Camper van batteries are essential to providing power to all the electrical devices in your van. If you plan on having a fan, fridge, lights, or outlets for charging, you will need batteries to power them.
Theoretically, you could connect all of your devices to your vehicle starter battery. However, we do not recommend you do this. Starter batteries are not made to supply continuous power over long periods of time. If you were to connect your electrical devices to the starter battery, it would quickly drain and it’s lifespan would shorten drastically.
That is why most camper vans have a secondary battery in the back that is dedicated to providing power to your living space. These are often called “leisure” or “auxiliary” batteries.
This post will guide you through the battery selection process so that you will choose the right battery that fits your van life requirements. At the end of this post, we show you how you can install this battery in your van.
Table of Contents
- What to Consider Before Buying a Battery
- AGM Vs. Lithium Batteries
- Best Batteries for Van Life
- How to Calculate Your Battery Size
- How to Charge a Leisure Battery
- Maximize Battery Lifespan
- Determine Battery Charge Percentage
- How to Install a Battery
What to Consider Before Buying a Battery
There are a number of questions you need to answer when beginning the search for a secondary battery. Below we list three of the most important considerations to think about before finalizing your battery solution.
Like everything in this world, batteries come in a wide range of price points. Older technology batteries, like lead-acid and AGM, are cheaper than the newer lithium batteries that you can buy online today. Knowing how much your budget allows for battery purchases can help guide your decision to which battery is best for you.
Length of Travel
Batteries have varying lifespans. The less you might spend on a battery, the shorter the life span. A cheaper battery might work for you if you plan to use your van for weekend getaways. But if you are intending to live and travel full time, it may be worth it to upgrade to a battery with a longer lifespan.
The amount of battery that you need depends on the kind of electrical devices you want to power. Someone who wants to operate a water heater, hair dryer, and toaster oven, will need considerably more battery power than someone who intends to only power a few lights, and charge a smartphone. Jump here to learn how to calculate your ideal battery size.
AGM Vs. Lithium Batteries (Pros & Cons)
There are a number of different battery chemistries to choose from, such as lead acid, gel, and lithium. We have found that the two types of batteries that are most condusive to van life are AGM (which is a type of lead acid) and lithium batteries. In this section we compare these two battery technologies and give our recommendation as to which we prefer.
AGM - The Budget Battery Solution
Compared to lithium batteries, AGMs are considerably cheaper, often half the price. However, the downsides are that they have a considerably shorter life span (~600 charge cycles), and weigh twice as much.
AGM batteries are good for camper vans if budget is a concern and you only plan to travel part time with your van. Generally, under constant ‘deep-cycle’ use (50% DoD), AGM batteries have a useable life span between 1-2 years. So, if your travels will be less than this time frame, AGM batteries can be a good financial choice.
Lithium - The Modern Day Work Horse
Lithium batteries – more formally known as lithium iron phosphate batteries (LiFePO4) – have a higher up front cost compared to AGMs. Lithium batteries sell for anywhere between $300-$900 USD for a standard 12V 100Ah battery. However, lithium batteries have a considerably longer life span (~3000 charge cycles), can be safely discharged to lower levels, and are half the weight.
Lithium batteries are a great choice for camper vans that demand lots of power and plan to travel for longer than two years, which is when a well-maintained AGM would need to be replaced. At that point, most lithium batteries surpass AGMs as the cheaper option when factoring in cost per charge cycle.
Head to Head Comparison
We reviewed 10 AGM and lithium batteries and took the averages of all the information to present side by side for easier comparison.
Average Charge Cycles
Depth of Discharge
From the information in the table above, you can see that on average, that the cost to own an AGM ($204) is significantly lower than a lithium battery ($470). However, when factoring lifespan, lithium batteries become the cheaper option on a ‘cost per charge cycle’ evaluation ($0.13 vs. $0.34 per cycle).
Our Battery Type Recommendation
Due to their low cost over the long run, we recommend going with lithium batteries. We believe that the AGM’s lower rated charge cycles combined with their sensitivities to deeper discharges are unsuitable to long-term camper van living and travel.
