) lead to the positive terminal of the battery, and then connect the negative (black) lead to the negative terminal of the battery. 
A fully charged battery should read around 12.6 to 12.8 volts. If it reads lower than 12.4 volts, it may need charging. However, If the voltage is significantly lower (below 12 volts), the battery may be discharged and in need of recharging or replacement.  
Test 3: with OBDeleven 
Finally, if you own the OBDeleven, you can view your battery status with the Battery Status feature. With it, you’ll always know your battery’s performance and overall health.
The feature keeps track of charging, discharging, voltage, and it will also show the color status indicator which indicates the overall health of your battery, notifying you when the battery must be charged.
The best part of this feature is that you can quickly check the battery status straight from the mobile app’s home screen.  

Summing up 

Performing basic car maintenance tasks can help track your vehicle’s help and understand better how it functions overall. That’s why regularly testing your car battery can save you from unexpected breakdowns and inconveniences.
By following these 3 simple methods of testing a car battery outlined in this blog post, you can gain valuable insights into your battery's health. Just remember that if you're unsure about the test results or encounter any issues during the testing process – consult a professional mechanic for further assistance. 
Disclaimer: Advice, how-to guides, and car care tips on our blog are intended as helpful resources for general maintenance and repairs. While we strive for accuracy, the information is provided to the best of our knowledge and should be used at your own discretion and risk.

Always refer to your vehicle's owner's manual or consult a certified mechanic for specific repair details and safety procedures.