Fitting My Van with a Removable Auxiliary Battery
Objective: Understand the different battery technologies available and choose the one that best suits van life. We will also consider installation, safety, performance, and of course, cost.
Lithium-ion, GEL, AGM, Nickel, LCO, Lead... There are many terms to describe a battery, which can lead to confusion. In this article, we will clarify the existing technologies and their main applications to select the best compromise for our use case.
Table of Contents
The Product We Are Looking For
As a reminder, the basic principle of Combeing is to transform your utility van into a camper van on a budget in just a few minutes (assembly, disassembly). To achieve this, we have developed a modular system that can be customized according to your preferences, allowing you to hit the road on a whim.
To accompany this setup, we were looking for a battery that would match our values of simplicity and flexibility. Therefore, we selected important criteria for use that align with the habits of our community. Here are the criteria we chose:
- A long lifespan (for us, the product is a long-term investment)
- A good capacity in Wh (directly related to energy density)
- A high thermal stability (minimizing the risk of fire/explosion)
- A low self-discharge rate (our users store the battery between uses)
- A fast charging time
- A sufficient voltage for standard van accessories (the power of a battery)
- A strategic operating temperature
- A good performance/price ratio
- Compatibility with our portable solar panels
In summary, we were looking for a reliable and high-performance battery kit to charge phones, power a light source, or supply electricity to our compression fridge, for example.
We are mindful of the environmental aspect and very particular about its safety/stability (as we literally sleep right next to the battery, it's better to choose a good product!)
The Product Selected
Among the numerous options, the EcoFlow portable battery kit is the one that won us over.
Its characteristics fit our needs, its multiple connections and the brand's approach appealed to us. Moreover, EcoFlow has been a leader in this field for over 10 years and, in our opinion, has numerous competitive advantages.
This compact and powerful product has a capacity of 768Wh and an output power of 800W. For example, it could power our compression fridge for 80 hours (*). It could also recharge around 24 smartphones for 8 hours each (**). For a laptop consuming 60W, it could be recharged by our auxiliary battery kit for more than 12 hours.
In addition to its large energy storage capacity, this EcoFlow river 3 max plus battery can be recharged to 100% without major degradation in just 70 minutes.
It is therefore possible to quickly recharge it, for example, while having a meal.
In summary, there are 4 recharge modes available:
- Via a solar panel (allow about 3.5 hours for a 220W panel)
- Via AC outlet / standard plugs (70 minutes)
- In the car (about 9 hours)
- Via USB-C port (about 9 hours)
For longevity, the battery kit we selected is well placed with a projected 10-year lifespan according to the brand. For this battery technology, the number of cycles is at least 2000 and can easily go up to 3500 cycles or even 6000 with optimal use!
Finally, this battery has the advantage of having a minimal size and weight compared to its competitors: 270x260x226mm for 7.8Kg.
Below is an explanatory video showing how the EcoFlow battery works and is used:
(*) : For the following data: internal fridge temperature: 5°C / ambient temperature: 20°C / fridge consumption: 0.75Ah/h.
(**) 768Wh/4W=192h and 192h/8h = 24 phones
Summary Table of Criteria by Technologies
Before examining the other available technologies on the market, it is useful to compare them in a table. This allows us to quickly visualize how our Li-ion Iron Phosphate battery kit ranks compared to others. This table summarizes our findings and is based on our research and tests.
