FAQ: When and how to change a car battery

It’s one of the most commonly asked questions when it comes to car care – how and when do you change the battery? Ken, an engineer at EnerSys, shares his expertise.

Equipment Needed:

  • Safety glasses
  • Rubber or latex gloves
  • Wrenches
  • Sockets with extensions and driver
  • Baking soda
  • Brush
  • Water
  • Rust proof spray paint

When do I need to replace my car battery?
Traditional flooded batteries – when chemically healthy – work quite well. When a battery reaches the end of its life, the vehicle does not crank.  If you know you haven’t left an electrical item on, immediately replace the battery as it has reached end of life. Also, if the crank slows suddenly then resumes to normal, replace the battery if it is 4 years or older.

Are there any warning signs?31-800_thick_right
When there is a sudden failure to crank or sudden slow cranking.

How do I test the battery?
Car dealers, auto parts stores and battery distributors use various battery testers to determine tested Cold Cranking Amps (CCA) against published ratings. If the tested value is less than 80% of specified CCA, I recommend replacing the battery.

What’s the proper way to take the old one out?
Wear safety glasses and rubber or latex gloves. Remove the negative battery cable and then the positive cable. Loosen and remove the lower battery hold down bolt and wedge or top battery hold down bracket. Take battery out of the car. Reverse this process to install the new battery.

How should I clean the compartment?
Clean with a mixture of baking soda and warm water. When first applied to the battery compartment, the mixture will foam indicating the presence of battery acid. Keep applying the mixture until the foaming action has stopped – this indicates all acid has been neutralized.  Rinse the area with clean water. Any bare metal should be repainted with a rust proof spray paint.

How do I install the new battery? Is there an order to how things are attached?
Install the battery, then reinstall the battery hold down bracket or lower wedge and bolt.  Make sure on the lower hold down the battery lower hold down lip is secure into the battery tray hold down lip.  Install the positive cable and then the negative.  On ODYSSEY® batteries it is not recommended to use any anti-corrosive red spray on the battery terminals or cable connectors.

What should I do with the old battery?
The old battery has a recycle value. Take it with you to turn in when getting your new battery; otherwise you will likely pay a core charge (kind of like the deposit you might make for a bottle of soda – you receive a refund when you bring back the recyclable). Your old battery can be taken to any auto parts store, battery distributor or dealer.

Always be sure to follow the manufacturer’s guidelines for battery care and handling, and direct any questions to your battery professional.

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