We have been using lithium batteries in our van for over 4 years of continuous travel and have had zero problems with their ability to keep up with our power demands.
Additional Lithium Benefit
Unlike AGMs, lithium batteries have substantial resale value due to their longer lifespans. Though you pay more for lithium batteries upfront, you can recoup much of that money if/when you decide to sell your camper.
Best Batteries for Van Life (3 Recommendations)
In this chapter we recommend three lithium batteries that we think are well suited for van life. Two of these batteries are budget lithiums that we reviewed and are sold at a great price point. The third battery is a premium lithium battery we have used for over 4 years on our travels.
Li Time "TM" Battery
If given the chance to build another camper van, we would use Li Time’s TM lithium battery. The battery comes with a robust battery management system (BMS) that protects the battery from over discharging, over heating, and stops the charge process when temperatures are below freezing.
This is Li Time’s Trolling Motor branded battery, this means that this particular battery has superior shock resistance and better withstands the impact of continuous motion and vibration.
Our top lithium battery recommendation! The Li Time "TM" packs a serious punch in a compact enclosure. Wide-ranging BMS with low-temperature protection. And superior shock resistance.
Redodo "Mini" Battery
The Redodo mini is one of the most affordable and light weight lithium batteries on the market today. It also has a capable BMS that protects the lithium cells during charging and discharging. However, the Mini does not have the low-temperature protection that the Li Time TM battery has, which may or may not be important depending on your travel plans.
We recommend the Redodo Mini for those that can afford to upgrade to a lithium battery, but are still on a tight van conversion budget.
Lithium batteries outperform standard AGM batteries in virtually every category. The 12V Redodo battery is a great option (at a fantastic price) to 'go lithium' without breaking the bank.
Battle Born Battery
We have used these batteries in our van for over 4 years, and love the Battle Born brand. They are considered premium lithium batteries and come at a premium price, which is roughly 3 times the price of the batteries that we recommended above. If you are a believer of the phrase “you get what you pay for”, then Battle Born batteries are for you.
If you want our opinion, however, we would recommend the Li Time battery above. It’s almost 1/3 the price of a Battle Born and comes with similar features, like the low-temperature cutoff protection. Even if a Li Time battery were to last half the time of a Battle Born, you’d still come out ahead in terms of value.
We've used these Battle Born batteries for 4+ years in our camper and have kept up with our power needs the entire time. This is a premium battery that comes at a premium price, however.
How To Calculate Your Battery Size
After choosing the battery (type and brand) for your van, you will next want to calculate how much battery you will need. Most individual leisure batteries are specifically rated for 12.8V and 100Ah. That is 1280 Watt-hours (Wh) of power. The three batteries we recommended above are all rated for 1280Wh.
Just because a single battery is rated for 1280Ah, however, does not mean this is the size your camper van requires. In many cases, camper vans will require MORE than 1280Wh of power to run all the many different electronic devices in the van. In fact, based on our calculations, we opted for three batteries for a total of 3840Wh of total power.
Prevent Dead Batteries: Batteries die prematurely when they are overused and overdischarged, which happens often when a van has too small a battery bank. With properly sized batteries, you will extend the lifespan of your batteries and maximize their value.
We provide two options to help you determine what size battery bank you will need for your camper van:
- Simple table: Easy & quick to use and accurate
- DIY spreadsheet: For those who enjoy getting a more nuanced answer
1. Simple Table
From our experience, most camper vans can be lumped into three categories; light, moderate, and heavy electrical demands. The table below draws distinctions between these three categories. Identify the electrical devices you intend to use in your camper van to determine what size battery you need.
Note: The battery size recommendation in below table is for lithium (LiFePO4) batteries operating at 12V. If using AGM, double the table’s recommended battery size. If installing 24V lithium batteries, divide the table’s recommendation in half.
Only plan to use:
2. DIY Spreadsheet
To get a more accurate battery size recommendation, download our battery calculator spreadsheet. It is a Google Spreadsheet document and is free to use.
