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A Complete Guide to Campervan Leisure Batteries (2024)

In this article, we are going deep on the campervan leisure battery. We will look at the different types of deep cycle leisure batteries (AGM, FLA, gel, and lithium ion leisure batteries), how to install leisure batteries in your van conversion, how to calculate the size of the battery, the best leisure batteries on the market, the lifespan you can expect from your batteries, how you can maximise that lifespan, and more. By the end, you will have a very thorough understanding campervan leisure batteries and be ready for your own electrical installation.


leisure batteries article intro image

 

Index


 

Shane, the founder of The Van Conversion, is a campervan professional dedicated to helping people transform ordinary vans into homes on wheels. He has authored Roaming Home, and teaches The Van Conversion Course, guiding many people through their van builds. Shane also writes The Van Conversion Newsletter, where he shares practical tips and insights. After completing two van builds and living on the road full-time since 2020, he is passionate about sharing his expertise with others.


This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc.) we will receive a commission fee. The price you pay remains the same, affiliate link or not. By using these links, you are helping me to continue writing free educational content! To understand our policies on content, affiliate commissions, and liability, please review our Terms of Use.


Note: Did you know you can get a free electrical wiring diagram by signing up for The Van Conversion Newsletter?


 

van conversion electrics guide

Supplies List

campervan renogy lithium leisure battery

Heavy duty bus bar

Busbars

Common connection point for positive and negative cables


Isolator switch

Isolator switch

Leisure battery kill switch

250a ANL fuse

Fuse holder with appropriate fuse

Protects the leisure battery in case of surge


Victron battery monitor

Battery monitor

For monitoring the levels/health of your leisure batteries


Leisure battery terminal connectors

​Leisure battery terminal connectors

For connecting cable to your leisure battery


What is a Leisure Battery?

A battery is a device that stores chemical energy and converts it to electricity on demand. In campervans, we store electricity in leisure batteries, which are designed specifically for the campervan use-case. This means that they're designed for comparatively deep discharging and many charging cycles reflecting years of use.


Best Leisure Battery for Campervans

The best leisure batteries for campervans are lithium-ion or LiFePO batteries. Whilst expensive, these batteries can be repeatedly discharged to 20% charge, giving you the most usable capacity of any battery type. Lithium batteries also outlast other battery types by a wide margin, meaning they're likely to last longer than your van itself before needing replacement. Both Renogy and Victron make high-quality lithium leisure batteries.


12V 200Ah Lithium Iron Phosphate Battery w/ Bluetooth

victron lithium leisure battery

If you're shopping in the US, LiTime are another notable manufacturer of lithium batteries. Their range include highly compact lithium leisure batteries, bluetooth-enabled smart batteries, and self-heating batteries for low temperatures. Use the code VAN6 at checkout to snag a 6% discount on all LiTime products.


Best compact RV battery

Starter Batteries vs. Deep Cycle Leisure Batteries

A starter or cranking battery is what kicks your van into action when you turn the ignition. Starter batteries are designed to provide a big burst of energy quickly and can use as much as 20% of their total capacity per ignition. Once the engine starts up, the alternator recharges the starter battery so it’s ready to go for the next time you start up.

Deep cycle leisure batteries, in contrast, release energy in a steady flow over a longer period. They are designed to withstand thousands of charging cycles.


Depth of Discharge and Battery Cycles

Leisure batteries can be safely discharged to a certain level, known as its depth of discharge (DoD). Discharging a leisure battery beyond its recommended DoD will drastically reduce its lifespan and may even damage it. A single discharge and subsequent recharge is known as a cycle. Lead-acid batteries can regularly be discharged to 50%, whereas lithium batteries can be discharged far more, to about 80%.

AGM vs. Gell cell batteries

This table shows the effect of depth of discharge on lifetime battery cycles for two types of lead-acid battery. We can clearly see the importance of caring for our batteries and not discharging them too deeply.


Sulfonation

We should be cautious never to completely drain our leisure batteries, and certainly should never leave a battery in a completely discharged state. If recharging is delayed, sulfonation occurs. During sulfonation, a white deposit forms on the battery’s plates.

