Batteries that go in your van, to power all your electrical needs are called leisure batteries.
Don’t underestimate the importance of choosing the right campervan leisure battery, it’s the backbone of your electrical system and can make or break your off-grid adventures.
In this guide, we’ll lay out campervan batteries and explore everything from how they work to what features to look for when choosing one.
Considerations when choosing your battery
When choosing a campervan leisure battery, there are several key considerations to keep in mind:
Battery Type: Consider whether you want an AGM or lithium-ion battery, or other, based on your power needs and budget.
Capacity (Ah): The capacity of the battery is measured in Amp-hours (Ah) and determines how much energy it can hold at any given time. You will need to choose a capacity that meets your specific power requirements for appliances such as lights, fridge/freezer, charging devices like phones/laptops/cameras etc.
Lifetime/Cycle Life: This refers to the number of cycles before degradation occurs within the batteries. Lithium batteries have longer lifetimes than AGMs typically lasting 20-30 years compared with just 7 years. That’s a difference of 900 discharge/ charge cycles to 4500 cycles.
Depth Of Discharge: Depth of discharge (DOD) indicates what percentage range you should use between recharging & discharging the batteries; this varies by type but generally ranges around 50% for conventional deep-cycle batteries, while some high-end lithiums allow down to near zero levels without damaging them.
Weight And Dimensions: Make sure measurements fit inside available space where installed. Batteries are heavy.
Battery Management System(BMS): Some modern lithium ion-based models will come equipped with BMS’s, built-in monitoring modules, controlling load management/discharging rates rate limits and performance maximisation.
Charger Types And Charging Time Requirements: Double check charger compatibility specifications if you have something like solar or a split charge relay already purchased. Not all components play nicely together.
Operating Conditions: Make sure you choose a battery that can withstand the temperature range you are intending on driving through.
Cost-effectiveness: As always, how much do you want to spend? Batteries are expensive and some are more expensive than others. Lithium batteries are more expensive upfront than AGM’s but offer long-term cost savings due to their longer lifespan & higher capacity allowing for greater energy storage/usage across multiple cycles. Which is great, if you have £1,000 to spend upfront.
AGM vs Lithium
There are a few other types of batteries, Gel Batteries, Lead Acid batteries, and even start motor batteries (don’t use your starter motor), but the main two that people are using are either AGM or Lithium. Let’s look at their differences, there are pros and cons to each.
AGM (Absorbent Glass Mat) batteries:
Developed in the 1980s for military use, AGMs rose to glory for campervan owners due to their reliability. They are made up of glass fibres soaked with an electrolyte that is absorbed through capillaries, creating an even distribution of energy throughout the battery cells.
Pros of AGM batteries:
- Maintenance-free
- Last fairly long (around seven years)
- Resilient to vibrations making them perfect for off-road adventures
Cons of AGM batteries:
- Heavier and larger than their Lithium counterparts since they require more physical material inside each unit.
- You can only use 50% – as a maximum – of each charge before it must be charged again. If you dip below 50%, the next maximum charge amount is reduced, meaning you get less and less out of each full charge.
Lithium-Ion batteries
This latest technology is a fresh technology that offers superior performance over other options, by far, in longevity, cycle life capacity, improved charge, discharge rates and faster charging times. Kind of like a giant phone battery for your van.
Pros of lithium-ion batteries:
- Lighter total weight on a smaller footprint (30% less volume vs similar energy storage capacity)
- Higher Depth Of Discharge(DOD): You can discharge these cells down to nearly zero levels without damaging them unlike traditional deep cycle counterparts.
Cons of lithium-ion batteries:
- A Lot more expensive initial cost upfront if you go this route
- Lithium batteries have to be monitored more closely than AGMs as they cannot withstand extreme temperatures or weather conditions such as freezing temps which can damage cells beyond repair.
Battery monitoring
Keeping track of how much power remains in your camper van’s battery isn’t always easy without proper monitoring systems in place. For that, you will need a battery monitoring system.
The 12V Battery Monitoring system provides real-time information about your battery voltage levels (with simple LED voltmeters or sophisticated digital displays), which helps prevent running out of juice unexpectedly, or over-discharging.. something very important for AGM batteries.
In addition to preventing potential issues like being stuck powerless on some far-off mountain road, these systems help optimise energy usage too. If you have a solar panel setup this can help find the right balance between charging daily needs against available sunlight hours.
9 ways to maintain your battery
1. Regularly charge your battery: drive the vehicle for at least 1 hour once a week and hook up to mains electricity at least once a month.
2. Turn off everything when not in use: this includes lights, appliances, and especially the fridge as they can drain power even when not being used
3. Install a voltmeter to read and test your battery regularly to ensure it’s holding a charge. They are easy to add into a 12v installation.
4. Be mindful of how long your battery stays on mains power.
5. If you’re travelling in cold weather, keep your battery warm to prevent it from losing its charge. You can use a battery blanket or an insulation box to keep your battery warm.
6. Double check charger instructions for maintenance mode and safety precautions before leaving charger plugged-in whilst unattended for long periods.
7. Never let the AGM discharge as low as 50%. It will be irreparably damaged.
8. Use Solar. Solar panels are an ideal way to keep your campervan’s leisure batteries trickle charged.
9. Regularly check connections termination points ensure they’re clean/dry/adequately tightened against surrounding metal parts/vibrations/etc. If you notice any cracks or leaks, replace the battery immediately.
How to install a battery in your campervan
- Find the right place for your battery. This should be in your plan. Placement is key. Remember batteries are heavy, they will nearly always be on the floor or close to it, because of their weight. You shouldn’t need to get to your batteries all that often, but they should be accessible. They might need some ventilation, which means air around it. They should be completely secured so that they do not move around when the van is in motion.
- And you don’t want to place them near any water/ pipework etc. Secure them in, somehow. Whether that’s by screwing in a few bits of 2×1 or building some cabinetry around them.
- Protection. Wear goggles and long sleeves/ trousers when working with batteries. Weird, I know, but they have some dangerous stuff inside them that you don’t want on your skin or eyes. While you are at it, don’t smoke or do anything with a naked flame around batteries. A well ventilated space is recommended. If you do have any contact with battery liquids, seek medical attention quickly.
- Be careful when using metal tools around batteries. You don’t want to short circuit using your screwdriver or a wrench.
- Disconnect or otherwise isolate everything from the battery when working on it/ replacing it/ installing it. If you are disconnecting, always disconnect the negative terminal first (normally black in colour). Be careful of any live wires and what they could touch. DC shocks grab hold and don’t let go, and can be painful even at 12v’s. When you are connecting everything up, make sure it’s all tight and you’ve done a good job, following all manufacturers guidance.
- Label everything.
What we did
We inherited 2 x 110ah batteries with the van, squeezed together under the driver’s seat.
They both worked adequately enough, so we left them there.
We did need to re-do much of the 12v wiring though, so we bought some big fat cables that put the batteries into parallel.
2 big fat wires come out of the batteries. 1 goes to the rear 12v set up (straight into a fuse box) and the second goes to under our bench seat, where we have our front 12v set up (again, straight into the fuse box).
Also going into the batteries, we have the solar set up, and the split charge relay.
To be honest, even trying really hard for this not to be the case, the wires around the battery look a mess. It’s important to label things.
I would not recommend putting your batteries under the driver’s seat. In my van you need to take the whole seat off to get to them, which is a pain.
When it is time to replace the batteries, I will be installing a busbar to tidy everything up. They are inexpensive, easy to install and will make things much nicer. More on Busbars in the concepts and components guide.