Guide to leisure batteries for caravans and motorhomes

Owning your own caravan or motorhome means that you’ll need to become well-acquainted with the importance of leisure batteries.

So, whether you’re wondering how to charge a leisure battery on a caravan, exactly what one is, or what size battery you need for your caravan, we’ll run you through the basics and guide you through everything you need to know.  

What is a leisure battery?

A leisure battery will be essential to power the appliances and equipment in your caravan or motorhome, providing a power source for the 12V appliances. It will be required to provide a steady level of power over a prolonged period of time, to power the likes of:

  • The lights
  • Television
  • Kitchen appliances

The most common type of leisure batteries are lead-acid batteries in the following forms:

  • Standard starter batteries: Also called calcium or cranking batteries
  • Standard leisure batteries: Also called auxiliary or deep-cycling
  • Semi-traction and traction batteries: Also called deep-cycling batteries

There are alternative leisure batteries which include:

  • Gel batteries: Often used in vehicles like quad bikes or jet skis that have a higher chance of crashing as the gel removes the chance of corrosive acid leaking from the battery. Gel batteries are starting to be found in some imported caravans and motorhomes.
  • AGM batteries: Absorbent Glass Mat batteries have a longer lifespan than traditional lead-acid batteries although they are most expensive to produce.
  • Maintenance free batteries: These batteries have sealed units that can’t be topped up.

How do you charge the leisure battery in a caravan?

You should charge your caravan’s leisure battery from an external battery charger. Your caravan or motorhome will already be fitted with a charger, but this won’t be effective enough to charge your leisure battery and is just in place to keep the onboard equipment running.

How to choose the right leisure battery charger

A battery will need a charger with an output of at least 10% of the battery’s capacity. So, for example, a 90Ah battery will require a nine amp charger.

When to charge your leisure battery

Removing the leisure battery and charging it with a good charger will help it stay in good condition and working order. That means you need to know when to charge your caravan battery, how quickly, and how long for.

A good working guide is 50% of the maximum level of discharge before you recharge your battery, especially with lead-acid batteries.

Your Voltmeter reading will help you understand the approximate level of charge along the following lines:

  • 12.7V or over: 100%
  • 12.5V: 75%
  • 12.4V: 50%
  • 12.2V: 25%
  • 12V or under: Discharged

Is this the same in motorhomes?

Yes, it’s the same in motorhomes, as leisure batteries are used in both caravans and motorhomes. You should therefore follow the same guidelines when it comes to charging your leisure battery in your motorhome.

How long do you need to charge leisure batteries for?

Leisure batteries should be charged slowly as they are designed to provide low currency for long periods of time. It’s not advisable to give your leisure battery a short, fast charge.

How long you should charge a caravan battery will depend on its level of discharge and the type of battery. As a guide, it could easily take one or two days.

Maintaining your leisure battery

To keep your leisure battery working in top condition for as long as possible, do all that you can to look after it and perform essential ongoing maintenance.

How long do leisure batteries last?

The performance of leisure batteries decreases over time, meaning that they probably won’t last longer than five years. To give it the best chance of lasting for as long as possible, it’s important to:

  • Apply a thin layer of grease or Vaseline to the battery’s terminals.
  • Check regularly that the electrolyte level covers the lead plates on the battery. If it doesn’t, make sure you top it up with deionised water.
  • Use high quality clamps to keep it in place and ensure that any steel surfaces don’t rust.
  • Continually check that the gas relief tube is fitted correctly and securely.
  • Never allow the battery to completely run flat or leave it uncharged. Remember to stick to the ‘below 50%’ rule when it comes to recharging.

If you’re not using your caravan or motorhome, use a trickle charger to stop the leisure battery from completely losing charge when idle.

What size battery do I need for my caravan or motorhome?

Knowing what size of leisure battery you’ll need for your caravan or motorhome will depend on how you use it. Specifically, how often your trips take you to sites without electric hook-ups or how often you decide to be completely self-contained, coupled with the appliances and devices that you use.

The categories of leisure batteries are:

Category A: This is for higher storage capacity when you frequently use your caravan or motorhome away from electrical hook-ups.

Category B: If you often use sites with electrical hook-ups but need a greater battery capacity to operate devices that require a lot of power such as motor movers.

Category C: This lower capacity battery will cover basic operation of the main equipment and appliances on board your caravan or motorhome, for short periods away from an electrical hook-up.

Can a car battery be used in a caravan?

In theory you can use a car battery in a caravan, but it isn’t recommended. A car battery is designed to operate at close to 100% capacity, delivering power in short bursts. When using a car battery to power a caravan it will be discharged at a deeper level continuously, resulting in shorter battery life.

Remember, take your time to choose the right leisure battery to cater to your individual needs, and do all that you can to keep it maintained and in the best possible shape, so you can enjoy your caravan or motorhome to the full.