How to Replace a Battery
Overview
How to know when to replace a car battery?
Assuming you haven’t left the headlights on and drained the battery, the first sign that you should replace a car battery is when the engine is slow to crank or won’t start at all. Dim headlights and warning lights on the dash could also be an indication. On visual inspection, severely corroded terminals or signs of the battery swelling are a sure sign the battery should be replaced. Finally, a voltage test can confirm your battery’s condition. Allow 30 minutes or more after running the car before you check this. Anything under 12.4 volts is cause for concern.
What do the numbers mean on a car battery?
The first significant number on a car battery is the group size. This number is the international standard for battery dimensions, terminal size, and polarity (terminal orientation). Essentially it is the part number. You’ll also see the cold cranking amps (CCA). Higher CCA means easier starting, bigger engines require higher CCA. You may also come across ‘reserve capacity’. This is the number of minutes the battery will supply 25 amps of power before running flat. Meaning that should your alternator fail; you can continue to run your car for about as many minutes as the reserve capacity states.
What battery does my car need?
What battery fits my car? You can find out with the my garage feature on the Supercheap Auto website. Simply enter your rego number or lookup your vehicle, search for car batteries; and you’re recommended the correct one for your car. You can also find battery specifications in your owner's manual, or you can take note of the battery group size (an international standard for battery dimensions, terminal size and polarity) and the cold cranking amps (CCA) and match these up with a new battery.
How long does a car battery last?
The life of a car battery can be as short as one year in the worst conditions, up to about 5 years or longer in the best conditions. Here are some factors which can reduce battery life:
How much is a car battery?
The increasing reliance on car batteries to power modern features means new batteries are no longer the cheap and simple devices they once were.
While you can still grab batteries for under $150, they are typically basic flooded lead acid batteries suitable only for older vehicles. Generally speaking, the larger the engine and more modern electronics; the more you will pay for a suitable new battery.
Paying for a battery with extra cold cranking amps and reserve capacity often comes hand in hand with a longer warranty as well.
How to change a car battery?
Before you jump into changing a car battery, you should take a look at specific instructions for your vehicle to ensure that the job is not outside your comfort and skillset. We will cover how to change a car battery according to the most common method.
Materials and Tools
Steps
How to replace a car battery
Review the process It’s a good idea to get familiar with your battery and the procedure in your workshop manual. If you don’t feel up to it, or you just CBF with DIY today, have a chat to the team at Supercheap Auto. We can probably do it FOR you. Certain high tech vehicles will require a professional to complete the battery change.
How to disconnect the car battery
Always ensure your vehicle is in gear or park with the park brake on and ignition switched off. Then you can pop the bonnet and get to work. Always remove the negative terminal first and be SUPER careful to keep your ratchet or spanner from contacting the positive terminal. If this occurs, the resulting spark will give you a scare at best, but the energy in a battery is capable of melting spanners and starting a fire. So again, be careful. Once the terminal is removed, it’s a good idea to wrap it with a rag and tuck it aside. Repeat this for the positive terminal.
How to remove a car battery
Examine the clamping system holding your battery in place. It may be a bracket over the top of the battery with two simple nuts on top which can be freed with a spanner. Other vehicles have a clamp holding the battery at the base. You’ll need the ratchet, socket and extension for these ones. Again if you’re not sure; refer to your workshop manual. Once the clamp is removed, plan your lift. Car batteries are SUPER heavy, so ensure you can position yourself for a safe lift, prepare a place to put it down, always keep the battery upright, and don’t be shy to ask for help.
Inspection and clean up
Whilst not essential (unless it’s REALLY filthy), this is a great chance to clean up the battery tray. Loosen up dirt and debris with a brush, then whisk it away with a vacuum. Check for corrosion around the battery tray while you’re here. If the battery terminals are looking heavily corroded; it might be worth looking at replacement. If there is just light corrosion and scale, use the battery terminal cleaner to remove this, then wipe them clean and apply a dab of battery terminal grease inside of each.
Replace the car battery
Remove the protective terminal covers from your new battery and slip a felt washer from your terminal protection kit over each terminal. You’re ready to lift that new battery in but as you do; ensure the posts are around the right way. You’ll see a plus symbol next to the positive terminal, and a dash symbol next to the negative terminal.
How to connect a car battery
First replace and tighten the battery clamp, and then set about refitting the terminals. Positive first, negative last. Take just as much care refitting these as you did removing them. Your new battery has way more kick than your sad old one.
Tips
Is it better to recharge a car battery or replace it?
If your battery accidentally runs flat, or shows low voltage and cold cranking amps; there is a chance that recharging the battery will get a little more life out of it. You can achieve this using an advanced battery charger with a ‘repair’ mode. However, if you continue to notice slow starting and a voltage and cranking test once again returns a poor result; you should replace a car battery.
Can I replace a car battery on my own, or do I need professional assistance?
Whether you can replace the battery in your car yourself or not comes down to a combination of your skills, confidence, and your particular vehicle. You will also need some basic hand tools. The best way to quickly decide if performing a battery replacement is for you is to read up on the procedure in your owners or workshop manual. If it seems a little out of your depth; give your local Supercheap Auto a call and we can usually fit a replacement car battery for you.
How to dispose of car batteries?
The easiest way to dispose of car batteries is to simply bring them down to Supercheap Auto where we offer car battery recycling for free! Your second best option is to take it to your council recycling facility. Car batteries should never be disposed of in your regular rubbish collection.
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