Legend
| +++ | excellent |
| ++ | very good |
| + | fairly good |
| - | fairly poor |
| - - | very poor |
| - - - | lamentable |
| Battery Type | Safety | Power | Price | Energy Density | Lifespan | Self-Discharge |
|---|---|---|---|---|---|---|
| Li-ion Iron-Phosphate Batteries | +++ | ++ | + | ++ | +++ | ++ |
| Lead-Acid Batteries | - | + | ++ | - | - - | - |
| AGM Batteries | + | + | + | - | - - | - |
| GEL Batteries | + | + | - | - | + | - |
| Lead-Carbon Batteries | + | + | - - | + | + | - |
| Nickel-Cadmium Batteries | - - | + | ? | - - | + | - - |
| Nickel-Metal Hydride Batteries | + | + | - | + | - | - - |
| Li-ion Cobalt-Oxide Batteries | - | ++ | - - | +++ | - | ++ |
| Li-ion Manganese-Oxide Batteries | ++ | ++ | + | + | - | + |
| Li-ion Nickel-Manganese-Cobalt Batteries | + | + | - | +++ | + | + |
| Li-ion Titanate Batteries | + | + | - - | - | +++ | + |
| Li-ion Nickel-Cobalt-Aluminum Batteries | - | ++ | - | +++ | - | + |
| Lithium-Polymer Batteries | - - - | ++ | +++ | + | - - - | - - |
| Sodium-ion Batteries (under development) | ++ | + | ++ | - | - | + |
The Selected Technology:
Lithium-ion (Li-ion) Iron-Phosphate / LFP
Where does it come from?
Like any cutting-edge company, EcoFlow has chosen to use lithium batteries. Among this "family" of batteries, there are Lithium-metal batteries (research and development still ongoing) and Lithium-ion batteries.
Our river 3 max plus auxiliary battery kit uses this Lithium-ion technology. There are also several mineral combinations within this technology, each bringing its own advantages and disadvantages. An overview of other mineral combinations is provided below. The idea was to select the combination that best meets our needs.
We have therefore selected Li-ion Iron-Phosphate batteries, also known as LiFePO4 or LFP.
How is it made?
This type of battery is schematized below:
Positive Electrode (Cathode)
Negative Electrode (Anode)
PO4 / Phosphate
Fe / Iron
Li / Lithium
Separator / Polymer Membrane
Electrolyte
Carbon (Graphite)
On the left in the diagram, there is the cathode (+) primarily composed of phosphate and iron. This is the distinctive feature of LFP (Iron-Phosphate) batteries.
On the right, there is the anode (-) composed of carbon in the form of graphite. Unlike the cathode, this material and placement are relatively common across different battery technologies.
In the center, between the cathode and anode, is the separator.
One of the components, and certainly one of the most important, is lithium, which as we will see shortly, does not have a fixed position.
All the components mentioned above are immersed in a conductive bath called the electrolyte.
How does it work?
The principle is quite common across all accumulators. The one above (LFP) follows the same rules.
It works through an electrochemical reaction between lithium ions and the cathode and anode materials.
During charging, lithium migrates from the positive electrode (cathode, on the left) to the negative electrode (anode, on the right) through the electrolyte (which conducts). The reverse occurs during discharging. These internal movements within the auxiliary battery release electrical energy.
Obviously, the process is illustrated with chemical equations explaining, among other things, the electron movements during the reaction, but let’s not lose sight of the purpose of this page: finding a battery kit for a camper van.
With the principle understood, it’s now interesting to look at the advantages and disadvantages that come with this technology.
So, what’s the verdict?
This technology offers more advantages than disadvantages for vanlife and adventure-type use.
One of the most important advantages is its high thermal stability. In fact, on the market, it is currently one of the safest, with a much lower risk of explosion or fire compared to other battery types. The reason lies in the chemical process, which is simply less reactive than the others. Even under tough conditions (heat, shocks, vibrations...), this type of auxiliary battery is more durable and presents a low risk of damage.
In addition to this safety aspect, which we considered crucial, LiFePO4 batteries have demonstrated longer lifespans compared to other types like NCA batteries (mentioned in section 3.3). It’s worth noting that for some material combinations, the battery’s condition is greatly affected by a full 100% charge, but there are no significant issues with our type of battery. It is thus possible to take advantage of the 20% between 80% and 100%, providing a wide operating range. These many benefits have led major car manufacturers like Tesla to adopt this technology in some of their models (Model 3 and Model Y).