Sometimes, sulfonation can cause the lead plates inside the batteries can fall over. When this happens, you will see that the battery voltage falls to weird levels like 8V or lower. This is not normal, and a deep cycle leisure battery should never fall below ~11V.

It is possible to bring a battery back from sulfonation by charging it up (typically with a very heavy charge initially). Some smart battery chargers can detect a sulfonated battery and revive it accordingly. However, the more you allow your batteries to fall flat, the worse sulfonation will get until the batteries are useless.


Leisure battery sulphination
Leisure battery sulphonation

For these reasons, we highly recommend that you install a battery monitor alongside your leisure battery. More on these later.


Regulatory Guidelines for Installing Leisure Batteries in Campervans (BS 7671 & NEC)

When installing leisure batteries in campervans, it's critical to follow established regulatory guidelines to ensure safety and compliance. These guidelines are outlined in BS 7671: IET Wiring Regulations (UK) and NEC: National Electrical Code (USA).


Below are key articles from each that apply directly to leisure battery installations in van conversions.


BS 7671 - UK Wiring Regulations

Article 721.521.1 – Flexible Wiring: Only flexible cables are permitted for DC wiring due to the movement and vibrations of vehicles. Solid core wiring (used in residential settings) is not allowed.


Article 721.55.1.1 – Isolation: An isolator switch must be installed between the leisure battery and connected loads to safely disconnect the system during maintenance or emergencies.


Article 721.411.3.1.1 – Earthing Requirements: Proper earthing is critical for DC systems in vehicles. The leisure battery’s negative terminal must be securely grounded to the vehicle chassis to prevent electrical faults.


Article 422.2.1 – Battery Ventilation: Flooded lead-acid (FLA) batteries require a ventilated enclosure to prevent the buildup of explosive gases like hydrogen. Ensure sufficient airflow with vents placed at both high and low points in the battery compartment.


Article 433.1.1 – Overcurrent Protection: Fuses or circuit breakers must be installed near the leisure battery’s terminals to protect the wiring in case of overload or short circuits.


Article 721.55.1.2 – Battery Leakage Protection: For FLA batteries, the battery compartment should be designed to prevent acid leakage from damaging other parts of the vehicle.


National Electrical Code (NEC) - United States

Article 551.30(A) – Low-Voltage DC Systems: All DC wiring must use appropriately rated cables for the current and include proper overcurrent protection. The maximum allowable DC voltage in these systems is 48V.


Article 551.20(A) – Ventilation of Battery Compartments: Flooded lead-acid batteries must be housed in ventilated compartments to avoid the accumulation of hydrogen gas, which can be explosive. Lithium batteries generally do not require ventilation.


Article 551.32(B) – Battery Interconnection: Properly sized cables must be used to interconnect multiple batteries, ensuring they can handle the combined load safely.


Article 551.40(A) – Battery Disconnect: A battery disconnect switch must be installed on the positive side of the battery circuit for safe disconnection during maintenance or emergencies.


Article 480.5 – Overcurrent Protection for Battery Circuits: Any conductor connected to the battery must have overcurrent protection (fuses or breakers) installed as close to the battery terminals as possible.


Article 110.26(D) – Terminal Protection: Battery terminals must be protected with insulating covers to prevent accidental contact, which could cause short circuits or electric shock.


General Guidelines for Leisure Battery Installations (Cross-regulation)

Battery Ventilation: Both BS 7671 and NEC require ventilation for FLA batteries to prevent the buildup of hazardous gases. Lithium batteries, which do not emit gases, typically do not require this level of ventilation.


Overcurrent Protection: Overcurrent protection (e.g., fuses or circuit breakers) must be placed as close to the battery terminals as possible in both BS 7671 (433.1.1) and NEC (480.5) to protect against electrical faults and short circuits.


Earthing: Proper earthing and bonding of the DC system is required in BS 7671 (721.411.3.1.1) and NEC (551.40). Grounding the leisure battery to the vehicle’s chassis helps prevent dangerous voltage differences during a fault.


