How to test a leisure battery on a motorhome or campervan

If you’ve ever woken up on a frosty morning in your campervan only to discover your lights don’t work or your heater won’t switch on, then you already know the value of a good leisure battery. But how do you know when it’s time to replace it? Or if something’s draining it behind your back?

In this guide, we’ll look at how to test a leisure battery on a motorhome or campervan in a safe, sensible way. We’ll cover the basics, including what a leisure battery actually does, common signs it’s on the way out, and how you can get it tested properly by a professional.

 

 

What is a leisure battery?

First, it's important to understand what a leisure battery is and how it's different from your standard car battery.

A leisure battery is a rechargeable battery that provides low, steady power over a long period of time. It's what keeps your campervan or motorhome electrics running when you're parked up – from your lights and water pump to your fridge, heater, or TV.

 

What does a leisure battery power?

Here’s a quick list of things your leisure battery might be powering when your engine’s off:

• LED interior lights
• USB sockets and phone chargers
• Water pump (for taps and shower)
• Electric step
• TV/DVD player
• Heating controls and fans
• 12V fridge
• Alarm or tracker systems

Basically, all the creature comforts that make your campervan or motorhome more homely.

 

How to test a leisure battery (the safe way)

While it might be tempting to grab a multimeter and give it a go, working with electricity can be extremely dangerous. The best option is to get it tested at a garage, motorhome specialist, or battery centre.

However, it's still useful to understand what's being tested and what to look out for. That way, you can clearly explain the problem and know when something's not right.

Signs your leisure battery might need testing:

• Your 12V lights are dim or flickering
• Your fridge, heater, or water pump won't power on
• USB chargers cut in and out
• The battery shows a warning light or display error
• The battery doesn't hold charge even after driving or hooking up to EHU (Electric Hook-Up)
• It's more than 4-5 years old

 

 

What does a proper battery test involve?

When you take your leisure battery to be tested, here’s what the professionals usually do:

1. Visual inspection

They’ll check for corrosion on the terminals, swelling or leaks in the casing, and any signs of damage. Even dust or loose connections can cause power issues.

2. Voltage test

Experts use a multimeter to see the resting voltage of your battery (this is usually done when the battery is not powering anything).

Battery charge level = voltage reading (12V battery):

• 100% Charged = 12.7 – 12.9V
• 75% Charged = ~12.5V
• 50% Charged = ~12.2V
• 25% Charged = ~12.0V
• Flat/Dead Below = 11.8V

Don’t confuse this with charging voltage! When plugged into mains or solar, the battery voltage will read much higher (13.6–14.4V). That’s why resting voltage is the best way to check charge.

3. Load testing

A load test checks how your battery performs under strain, for example, simulating running your fridge or lights for a period of time. If the voltage drops too quickly under load, it's a sign the battery is on its way out.

4. Capacity test (Amp-Hour Test)

More advanced garages might perform a discharge test to see how many amp-hours the battery can still hold. Over time, batteries lose capacity, so even if it says "100Ah" on the sticker, it might only be delivering 40Ah after a few years.

 

Do I need a special battery tester?

If you're curious, there are basic multimeters or battery testers you can buy online (some under £20). These plug into a 12V socket and show you the voltage level.

Just keep in mind that they:

• Won't give a full picture of battery health
• Don't test under load or check capacity
• Can't diagnose wiring or charging system issues

So, while these can be handy, they don't give a full check-up.

 

Is it safe to test my battery myself?

It is not a good idea to test the battery yourself.

Here’s why:

• Incorrect testing can cause electric shocks or damage the battery
• Using the wrong tester or testing the wrong terminal could short the battery
• Older or damaged batteries can leak dangerous acid

If you're not confident or trained in 12V electrics, the best thing you can do is book into a trusted garage or motorhome workshop and let them do the testing. It’s quick, not too costly, and much safer.

 

 

How long does a leisure battery last?

Most decent leisure batteries will last four to six years. This depends on:

• How often you use them
• Whether they’ve been kept charged (especially over winter)
• If your charging system is working properly

Tip: Never let your battery fully discharge. That’s the fastest way to shorten its life.

 

Top tips to keep your leisure battery in the best shape

Want to keep your battery in good condition? Here are some tips:

1. Charge it regularly, especially in winter (use a smart charger or solar trickle charger)
2. Don’t fully discharge (run flat) — try to stay above 50% charge
3. Keep terminals clean and check for corrosion
4. Store indoors if removing over winter (cold kills batteries faster)
5. Avoid overloading - know what your battery can realistically power

 

Choosing the right replacement

If your leisure battery is tested and turns out to be on its last legs, it might be time for a new one. But there’s a bit more to it than just buying the cheapest one online.

Here are the main types of leisure batteries:

Flooded Lead-Acid

• Pros: Cheapest, widely available
• Cons: Needs ventilation, can spill

AGM 

• Pros: Low maintenance, more durable
• Cons: More expensive than flooded

Gel

• Pros: Good when fully discharged
• Cons: Can be damaged by fast charging

Lithium (LiFePO4)

• Pros: Lightweight, lasts 10+ years
• Cons: High purchase cost

Check your campervan's manual, or speak to an expert to ensure you choose a battery that suits your charging system, appliances, and budget.

 

When to visit a garage or specialist

You should definitely get your leisure battery tested or replaced by a professional if:

• Your electrics are acting up or inconsistent
• Your battery is older than four years
• You’re not sure if it’s charging properly
• You’ve just bought a second-hand van and don’t know the battery’s history
• You’re heading off on a long trip and want peace of mind

Most motorhome service centres can test your battery for you, and it usually only takes 10–20 minutes.

 

How to test a leisure battery the smart way

Testing a leisure battery is about keeping your campervan life running smoothly. Whether you're heading to the Lake District for a weekend or going on a big adventure around Europe, a reliable leisure battery makes all the difference.

Just remember:

• Don’t risk it with DIY electrics unless you’re confident
• Look out for signs your battery might be struggling
• Pop to a garage or specialist to test your leisure battery safely
• Treat your battery well

 

Specialist motorhome insurance through Ripe

When your leisure battery is charged up and ready to go, it's time for your next adventure. Before you head out on the road, you may want to consider getting specialist motorhome insurance.

Through Ripe, you can protect your motorhome from theft, accidental damage, fire, flood, and more. You can also get cover for your motorhome equipment and accessories, giving you complete peace of mind on the road.

Find out more about specialist motorhome insurance through Ripe or get a quote online today.