Car Advice

How to change a car battery

The battery in your car can and will go flat and, as Murphy’s Law dictates, when it’s most inconvenient for you. Here’s how to change a car battery.

AND THAT’S EXACTLY what happened to me this week. I knew the battery was beginning to fail as there was hesitation beginning to creep in during ignition. Meaning, you could hear a whirr, whirr, catch before the engine fired.

It’s winter now and I live in the Blue Mountains, right up at the very top too, and the nights up here are very cold. Very cold. And nothing kills a car battery quicker than the cold… that said, mine hasn’t been changed since new, and it’s now seven years old and that’s an excellent innings for a car battery. When I said nothing will kill a battery quicker than cold, well, nothing except for heat as this aids in moisture evaporation and your car’s battery contains around 2-3 litres of fluid.

Anyway, earlier this week I went to start the car and… nothing. No lights, nothing, just a clicking. Dead battery. Never one to miss an opportunity to demonstrate an easy home DIY car maintenance tip, I figured changing a car battery would be a nice easy one that you should all know how to do. It literally took me 30min and that included a drive to my local car parts retailer to buy the battery.

Now, you might not, like me, have to replace your battery even if it’s flat. But, mine was old and I figured replacing it was the best way to go. If you’ve got a maintenance-free battery and this usually means it has a larger fluid reservoir to deal with fluid loss in hotter climates, among other things, then you can recharge the battery using a multi-stage battery charger. But we’ll deal with battery maintenance and charging in another article, or two. This article only deals with the physical replacement of a battery.

It’s worth noting that if you’re not comfortable in replacing your car’s battery then call your local motoring club and their breakdown service (NRMA, RACV, RAA, RACQ, etc) or auto electrician.

I’ve had a look at quite a few battery-changing articles over the years and they all fail to mention one thing, well, some fail to mention more than one thing, but there’s one universal point that’s always failed to be mentioned, and that is what you need to know once you’ve replaced the battery and have started your car for the first time. And then, what do you do with the battery once you’ve removed it from your car, because you can’t just dump it in the bin.

What will I need?

  • Good-quality leather gloves;
  • Goggles;
  • Vapour-resistant mask; and
  • Socket set with extensions.


The car won’t start. You’ll know the battery has gone because your engine won’t fire when the key is turned or the starter button pressed and your dashboard will illuminate briefly and then the lights will go out once you’ve released the starter button or turned the key back to its starting position. You might hear a clicking sound, too when you’re trying to start the car. It’s worth noting that the battery won’t just have been fine one day and dead the next, so pay attention to your car, you’ll have likely noticed the ignition procedure sounding and feeling a little lethargic as the battery is beginning to give up. It’s worth considering replacing at that point rather than waiting for it to fail completely but, if it has failed, here’s what to do…

Replacement battery. You’ll want to head out and buy a replacement battery before taking the old one out of your car. Grab your owner’s handbook and flick to the page about the battery, it’ll usually describe the type of battery you have. If that’s a little confusing, then take a photo of the top of your battery and take that down to your local auto accessories or battery supplier, give them the make and model and age of your car and then they’ll be able to recommend a battery to suit. The replacement battery I purchased, cost me $242.00 but prices usually start from $95.

The battery in your car can and will go flat and as Murphy’s Law dictates, when it’s most inconvenient for you. Here's how to change a car battery.
This is the photo of my old car battery which I took to show the auto accessories shop to help out with selecting the correct replacement battery. You’ll notice it sits inside a nice little soft case; if yours does too then don’t throw that away put it back over the new battery.

Disconnecting the battery. Once you’ve got your replacement battery and the tools you’ll need, see above for list, then making sure the keys are removed from your ignition and the car is parked on level ground, or as close to level as you can get. Your owner’s handbook will likely describe the process for replacing the battery which, once you’re wearing gloves, is to remove the cable and clamp from negative terminal first. Your new battery will likely have little plastic terminal covers; it’s worth using them to pop onto the terminals of the old battery while you’re removing it. Once you’ve removed the negative cable have a quick look at the clamp; it’s worth sticking one of your gloved fingers into the clamp to give it a quick clean and then you might need to tie the cable back or tuck it out of the way. After removing the negative cable, you’ll be able to remove the positive.

how to change a car battery.

how to change a car battery.

Removing the battery. Once the cables have been removed and are tucked out of the way, you’ll likely need to have a look at unclamping your battery from its base, this is where a socket set with extension pieces will come in handy. Once you’ve removed the clamp which keeps the battery from rocking around while driving, you’ll be able to carefully lift the battery out of the car and onto the ground. Then remove the terminal caps, one at a time, and place them onto the new battery. Be careful when removing the battery as battery acid, as the name suggests, is corrosive and can sometimes spill out of vents in the battery.

how to change a car battery.

Installing the new battery. This is the reverse of what you’ve just done. Place the battery back into its holder, making sure the positive and negative terminals are facing the correct direction, and then reinstall the clamp or strap used to hold the battery in place. Once you’ve done this check the battery is tightly in position and can’t be rocked.

how to change a car battery.

Positive and Negative. This too is the reverse of the original process in that you fit and tighten the Positive terminal first and then move to the Negative terminal. You’ll want to make sure the cable clamps have been seated correctly on the terminal and that they’ve been tightened nice and snugly.

how to change a car battery.

Starting the vehicle. Once you’ve removed the battery and started the car for the first time you’ll likely notice the ESP or stability control warning light is illuminated on your dashboard. Don’t panic. And, this is why it pays to read the owner’s manual, this warning light illuminating is normal and it will extinguish once you’ve driven a couple of metres. However, if it stays illuminated for your entire journey then a trip to your mechanic will be in order. It’s worth remembering that your new battery is unlikely to give the longevity of the original, manufacturer-fit item.

Disposing of the battery. You can’t just dump your car’s old battery into your wheelie bin. Batteries contain corrosive substances and are combustible. Your local Council-run refuse and recycling centre will dispose of your old car battery, so, check your local Council’s website for the location of the centre nearest to you, it will also explain how you should package the battery for disposal. Car batteries are 98% recyclable and if your local council won’t take your old battery then check with the place you purchased your new one from, they’ll either take the old battery and have it recycled or know who will. Or, you can always follow this Planet Ark link to locate your nearest battery disposal location.

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6 years ago

Ok, that works for older vehicles. The modern PC on wheels does make you work a little more. Never remove the terminals from the battery if you don’t have an alternative power source clamped to the terminals. It can be a motor bike battery with crocodile clamps or 10 Amp wires from the new battery to keep the computer happy. If you don’t , you will have lots of programing to do .As most of us does not have diagnostic tools ,it means off to the service center. Now how do you get it there? $$$$$

6 years ago

There is one thing that you forgot, the ECU. Before removing the terminals, get some crocodile clamps and some 4 mm electric wire and connect to the terminal from the new battery, so some power is maintained to keep the ECU alive.That way you don’t have to worry about warning lights coming on, and the ECU will keep all the original settings. ECU is a sensitive little bugger. As one of my drivers once pointed out while servicing a JCB back hoe. If you close the nose, how can it breath.

Isaac Bober

Isaac Bober