However, this type of battery is not the one with the highest energy density among Lithium-ion technologies. A security/performance compromise had to be made here. Nevertheless, it is still significantly better compared to the standard batteries found in most gasoline-powered cars.
info Average energy density of a standard internal combustion vehicle battery: 40 Wh/kg
info Average energy density of a Li-ion LFP battery (EcoFlow type): 180Wh/kg
Furthermore, although linking ecology/environment with batteries may seem contradictory, we opted for an auxiliary battery without Cobalt or highly polluting materials like Cadmium.
In summary, the LiFePO4 batteries we chose offer a very good balance between performance and lifespan, without forgetting their greatest strength: safety.
According to our research, experiences, and feedback, they currently represent the best technology on the market for mobile van, truck camper, or RV use.
Other Existing Technologies
Although lithium-based batteries are widely discussed today, they are not the only technology available. The first non-rechargeable cells appeared in the early 19th century. About sixty years later, the first rechargeable batteries were introduced. Since then, research and technology have continuously evolved to progressively replace (or at least reduce consumption of) petroleum. Below, in order of appearance, are the different other technologies that could have been used for outfitting a camper van during a road trip.
Lead Batteries
Lead-acid batteries are a relatively old technology but still widely used. These are the batteries found in most internal combustion engine vehicles, used to power the starter motor. Within the "Lead-Acid" family, four major technologies can be distinguished:
- Standard Lead-Acid Batteries, available in a wide range of sizes and capacities, they are affordable and standardized (commonly found in stock). This type of accumulator requires regular maintenance, and its lifespan is around 300 cycles. This is generally the type of battery found in gasoline-powered vehicles. Note that negative temperatures significantly affect the performance of this technology.
- AGM Batteries (Absorbed Glass Mat), often used in stationary applications or for private vehicles, these sealed batteries require no special maintenance and offer better safety (e.g., water resistance). Although their performance is slightly better than the standard lead-acid type, the prices are higher, and some issues remain (such as sensitivity to overcharging).
- GEL Batteries (Gel Electrolyte), similar to AGM batteries, these are better suited for heavy use. Additionally, their lifespan is improved, offering around 800 cycles depending on usage. As with AGM batteries, their price is higher, and charging performance is not their strong point.
- Lead-Carbon Batteries, an advanced version of lead batteries, offering better performance. Although lead batteries are generally expensive, this technology can handle high currents and is more resistant to sulfation. While present in renewable energy systems, the downside is the limited availability of this technology.
In summary, lead batteries (especially GEL and AGM) can be suitable for electrical systems in a van or camper. However, the term "installation" is used carefully here. For this type of battery, additional elements will be necessary, and an electrical plan should be created. This step should not be skipped, as improperly done DIY installations could lead to serious consequences. Note that these systems are generally not portable, so consider the intended use!
Nickel Batteries
Nickel-based batteries, which appeared in the early 20th century, quickly became an alternative to lead batteries. The commonly used name for this type of battery starts with "Ni-" for nickel, followed by the associated material. Among this category, two technologies dominate:
- Nickel-Cadmium Batteries (Ni-Cd), pioneers in using nickel, these batteries also contain Cadmium. This highly toxic material was banned in Europe in 2016. Only specific applications, such as military or medical use, continue to use them. This technology is obsolete for general consumers.
- Nickel-Metal Hydride Batteries (Ni-MH), replacing Cadmium-containing batteries. This technology is more "eco-friendly." It performs well at high temperatures and is less prone to memory effect. However, despite decent performance, this type of battery suffers from high self-discharge rates and poor performance at low temperatures.
It is easy to understand that this type of battery is not ideal for van/camper use on road trips. The first is no longer used for common applications, and the second has significant drawbacks. It is better to reserve this technology for more stationary uses or hybrid vehicles (e.g., Toyota Prius).