Wiring Flexibility: Both codes emphasize the need for flexible cables (BS 7671 721.521.1, NEC 551.30(A)) in van conversions to handle the vehicle’s movement and vibrations, ensuring long-term reliability and safety.


By following these regulations, you'll ensure your campervan's leisure battery installation is safe, efficient, and compliant with industry standards, reducing risks and extending the system’s life.



Types of Campervan Leisure Batteries

At the highest level, there are two types of campervan leisure batteries:


  • Lead-acid batteries

  • Lithium (LiFePO4) batteries


Lead-Acid Batteries


Types of lead acid batteries

Lead-acid batteries are broken down into two subcategories:


  • Flooded (open/wet) lead-acid batteries

  • Sealed (VRLA) lead-acid batteries


In the Roaming Home 2023 study, we found that of those vans with either lithium or AGM batteries, 46% are now using lithium batteries. Compared to even five years ago this is a huge jump. The benefits of lithium batteries are substantial, even if they do come with a higher upfront cost.


Should I use lithium or AGM batteries

Flooded Lead-acid (FLA) Batteries

FLA batteries emit hydrogen gas and thus need to be adequately ventilated. Occasionally, they will need to be refilled with deionised water and must be kept securely upright. They are usually very cheap, but generally not recommended for van conversions due to the need for ventilation and maintenance. They have a lifespan of 4-8 years with regular maintenance.


Sealed Lead-acid (VRLA) Batteries

VRLA batteries are sealed and do not need any ventilation or topping up with deionised water. For these reasons, sealed lead-acid batteries are the best lead-acid batteries for van conversions.


If we dive just a little deeper into sealed lead-acid leisure batteries, we find that we have two types:


  • AGM batteries (Absorbed glass mat)

  • Gel cell batteries


AGM Batteries

AGM batteries are the cheapest type of sealed lead-acid battery. They are rugged and require no maintenance. They are the most popular type of battery for van conversions. They have a longer lifespan than flooded lead-acid batteries and work better in cold conditions. You can expect to get roughly 500 charge cycles (at 50% DoD) from a typical AGM leisure battery before it reaches 80% of its original capacity. In the US, Renogy are a popular manufacturer of AGM batteries.


Renogy 200Ah AGM Battery

Gel Batteries

Gel cell batteries have all the benefits of AGM leisure batteries but with a longer lifespan. You can expect to get roughly 1000 charge cycles (at 50% DOD) from a gel leisure battery.


AGM vs. Gell cell batteries

Gel leisure batteries also operate better in warmer and colder climates than AGM leisure batteries. Their only downside is that they're heavier and more expensive than AGM batteries.


Lithium-ion Leisure Batteries (LiFePO4)

There's a reason lithium, LiFePO, or LFP batteries are at the top of the campervan leisure battery pile. Lithium batteries provide as much energy as lead-acid batteries for a quarter the weight and a smaller size. They also have a significantly longer lifespan and can be discharged more deeply.


12v 200Ah Lithium Leisure Battery

victron lithium leisure battery

LiFePO4 batteries also are less prone to combustion than lead-acid, making them safer for campervan use. There is no liquid in a lithium battery, so they can even be mounted upside-down. They require no maintenance and charge much faster than lead-acid batteries.


When paired with a smart DC-DC or battery-to-battery charger, they charge up lightning quick when the engine is running. The importance of this fact cannot be understated. If you are staying stationary during winter (eg. doing a ski season in a van), and get little exposure to the sun, this is a lifesaver.


The catch is that lithium batteries are up to four times the price of a lead-acid battery, though prices are dropping as they get more popular. In this van converter's humble opinion, they are well worth the price.


It's worth mentioning that lithium batteries function worse in very cold temperatures in comparison to lead-acid. If you are using your van in cold locations, make sure you keep the van warm inside and don't mount your battery directly to your van's cold metal floor.