To use the calculator effectively, you will need to know:
- All the electrical devices you plan to have
- How many units of each device there will be (i.e. one laptop or six LED lights)
- How many Watts each device will require to operate
And that’s it. Our battery calculator will then recommend you how much battery power your camper van will require, whether you choose AGM or lithium, to adequately power all your devices on a daily basis. If you would like more detailed, step-by-step instruction, check out our battery calculator post.
How To Charge Camper Van Batteries
There are four common ways to charge the leisure batteries and you are not required to choose only one method. Many camper vans often select two, or even three, battery charging solutions. The four charging methods are:
- Solar panels
- DC-DC charger (from vehicle alternator)
- Shore power
- Generator (gas/propane)
Below, we briefly talk about each charging method, review their pros and cons, and give product recommendations. For more in-depth information, check out our battery charging solutions post.
Charging Leisure Batteries With Solar Power
Solar panels are one of the most popular ways to charge leisure batteries in a camper van and is one of the only environmentally sustainable ways to generate power. It is also a passive charging process, meaning as long as the solar panels are receiving sunlight, your batteries will be receiving a charge. There is no other work on your end that you are required to do.
We've spoken with BougeRV reps and came away impressed with their customer service. They also make great quality, highly efficient '9BB' solar panels. Consider installing a larger 200W panel instead of multiple smaller panels. But use our solar calculator first!
There are two downsides to using solar panels. The first one is that solar panels are not particularly efficient at converting sunlight into power. Because of this, charging via solar panels is one of the slowest ways to put power back into your batteries. The second downside is that the solar panels require clear and direct sunlight. Extended periods of cloudy and rainy days, or parking in the shade, means you won’t be able to rely on solar panels to adequately recharge the batteries each day. But! This exactly why we mentioned earlier that you don’t have to only pick one way of recharging your batteries.
How Much Solar Do You Need?
The more solar watts you have, the faster the leisure batteries will recharge. How much solar your camper van needs depends entirely on your situation. Refer to our solar size calculator to help you determine your solar needs.(Note: This solar calculator is intended to be used in conjunction with our battery calculator and won’t be accurate just by itself).
Charging Leisure Batteries From A DC-DC Charger
By connecting the leisure batteries to a DC-DC charger, you can charge the batteries while driving your van. This is possible because the DC-DC charger will also be wired to your vehicle’s starter battery, which will be receiving a charge from the alternator while the engine is running.
It can get a bit technical, but just know that as long as your engine is running, your leisure batteries will be receiving a charge.
Charge your leisure batteries quickly with Victron's 30A DC-DC charger (up to 360W). Works great for both lithium and AGM batteries. But the highlight is the charger's Bluetooth connectivity, which pairs with Victron's UI-friendly smartphone app.
The upsides of having a DC-DC charger is that you aren’t constrained by weather and sunlight, unlike solar panels. As long as you have gas in the tank and a functioning engine, you will be able to charge your leisure batteries.
The downside is that DC-DC chargers only realistically work when driving long distances (i.e over an hour). Short 5-minutes drives to the nearby grocery store won’t be enough to charge the batteries if this is your only charging solution.
Our take? We highly recommend pairing a DC-DC charger with solar panels to provide a comprehensive battery charging solution. When solar panels become unreliable, due to weather or shade, DC chargers can pick up the battery charging slack. And vice versa.
Charging Leisure Batteries From Shore Power
You can also charge leisure batteries by connecting them to shore power. Shore power is any standard public electrical socket. These sockets can be located at campsites, truck stops, or even in the garage at home. You will need either a dedicated battery charger or an inverter/charger combo unit to take advantage of shore power charging.
Simple dedicated battery charger to recharge batteries from shore power.
Powerful 2000W inverter/charger combo unit. Converters 12V DC power to 110V AC and vise versa. We use this unit in our camper van.