Lithium Batteries (Other than Lithium Iron-Phosphate)
Exploited since the 1970s, lithium has quickly become a material highly suited to energy storage. As we saw in the "2.1 Lithium-Ion (Li-ion) Iron-Phosphate / LFP Technology Used" section, there are several material combinations. Below, we present 6 major lithium-based technologies (different from Li-ion Iron-Phosphate - LFP) and our views on their suitability for camper van/camper or van use.
- Li-ion Cobalt-Oxide Batteries / LiCoO2 / LCO, an interesting technology because of its high energy storage capacity. However, it is primarily used in electronic devices like mobile phones or cameras (adequate autonomy). LCO technology is rarely used in auxiliary batteries for camper vans, and we decided not to pursue it due to the presence of Cobalt and the high prices.
- Li-ion Manganese-Oxide Batteries / LiMnO4 / LMO, often used in power tools or electric bikes. This technology offers "average" performance, with reasonable pricing. We did not choose this for our camper van conversion because of its shorter lifespan, between 300 and 700 cycles, which is the shortest for Lithium-ion batteries.
- Li-ion Nickel-Manganese-Cobalt Batteries / LiNiMnCoO2 / NMC / NCO, a competitor to LFP technology. It offers good advantages such as good energy density and acceptable weight. However, it contains Cobalt, and our stance on this material has not changed. It also requires careful usage (avoiding full 100% charges), which we find inconvenient. We prioritize minimizing constraints during road trips.
- Li-ion Titanate Batteries / Lithium Titanate / Li4Ti5O12 / LTO, promising batteries with excellent durability (between 8000 to 20000 cycles, according to some sites) and fast charging. However, they are not widely used at the moment and are mostly found in heavy-duty applications or forklifts. While their energy density is not huge, we could have considered this chemistry if the supply were more accessible.
- Li-ion Nickel-Cobalt-Aluminum Batteries / LiNiCoAlO2 / NCA, sometimes used in cars by certain manufacturers. They also present good energy density, good range, and high internal voltages. However, their lifespan is generally around 1000 cycles, and they contain Cobalt. Their stability and safety are average, which made us rule out this chemistry for our van conversions.
- Lithium-Polymer Batteries / LiPo / LIPO, derived from the previous Lithium-ion batteries, they are extremely compact (due to their special electrolyte) and powerful. However, their lifespan is very short, and they are unstable and dangerous. For these reasons, they are mostly used in model-making. It was clear that this technology was not suitable for our industry, which is why it was not prioritized.
In summary, there are many types of lithium batteries, and each one has its advantages for specific sectors. We had no strong preferences or influences regarding the choice of our auxiliary battery equipment, so the selection was made through a process of elimination. As we mentioned in the first section, some technical points are mandatory, such as:
- High thermal stability
- Good capacity
- Long lifespan
Now that we’ve covered the different battery types, whether Lead, Nickel, or Lithium, you are now familiar with the main solutions for energy storage. After exploring these battery technologies, let’s move on to other possible electrical setups.
Other Possible Installations
You may want something other than an auxiliary battery kit for your van conversion for reasons specific to you. Let’s discuss two other technical solutions for powering your van. The first one still attracts many vanlifers today, so we’ll weigh the pros and cons. The second, on the other hand, is more innovative.
DIY Installation
Below is an example of a DIY installation done in one of our large Combeing boxes.
Below is an example of an installation done in one of our half-sized Combeing boxes. With this configuration, elements like the separator coupler, for example, had to be moved under the hood for space reasons.
If you feel like becoming an electrician, there are a few things you need to know before getting started! Camper vans have existed for a long time, and portable batteries like our EcoFlow weren’t always available. It is therefore common to come across vans or camper vehicles with a DIY electrical system (which works very well).
In summary, if the goal is to convert your vehicle into a fully-equipped camper, it’s important to:
- List the equipment that will be used in the vehicle (Power in W, Voltage in V, Energy consumption in A/h, and estimated consumption time (in hours and days)).