Categories of Campervan Leisure Battery

A campervan leisure battery is certified class A, B, or C by the National Caravan Council (NCC) in the UK. ‘A’ has the longest lifespan and is designed for frequent use, ‘C’ has the shortest lifespan and is designed for infrequent use or vans that are permanently hooked up.


  • Category A is for higher storage capacity for people who frequently use their campervans away from electrical hook-ups

  • Category B are aimed at those who frequently use sites with hook-up facilities, but require a greater battery capacity

  • Category C is for those who require a lower capacity battery, just to cover basic operation of their appliances for short periods away from a hook-up


It is worth pointing out that Category A batteries will be significantly heavier than their category C Counterpart. Weight is a good measure of quality with lead-acid batteries; the heavier, the better. I would suggest you grab yourself a nice, heavy category A leisure battery (or a Lithium battery).


How Long Does a Leisure Battery Last?

You can expect to get roughly 500 charge cycles (at 50% DOD) from a typical AGM leisure battery, and roughly 1000 charge cycles (at 50% DOD) from a gel leisure battery.

We can expect to get ~1150 charge cycles from a typical lithium ion leisure battery, though as the technology matures this number is rising to 2000 or 3000 cycles for some manufacturers.


When choosing a lead-acid leisure battery, it helps to understand a few key industry standards:


  1. 20-Hour Rate: This refers to the number of amps a battery can discharge over a 20-hour period at a constant rate, before the voltage drops below 1.75 volts per cell.

  2. Reserve Capacity: This is the number of minutes a battery can deliver a constant 25 amps before the voltage dips below 1.75 volts per cell at 26°C.

  3. Cold Cranking Amps (CCA): This measures how many amps a fully charged battery can maintain for 30 seconds at -18°C before voltage drops below 1.2V per cell. This is essential if you plan to use your van in cold climates​​.


Charging Profiles of Deep Cycle Leisure Batteries

Charging profiles of deep cycle leisure batteries normally follow three stages: bulk, absorption and float. The charging limits differ between the different battery types.


Charging Profile of Lead-acid Batteries

  • Bulk: a fast, constant current charge up to ~80% State of Charge (SoC)

  • Absorption: much slower, constant voltage charge to reach 100% SoC

  • Float: a constant voltage charge which maintains 100% SoC by counteracting self-discharge


Charging profiles of leisure batteries

Charging Profile of Lithium Batteries

The charging profile of lithium batteries differs from AGM, FLA, and gel. Lithium batteries go through two stages:


  • Constant current (roughly correlates with the bulk stage)

  • Constant voltage (roughly correlates with absorption stage)


Optimal charging profile of a lithium battery

In all leisure batteries, as the supply voltage increases, the current falls. The voltage and current move inversely.


Note how different batteries charge best at different voltages. Lead-acid batteries (AGM, Gel, FLA) in particular require large voltages in the bulk and absorption stages of the charge profile. Lithium leisure batteries are the inverse - they require less power initially and gradually ramp up.


These charging profiles are what make a good-quality solar charge controller or battery charger so important. These devices ensure that the voltage and amperage being supplied matches the current charge stage of the battery. It is paramount that they do their jobs correctly. For example, if we had four solar panels wired in series (74.4V) wired directly to our lead-acid leisure batteries, we would be in for a very, very dangerous time indeed. The sulphuric acid would begin to boil and the plastic casing would start to melt. Before long you would have no campervan left.


How to Maximise the Lifespan of your Campervan Leisure Batteries

  • Don't discharge your batteries too deeply, too often. A good rule of thumb is to not regularly discharge your batteries below 50%, whatever kind of battery you have

  • Never let your batteries remain less than 20% discharged or you risk sulfonation

  • Before mounting terminal clamps on the battery terminals, apply a thin layer of Vaseline to the battery’s terminals.