The pros of shore power charging is that, when plugged in, you have access to limitless power to recharge your leisure batteries. You are not dependent on sunlight or driving to provide power to the batteries. It is the most convenient charging method.
The con of shore power is that if you are unwilling to pay for a pricey campsite, it can be difficult to locate a shore power socket. And since we often choose to free camp to save money, shore power charging is our least popular charging method.
Charging Leisure Batteries From A Generator
The last, and least popular charging method, is to connect the batteries to a generator. Essentially with a generator, you are creating your own shore power socket. As a result, you will still need a battery charger unit, like the two we recommended in the section above, to charge the leisure batteries from the generator.
The upside of carrying a generator is that you have access to dedicated power, even when boondocking far out in nature. As long as you have gas or propane in the tank, you will have power.
In our opinion, however, the downsides are substantial. Not only are generators bulky and heavy, but they also require fuel and are loud when in operation. We wouldn’t feel comfortable using a generator in a public setting with other campers around us.
How To Maximize The Lifespan Of A Leisure Battery
Leisure battery lifespan is expressed in terms of “charge cycles”, which is the number of complete charges and discharges a battery can undergo before it is deemed unusable. (Source)
However, relying on a battery’s rated number of charge cycles is tricky. A battery may be rated for 600 charge cycles, but this does not guarantee that the battery will provide 600 cycles of power in real life scenarios. If a battery is poorly treated, it’s lifespan may only be half of what it’s rated charge cycle is. Conversely, if you treat your battery well, you can extend it’s life beyond the rated charge cycle.
So, what can you do to maximize a batteries lifespan (i.e. charge cycles)?
Generally speaking, the greater a battery is discharged the shorter it’s lifespan. But a more in-depth answer depends on whether you are using AGM or lithium batteries.
Maximizing Lifespan Of Lithium Batteries
Below is a useful chart indicating the relationship between how a lithium battery is charged/discharged and it’s age (capacity to hold a charge). Each of the colors below represents a lithium battery that is charged and discharged to different levels.
The key takeaways from this study are:
- Do not charge (and keep) a lithium battery at 100% charge. Doing so significantly shortens the battery’s lifespan.
- Keeping a maximum charge of 75% is ideal
- Try to discharge the battery as little as possible below 75%. Down to only 65% is ideal. (But keeping it to above 45% charge is likely more realistic.)
Our Lithium Experience: In order to maximize the lifespan of our lithium batteries, we are constantly monitoring their state-of-charge. We also continually turn on and off our solar charge controller and DC-DC charger in order to keep our batteries within the 45%-75% charge range.
Maximizing The Lifespan Of AGM Batteries
Unlike lithium batteries, AGMs like to be charged to (and kept at) 100%. But the deeper AGMs are discharged past 100%, the shorter their lifespans are. In the below chart, you can see how a greater depth-of-discharge (DoD) of an AGM battery reduces it’s rated number of charge cycles.
The key takeaway of this chart is:
- Try to discharge an AGM battery as shallow as possible.
- If only discharging down to 50% each time, expect an AGM battery to provide ~650 charge cycles.
How To Determine A Battery's State of Charge (SoC)?
Unlike a cellphone or laptop that shows you exactly what percentage charged the battery is at, leisure batteries don’t display this information. Then how are you supposed to know what percent charged the battery is? There are two methods to determine a leisure battery’s state of charge (SoC).
- Multimeter (the budget way)
- Battery monitor (our pick)
We describe both these methods in more detail below and their pros and cons.
1. Multimeter (The Budget Way)
A digital multimeter is a multipurpose tool used to diagnose electrical issues. One of the many features of the multimeter is to measure a battery’s voltage. Simply switch the dial to the appropriate readout location and then connect the red and black test leads onto the appropriate battery terminals. The multimeter should then display the battery’s voltage.
As a battery is discharged, it’s voltage decreases. So by evaluating the battery’s instantaneous voltage, you can determine its percentage charge. Refer to the chart below to see the relationship between a battery’s voltage and it’s state-of-charge.
