December 12, 2022 / by Danny Mavis

4x4ers who frequent the Australian outback and wilderness need a more sophisticated battery setup than those who stick to the tarmac. If you’re into exploring the remotest and most pristine places in Australia, a capable battery that will reliably power all of your 12V accessories is essential to making your trip more convenient and more like home. You don’t want to drain your starter battery and get stuck in the middle of nowhere, which is why most 4x4ers get a 4wd battery dedicated to powering your fridges, lighting, charging docks, etc.

These batteries are known as deep-cycle batteries, and they can be charged and discharged for many cycles before they start deteriorating in quality and performance. Moreover, they provide consistent power for long times rather than strong, short bursts. These batteries come in a wide range of types and sizes. Before I get into the different types, it’s important to make sure the battery you choose is capable of handling the under-bonnet temperatures, repeated impact and vibration from driving through rough terrain.

4WD Battery Chemistry

Lead-Acid Batteries

Lead-acid batteries feature lead pasted to a plate inside the battery housing and are immersed in an electrolyte that’s a mix of water and sulphuric acid. There are two basic types of lead-acid batteries available – low-maintenance batteries that allow you to top up the battery fluid, and sealed, maintenance-free batteries that come sealed in a container, where you can’t top off the fluid.

4wd batteries

AGM Batteries

AGM batteries, also known as absorbed glass mat batteries have the electrolyte solution absorbed into glass mat microfibers compressed against the plate. This means the electrolyte isn’t loose, and these batteries are the preferred option for 4WDs, as there is no chance of leakage. 

Gel Batteries

Gel batteries, as their name implies, have the electrolyte solution immobilised inside silica – a chemical agent that adheres to the battery. As a result, you get a spill-free battery that can be used in rough environments.

Lithium Batteries

Lithium batteries are lighter in weight, allow for faster charging and are the longest-lasting batteries available today. They’re suitable for heavy-duty use, and while you can expect to pay a premium price for them, the fact that they’re long-lasting means that they’ll turn out to be the more valuable alternative in the long run.

car batteries

Dual Battery Setups

While you don’t necessarily have to run two batteries for every application, it can make things much easier. By using the starter battery together with the deep cycle battery, you’ll make sure you never wake up to warm beverages or a flat starter in the morning. A dual battery setup will basically allow you to use all of your appliances without straining your starter battery. Even if your starter battery runs flat, you can use the auxiliary battery to charge it back up.

That being said, how much electrical charge a battery has will play a huge role. For the average weekend warrior, a deep cycle battery with up to 100amp/h will suffice. Someone who will stay on a weeklong trip, on the other hand, may need a 200amp/h battery.

4×4 Batteries and Solar Panels

Having the ability to get power from the sun can go a long way in extending the capabilities of your batteries and stay off the grid for as much as you want. Solar panels for 4x4s can be a great investment, although a costly one. For a 100 amp/h batter, 120-watt panels and a quality regulator will allow you to run everything you need for a couple of days, at least. Solar systems for 4×4 are becoming increasingly popular due to the increasing restrictions on the use of power generators.

cars battery

Smart Battery Chargers

An empty battery is no good, and neither is an overcharged one, as it will significantly decrease its lifespan. To ensure neither of that happens, you’ll want a 12V DC Smart Charger, or a 240V AC one, that comes with the right voltage and amperage. The right voltage and amperage mean the charger should match the chemistry of the unit, state of charge and internal resistance. Using the wrong charger can void your battery’s warranty, and cause it to malfunction.

What to Look for?

It’s important to buy 4WD batteries and accessories designed, manufactured and tested in Australia, to ensure they’re capable of withstanding Australia’s harsh conditions. Vibration and heat are the biggest enemies of 4WD batteries, and if you venture off the beaten trail, there’s plenty of both those things. That being said, you might want to consider paying extra for a battery made of solid internal parts, and one that can withstand the stress placed on its plate system. Quality-made batteries that last the most cycles will cost more, but you’ll eventually get more out of them, making them a well-worth investment in the long run. As long as you understand your power demands, you’ll have an easy time finding a suitable battery.