  • If you’re not using your campervan, make sure you use a trickle charger to battery at a healthy charge level

  • If you are using flooded lead-acid batteries, make sure you regularly check that the electrolyte level covers the lead plates on the battery, topping up with deionised water as necessary

  • Protect your battery from extreme temperatures


Factors Affecting the Performance of Leisure Batteries

Temperature

The colder the temperature, the poorer the performance of the battery. The Ah capacity stated on a battery is based on a temperature of 25°C, with each degree lower causing a 1% drop in performance. For example, an 110Ah battery operating in 15°C temperature will actually perform with a capacity of 100Ah. By contrast, battery lifespan reduceswith high temperatures. You're looking for the sweet middle ground at 25°C where neither capacity nor lifespan is affected.


Battery capacity vs battery life
Battery capacity vs battery life; Prostar, Temperature effects on battery capacity and service life, 2019, https://www.prostarsolar.net/article/temperature-effects-on-battery-capacity-and-service-life.html

Age

Leisure batteries experience a decrease in performance over time, similar to how your phone battery holds less charge as it gets older.


Power Consumption

If a large number of appliances are run from the leisure battery, it will discharge quicker and therefore need to be recharged more often. This frequent recharging will cause the battery to degrade sooner.


Specific Gravity

Specific gravity is a critical indicator of a lead-acid battery's state of charge. There is a direct correlation between specific gravity and the open circuit voltage of your battery. Over time, batteries naturally lose charge due to their environment. At average temperatures, a lead-acid battery loses about 0.001 specific gravity points per day, with discharge rates increasing on hot days. This means if you leave your van idle for several weeks, you might return to a sluggish battery due to this slow, natural discharge​.


Category

As mentioned before, Category B and C batteries will not last as long as Category A batteries due to there being less lead in the battery.


What Size Leisure Battery Do I Need?

Sizing a leisure battery requires you to calculate your electrical load and combine it with your battery's recommended depth of discharge and the number of days you want to spend off-grid.


Calculate Your Total Electrical Load

To calculate your battery size you will first need to fill out a load sheet.

Our load sizing calculator is a handy way of doing this.


load sizing calculator

Alternatively, download a load sheet spreadsheet at TheVanConversion.com/load-sheet.


van conversion appliance load watt hour spreadsheet

Number and quantity of appliances: In order to figure out the size of batteries required, we will first need to figure out all the appliances we want to have in our van. List these appliances and note the number of each.

Voltage: Note the voltage of the appliances. Most appliances will be 12V DC, though some will be 230V/110V AC.

Amps: Note the amps of each individual appliance (you can find this on the spec sheet for the appliance).

Total Amps: Total amps = quantity × amps.

Total Watts: Watts = total amps × voltage.

Hours of daily usage: Note the number of hours per day you estimate you will use the appliance.

Total Watt-hours: Total watt-hours = total watts × hours used.

Total load: adding together the total watt-hours of all our appliances, we arrive at the daily electricity usage, or load, of our system


campervan total watt hours

Convert Wh to Ah: We will quickly convert the Watt hours (Wh) to Amp hours (Ah) as Ah is more commonly used for sizing 12V leisure batteries.


Ah = Wh ÷ V

Ah = 1185Wh ÷ 12V = ~98Ah


In other words, we can expect to use 98Ah of battery power per day in our sample campervan.


Determine Your Required Battery Size

The calculations above showed us the total load of our devices. However, I want to be able to be off-grid for at least two days, allowing for the possibility that I'll go 2 days without charging my batteries. Therefore, I'm going to multiply the Ah by two to give me 196Ah.


One further caveat: remember we should only discharge batteries to 50%. We will actually need twice our calculated Ah.


2 × 196Ah = 392Ah


This gives us two full days off-grid, assuming no charging via solar or battery chargers during this time. Lithium batteries do not need to worry about this so much. Our handy battery sizing calculator will help you figure out exactly which battery is best for you based on your calculated usage.


battery sizing calculator

In the Roaming Home 2023 study, we found that most people install 100-200Ah batteries.

what size leisure battery should I buy?

How to Charge a Leisure Battery

There are three ways of charging leisure batteries in a campervan:



So, let's figure out how long it will take to recharge our leisure batteries with solar panels, a split charge relay, or shore power.