- Sketch the installation before starting (where to place the fuse holder, switches, outlets, etc., considering the quantities).
- Size the materials: This is a crucial step for proper functionality and safety. The size of the cables and the fuses protecting your system must be dimensioned based on the electrical current flowing. If this step is done poorly, it could easily lead to a fire risk.
- Select the equipment: This includes purchasing the battery, coupler/separator, voltmeter (if you wish to monitor the battery’s condition), switches, outlets, fuse holders, MPPT for solar panels, etc.
- Properly install the system according to electrical standards to avoid endangering yourself, your equipment, or your vehicle. You can also seek advice from more experienced people to avoid mistakes!
DIY installation typically costs around 350-400€, which is slightly less expensive than most portable battery kits.
More installation examples in camper vans and vehicles are available below!
Here is a schematic electrical diagram illustrating the different components and their respective placements:
Coupler-separator
Additional auxiliary battery (in addition to the vehicle's main battery)
MPPT (device for managing the solar panel)
Control box (switches + fuse holder included)
Ecoflow Energy Kit Installation
Another more innovative solution has been developed by the brand EcoFlow. It is an evolution of the previous installation.
They aimed to combine all the components needed for proper operation (except for the batteries) into one single unit. Then, using just one cable, you can connect the battery or batteries to this unit. This relatively new technology greatly simplifies electrical installations and ensures much better safety.
As you can see in the image above, the system on the right is much simpler than the DIY installation on the left.
The product as a whole can be broken down into three major parts:
- The smart equipment (in 1)
- The consumption tracking equipment (in 2)
- The batteries (in 3)
This system is also fixed, meaning once installed in the camper van, it’s not designed to be disassembled after every use. It is highly efficient and adaptable to each person’s needs because only the number of batteries needs to be adjusted (no electrical plan reading required). The price is 3,898€ for the most economical system and 13,596€ for the Rolls-Royce of van electricity, with a 15kW power system!
Both of these solutions are functional. However, the portability of the EcoFlow river 3 max plus battery kit won us over. Just like our company’s ethos and the preference of most of our community, the modular and mobile aspect is crucial. The idea is to be able to move the battery outside if you want to be outdoors, by the pool, by the lake, or anywhere else. No constraints, simplicity, and practicality are what we wanted. Combining performance with its Li-ion Iron-Phosphate (LTO) technology, safety, mobility, and a good price-performance ratio, our choice was natural!
Battery and energy systems are a strategic development axis for many industries, which is why the evolution is so rapid. In addition to Lithium-metal batteries under development, a new battery technology called Sodium-ion is starting to emerge. Promising because of its abundant components (thus low cost), ecological aspects, and stability (safety), this technology could soon integrate into the general public once its lifespan or energy density issues are solved. Stay tuned!
Transform your utility vehicle into a camper van in 5 minutes.
Combeing is the ideal solution for owners of utility vehicles, vans, and campers who want to temporarily repurpose their vehicle for leisure in just a few minutes.
102 reviews
What our customers say...
Alain Martin
8 month(s) ago
Welcoming, very professional and competent team, very practical, functional and quality equipment, well done, great company, well-deserved stars.
salmandra x.
8 month(s) ago
I had put my kit in the basket. Sent an email with a question, Mathieu called me straight away, and even advised me on a better configuration. Appointment made 2 days after installation, with removal of my partition. And I was so well received that I added the kitchen module. A lovely, warm team. Go there with your eyes closed. I'll go back and do my insulation later... Thanks again... Sandra
Morane Barguillet
9 month(s) ago
We ordered our kit in September 2023 for our Opel Vivaro H1L2, we have used it well and made it profitable since. Received on a pallet with a very fast turnaround. A smooth and simple installation with several layout choices. We do not regret our investment. The materials after a year and a half are like new, you just have to take care of them. I recommend ??
