Aaron Widmar
No Comments

Change a Car Battery in 8 Simple Steps

Decrease Font Size Increase Font Size Text Size Print This Page

A simple DIY guide to replacing your dead car battery with a new one at home

Changing a dead car battery by loosening terminal bolt with a wrench
Photo: The News Wheel

It’s important to properly care for your car’s battery. If you don’t, you’re going to wake up to a dead battery and a car that won’t start. If that happens to you, here’s how you can quickly replace the old battery with a new one.

Overdue on Vehicle Maintenance? Make sure you’re following this recommended service schedule for your car

Step 1: Confirm the battery is dead

Before taking all the time and money to replace the battery, make sure it’s actually kaput. The cables might have wiggled loose from the terminals and need tightening. Or, a quick jump or overnight recharge might be enough to bring the voltage back up.

The easiest way to determine this is use a voltmeter (as explained here) as see if the battery can be revived. However, if your battery is pretty old or corroded, it’s probably not salvageable.

Step 2: Purchase a new battery

If your car is dead, you’ll need to hitch a ride from a friend or relative to the store to buy a new car battery. You can shop for one at an auto parts store or a big box store like Walmart or Costco. If you buy a new battery at some of these places, they might even install it for you.

It’s important that you purchase the correct battery size, which is categorized into “group sizes.” Check the old battery and see what category it is (it might be something like 75, H6, or 96R) and then double-check that category against what a couple online sizing guides prescribe.

You can also determine the group size by consulting the huge book in the store’s battery aisle. Search for your car by make, model, year, and engine, and it will tell you which item to purchase.

Note: If the old battery is still under warranty, pursue this option first before spending money on a replacement.

Step 3: Gather your tools & prep your car

Park your car somewhere safe away from traffic like a driveway, parking lot, or garage. Engage the emergency brake and turn the engine off. Wear work clothes and protective rubber gloves in case you get corrosion or acid stains on you.

Grab a wrench, a flashlight, and a magnet (in case you drop small parts). Pop open the hood.

Detaching cable from dead car battery
Photo: The News Wheel

Step 4: Detach the old battery

Use a wrench to loosen the attachments anchoring the cables to the battery. You should always start by detaching the negative (black) cable first, which should have a huge (—) by it. Pull the cable end away from the battery so it isn’t touching the terminal anymore.

Then, detach the positive (red) cable, also lifting that cable away.

Removing old battery unit by slowly lifting
Photo: The News Wheel

Step 5: Remove the old battery

Give the battery a gentle tug. If it doesn’t move, that means it’s anchored in place. Shine a light down to the base of the battery and see if there’s another bolt clamping it in place. If so, you’ll need a long wrench to loosen that bolt too.

With both hands, slowly lift the battery out of the engine bay and set it somewhere safe on the ground. Anticipate that the battery will be very heavy, so try to retain control and not knock it around.

Step 6: Clean the connectors

Before you proceed with installing the new battery, take a minute to clean off the connectors.

Mix a teaspoon of baking soda into a cup of lukewarm water and immediately use a toothbrush to scrub the solution onto the metal connectors. Wipe the piece thoroughly with a rag to remove all residue and rinse them with a little water, wiping them dry.

You can follow the steps in more detail here as explained by It Still Runs.

Installing new car battery in engine
Photo: The News Wheel

Step 7: Insert & attach the new battery

Repeat everything you did in steps 4-5 in reverse, carefully lowering the new battery in place, resecuring the base, reattaching the red cable, and reattaching the black cable last. Make sure they’re good and tight so they don’t come loose when you’re driving and cause your car to stall.

Step 8: Return the old battery

When you purchased your new battery, you were probably charged a core fee. To get this expense reimbursed, you’ll need to take the old battery back to the store. Contact the returns/customer service desk with the receipt and reimbursement slip that came with the receipt. You’ll hand off the dead battery in exchange for a refund of the fee, and the store will ensure the battery is properly recycled.

While there are many maintenance tasks you should always pay a service expert to perform for you, changing a car battery is simple enough to do on your own in your driveway. If you’re unsure if you should replace the battery yourself or pay someone else to do it, here’s a helpful list of pros/cons exploring each option.

Not Driving Your Car Frequently? Make sure you’re still properly caring for it in these ways