Battery Efficiency

Lithium batteries charge at nearly 100% efficiency, compared to the 85% efficiency of most lead-acid batteries. This is due to their charging profiles. The charging efficiency of lead-acid batteries gets particularly bad when they are discharged more than 50%.

Ambient temperature also has a big effect on the charging efficiency of batteries, with colder temperatures significantly lowering charging efficiency.


C-rating

A battery’s charge (and discharge) rate is determined by its C-rating. The C-rating of a leisure battery describes the rate at which one can charge or discharge said battery safely. The C-rating of a typical lead acid battery is 0.2C, whereas the C-rating of a lithium leisure battery is typically 0.5C. We won’t go into further detail on this, but in a nutshell: we are capped at how fast we can charge (or discharge) our batteries due to their C-rating.


How Long Does it Take to Charge Leisure Batteries?

We have built a battery charge time calculator which you may find helpful. It will tell you exactly how long in hours it will take for a full charge given your input parameters.


battery charge time calculator

How Long Does it Take to Charge Leisure Batteries from Solar Panels?

Let's say we have 4 × 100W solar panels, giving us a total of 400W. We know we have to fill up 392Ah or 2304Wh of battery using 400W of solar power:


2304Wh ÷ 400W = 5.8 hours


However, solar panels typically only output 70% of their rated wattage due to sun angle, heat, and other factors:


2304Wh ÷ (400W × 0.7) = 8.2 hours


If we are using lead- acid batteries we would add another hour or so to account for their 85% charge efficiency.


How Long Does it Take to Charge Leisure Batteries from a Split Charge Relay?

Let's look at both types of split charging: charging from a split charge relay or voltage sensitive relay and charging from a battery-to-battery or DC-DC charger.


Split Charge Relay/Voltage Sensitive Relay

As a rough average, a vehicle’s alternator typically delivers 1500W of electricity, though this can vary between 500W and 2500W depending on the make and age of the vehicle.

Using the same maths as before:


2304Wh ÷ 1500W = 1.5 hours


Hypothetically, it should only take 1.5 hours to charge the leisure battery from 50% capacity using a split charge relay (or VSR). However, besides being limited by our battery's C-rating, charge time will depend on the split charge relay's performance.

These relays don't deliver optimised voltage and current per the charging profile of the battery, resulting in a less efficient charge.


Battery-to-battery or DC-DC Charger

A battery-to-battery (B2B) charger will decrease the time it takes to charge a leisure battery by matching its voltage and current output with the battery's optimal charging profile.


The wattage that a battery charger delivers is directly related to the amp rating of the charger. B2B chargers are usually rated at 20, 40, or 60 amps. A 20A charger delivers 250W, a 60A charger delivers 750W. We can use this wattage to estimate the charge time of our batteries as we did above.


12V 60a DC-DC Battery Charger



Our smart charger calculator will help you choose the right size B2B charger for your system.


How Long to Charge a Leisure Battery from Mains?

Next, let's figure out how long it takes to charge a leisure battery from mains power. In order to charge our leisure batteries from mains power, we will need an AC to DC battery charger. The battery charger regulates the flow of electricity to the batteries and converts AC into DC.


For instance if we have a 30A battery charger, we can expect to fill our 196 Ah batteries in 196Ah ÷ 30A = 6.5 hours. We can add an extra hour or more to this if we are using a lead-acid battery.


Balanced vs. Unbalanced Charging

If you have multiple leisure batteries, they are typically wired in parallel. This keeps the voltage the same and increases the capacity. To wire leisure batteries in parallel, we simply connect all the positive terminals and all the negative terminals in a daisy chain arrangement. It's possible to wire leisure batteries in series, but this produces very different results. Read more about parallel and series wiring setups here.


With multiple batteries wired together, it's important to configure the battery bank so all batteries are charged and discharged as equally as possible. This prevents one battery from working harder than another. This is known as balanced charging.


Unbalanced battery charging

Above is an example of a battery bank wired incorrectly, resulting in unbalanced charging. In this configuration, the battery on the right is doing the most work. Notice how both the positive and negative feeds from the battery charger go to the same battery.


