Can deep cycle batteries be used in cars?

With so many models and types of cars available on the market today, it can be a little overwhelming to figure out the best type of battery for your vehicle. Caravans, recreational vehicles, sedans, camper trailers, utes and 4WDs all run different systems and have different power requirements. Putting the incorrect battery in your vehicle can do more damage than good, so it’s important to know what type of battery your vehicle needs before you install it and potentially affect the different components of your vehicle.

What is a deep cycle battery?

A deep cycle battery differs from a conventional car battery in several ways. The concept of a deep cycle battery is to provide a low to medium current over a long period of time whilst a car battery is designed to provide a surge of power to start a vehicle.

This is why deep cycle batteries are often used in marine applications, caravans, camper trailers, and off-grid solar systems as they’re very energy efficient and store power very well. Their ability to provide power over extended periods of time means your lights, fridges and other electric elements have a constant power source.

If you were to hook up a car battery and use it for something that’s designed to be powered by a deep cycle battery, the car battery will drain quickly and be useless in no time at all.

Can a deep cycle battery be used as a car battery?

The answer to this question is that technically yes you can, but you shouldn’t. Just like you can use sand instead of sugar for your morning coffee or drive a screw in with a hammer, just because you can, doesn’t mean you should.

Whilst technically deep cycle batteries will provide enough power to start your vehicle, this is not its intended use and over time this will drain your battery faster and cause potential damage to your vehicle.

The other thing to consider is that deep cycle batteries are quite sensitive to heat, therefore aren’t the best solution for under the hood of a vehicle where it can become extremely hot – particularly in Australian summer conditions.

So our answer to this question is NO - a deep cycle battery should NOT be used as a replacement for a car battery.

If you use a deep cycle battery in your car, it’s very likely you will:-

  • Shorten the lifespan of your battery
  • Damage the electrics in your vehicle
  • Shorten the lifespan of the electrics in your vehicle
  • Potentially void any warranty claims for damage
  • Cost you more money in the long run

So if you’re tempted to use that spare deep cycle battery you have lying around as a replacement for your car battery, it’s important you know the potential dangers and problems you will encounter from doing this.

If you would like some expert advice about the correct battery to use in your car, 4WD, ute, caravan, boat or motorbike, please feel free to talk with us and we would be more than happy to give you advice on the best battery solution for your vehicle.

We have the northside of Brisbane covered when it comes to your battery requirements so drop into one of our main stores at Brendale, Caboolture or North Lakes.


12 Garret Street
Brendale Qld 4500
Ph: 0413 692 236


6/106 Lear Jet Drive
Caboolture Qld 4510
Ph: (07) 5309 4905


12/88 Flinders Pde
North Lakes Qld 4509
Ph: (07) 3048 2293


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