Joel Joel
1 year(s) ago
5 stars well deserved. Great team A simple email resulted in a purchase. I felt considered, taken seriously and at the center of attention Once there, Matthieu was more than incredible. Really at the top. Knew how to satisfy, fulfill all my wishes. The family thanks you.
Hervé LOZES
1 year(s) ago
Ingenious and really well thought out concept, quality material and precision manufacturing, with a responsive team, I highly recommend!
Laetitia Coudrai
1 year(s) ago
We bought a Combeing kit a few months ago for our VW T5 transporter and we are very satisfied with it! Delivery was free and fast. Customer service is top notch, whether for information or responsiveness. The kits are adaptable to your type of vehicle but also to your use whether it is road mode, night mode or day mode (with table). Very good value for money. We highly recommend. And a big thank you to Mathieu for sending goodies!!
Laurent Gréco
1 year(s) ago
A great team, a high-quality product, a very competitive price. We sold our converted van because our annual usage time did not justify such an expensive investment. We bought a utility vehicle that we converted to our taste with the possibility of modifying its configuration according to our needs following the many very professional tips received from COMBEING. The team took the time to welcome us into the company and to assemble our modules in order to have a tailor-made layout with everything necessary to live independently: gas, water point, electricity, toilet, solar panel, shower... In short, everything necessary to live pleasant moments according to our desires without having to have our vehicle approved in VASP. Thanks again to the whole team for their welcome, their availability and their professionalism which really deserve to be highlighted
Domie Palet
1 year(s) ago
Very satisfied with the modules, fast delivery, a super friendly team, thank you Mathieu for his advice and his professionalism, the best!!!! We recommend without moderation...
Johann Manassian
1 year(s) ago
Really great, the team is really cool, the products sold (sports kit for VW T6 for me) are really great (but I didn't doubt that, I had already planned everything thanks to their website, but with their advice I made some changes that suit me better). I also did the sprayed cork insulation before going to get my kit, super simple and beautiful rendering. I really recommend more than ever. Thank you and good luck in your new premises.
caroline faure
2 year(s) ago
5 stars without hesitation for this professional company for the modular fitting out of Vans and Campers. Special dedication to Mathieu, who was able to listen and find all the solutions to my constraints while respecting my budget! The team is great, the atmosphere friendly! I recommend!!
Laurent FOUCHARD
2 year(s) ago
I was looking for a van that could be used as a daily, utility or leisure vehicle and with the Combeing Full kit, I found exactly what I wanted for my L1H1 van. I spoke several times with Mathieu and Raphaël, their listening, their responsiveness and their availability as well as their advice and services were very valuable in guiding me in my choices... In short, very well-made kits, easy and quick to set up, as well as a great team mean that I highly recommend this friendly company...
Stephane Picard
2 year(s) ago
We made an appointment, Mathieu welcomed us warmly and showed us around the workshop, then we went to the selection area to recap and make the quote. We had all the necessary technical explanations as well as his advice and feedback. The guy is sincere and super professional. Our choice validated, he helped us throughout the time needed to set up the modules. Again, lots of advice and tips, thanks to him. I thought the idea was absolutely brilliant on paper but it's even better in the van, the possibilities are endless, the quality is great, everything is thought out down to the smallest detail. In the end, it confirms that with my 1m70 we can sleep across without any problem and therefore keep the table in place during the night. Conclusion: we are satisfied beyond our expectations. Thank you COMBEING, thank you to the brilliant inventor and thank you Mathieu for your advice
Our strengths & values
No VASP approval required
Shipping within 48 working hours
Come and leave with your kit
Local and artisanal production
Low ecological impact
Professional integration (ESAT)
Infinite combinations to suit your wishes
Our kits adapt to all types of vans. Combeing selects the appropriate floors for your utility vehicle; you will just need to move the boxes around on this floor as you see fit. In just a few seconds, switch from a configuration with a table and seats to a large bed that covers the entire interior of the vehicle.