Instead, we should have the positive and negative feeds from the battery charger going to batteries on either side of the bank.


balanced battery charging

This effectively balances out the charge that the batteries receive.


How to Use a Leisure Battery When Camping

Normally, campervan leisure batteries stay inside the vehicle, in a permanent, fixed position. They're not indended to be moved outside of the van whilst camping. This is where portable power stations come in. These devices have become exceedingly popular in recent years and are improving constantly. Portable power stations are lithium leisure batteries designed for portability and outdoor use.


We have written an extensive guide to portable power stations which discusses them in depth. There are a few very popular manufacturers, including EcoFlow, Jackery, and Bluetti. Our top picks are Bluetti and EcoFlow, which combine high-quality lithium batteries and full feature sets with reasonable prices.


campervan leisure battery bluetti

campervan leisure battery ecoflow

How to Install Leisure Batteries in a Van Conversion

Step 1: Install battery terminal clamps

First install clamps on the terminals of your leisure batteries. Apply a thin layer of Vaseline to the battery’s terminals before mounting the terminal clamps on the battery terminals.

leisure battery connector

Step 2: Connect the leisure batteries to positive and negative bus bars

Run a thick positive and negative cable from each bus bar to the leisure battery. The cable is connected to the bus bars and battery terminals using heavy duty lugs.

Wiring up leisure batteries

heavy duty bus bars for campervan leisure batteries

Step 3: Wire an isolator switch and terminal fuse

On the positive cable, add an isolator switch and terminal fuse.

250a inline ANL fuse for campervan leisure battery
250A inline ANL fuse

Don’t forget to ground your negative bus bar (or leisure battery). This is a very important safety requirement.


isolator switch
Isolator switch

How to Test a Leisure Battery

There are three ways of checking the charge level of your leisure batteries:



To determine how full a leisure battery is, we look at the voltage of the battery.


What should a 12 volt leisure battery read when fully charged?

Voltmeter

To see the charge of your batteries with a voltmeter, simply touch the positive node of the voltmeter to the positive terminal of the battery, and the negative to the negative.


voltmeter for leisure batteries

Battery Monitor

A more permanent way of checking the levels of our batteries is to hook up a battery monitor. A battery monitor gives insights into the health and usage of your leisure batteries. It'll tell you your battery's current charge status and how quickly it's charging.


A battery monitor with a physical display is very useful, as is one with Bluetooth connectivity. Such 'smart' monitors, like the Victron SmartShunt, allow you to monitor your batteries from your phone.


Battery monitor wiring

To install one of these, you will need to install a 'shunt' on the negative line leading from the bus bar to the batteries. We also wire the shunt directly to the positive terminal of the leisure battery. Finally, we can connect a battery monitor to the shunt.


Victron Smartshunt for campervan leisure batteries

Solar Charge Controller Monitor

A charge controller monitor is a device that plugs into your solar charge controller. Like a battery monitor, it gives you data on the status of your batteries whilst being much easier to install. If you have a Renogy solar charge controller, you can use their Bluetooth battery monitors which simply plug into a dedicated socket on the charge controller.


 bluetooth monitor for campervan leisure batteries

If you're using a Victron solar charge controller, you'll need to use their smart dongle instead.


victron smart dongle for campervan leisure batteries

Conclusion

We covered a lot of ground, but you should now feel equipped to size, choose, install, and look after a campervan leisure battery. Make sure you check out our longform articles on specific electrical components, including solar systems, inverters, and shore power to get a complete picture those components as well. When it's time to buy your batteries, consider Victron and Renogy's leisure batteries, which will serve you for many years.


 


campervan electrics guide

Don't forget to subscribe to The Van Conversion Newsletter for everything you need to get started with your own van conversion (we'll send you a free wiring diagram when you join).


If you're looking for some guidance with your van conversion, you might be interested in our book Roaming Home, or in our online course The Van Conversion Mastery Course. You'll learn directly from our founder Shane how to convert a van into your dream home - no prior experience needed.


 

Until next time.

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