We color coded the cells to represent the following information:
- Green Cells: Maintain battery voltage in this zone
- Yellow Cells: Try not to enter these zones too frequently
- Red Cells: Avoid these zones as much as ppossible
The benefit of using a multimeter to measure the battery’s charge percentage is that these tools are cheap to buy and easy to use. The downside, however, is that using this tool is labor intensive. You constantly have to take the tool out, unpack it, and touch the leads to the battery terminals.
2. Battery Monitor (Our Pick)
Battery monitors are our preferred method to determining a battery’s state of charge. These monitors typically come with two components; a shunt that is connected in-line to the battery and a display unit. Below we recommend a budget and higher-end monitor. The latter has Bluetooth capability and can pair with a smartphone to display a plethora of battery information directly on your phone.
The benefit of using a battery monitor is that, by using the display, checking the battery’s state of charge becomes a quick and easy endeavor. Most battery monitors also display other useful information, such as instantaneous current flows into and out of the battery.
The drawbacks of using a battery monitor is that they will require some installation and are more costly than a simple multimeter.
How To Install A Leisure Battery In A Camper Van
This last chapter will discuss how to install a leisure battery in a camper van. We separate this into three sections:
- Tying down the batteries
- Wiring multiple batteries together
- Connecting batteries to the bus bars
1. Tying Down The Batteries
When installing batteries in a camper van, you need to ensure that the batteries are sufficiently tied down so that they won’t vibrate and move while your van is in motion. This can be challenging especially when considering just how heavy leisure batteries are (~25-60lbs each).
Some camper vans use ratchet straps to tie down their batteries. This can be difficult, however, if you don’t have sufficient anchor points. You may also need to use multiple ratchet straps to prevent horizontal and vertical battery movement.
Our solution was to attach our three batteries to small plywood boards via heavy duty 3M VHB double-sided tape. Once completed, we fixed the plywood boards to our sub-floor with large wood screws. In this way, we are able to limit movement of our batteries. Refer to the below image to see how we did this.
2. Wiring Multiple Batteries Together
If you have multiple batteries, you will need to decide whether to wire the batteries together in “parallel” or in “series”. Below are two diagrams that illustrate the physical differences between parallel and series battery wiring.
If you are building a 12V system (which you most likely SHOULD be doing) and are using 12V batteries, your only choice is to wire your batteries together in parallel. Not in series.
Life Pro Tip: To make things easier, you can skip this step entirely by buying single 200Ah and 300Ah batteries. This way you do not have to wire together two or three 100Ah batteries. This is what we would do instead, if we were to build another camper van.
Read our 12V vs. 24V battery post if you want to know more about the pros and cons of each wiring type.
3. Connecting Leisure Batteries To The Bus Bars
Connecting the leisure batteries to the bus bars is the most basic and foundational step of any camper van electrical system. Once completed, you can wire all future downstream devices (i.e. 12V panel, inverter, solar charge controller, & DC-DC charger) to these bus bars and they will automatically be connected to the batteries.
Follow the diagram below to learn how – and what materials you will need – to complete this wiring process.
List Of Materials
Below is a comprehensive list of materials you’ll need to complete this section.
And lastly…Our electrical diagrams PDF is a fantastic resource if you are looking to build an electric system with the least amount of effort and in the quickest amount of time. For comprehensive wiring information, including solar and inverter, download our electrical wiring eBook
There are over 35 pages of detailed content and this PDF is completely free to download and use.
Download our FREE PDF to help build your van's electrical system; from batteries, to solar, to inverter, and more. 38+ pages of detailed diagrams, product recommendations, and links to additional resources.
There is a tremendous amount of information regarding the topic of camper van batteries, and it can often feel like a deep rabbit hole once you start the research process. We hope this post provides only the information that is necessary to know so that you can build the best battery setup for your camper van conversion.
When you are ready, we encourage you to visit our complete electrical installation guide for camper vans, which provides step-by-step installation guidance with tips and recommended material lists.
If you have any additional questions or uncertainties, please feel free to comment below or send us an email.