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For those looking to enjoy the conveniences of modern life while camping off the grid, the right house battery for your campervan is essential. A battery that can power your lights, fan, fridge, technical gadgets, and other electronics is a must-have for many living in their vans, full or part-time.
A campervan needs two batteries: the starter battery in the engine and a house battery to power electronics and appliances. The size of the house batteries required is determined by the electrical needs inside the campervan.
In the rest of this article, we’ll explore the second battery you need for your campervan in more detail. We’ll see the different kinds of batteries available and how to calculate the best size for you. We’ll also explore how to recharge this battery while on the road.
Understanding the House Battery
While your campervan will come with a battery that starts the engine, you’ll need a secondary battery to power the home part of your van. The starter battery is the name given to the one in the engine.
The house battery is the battery giving power to your lights, fridge, computer, phone charger, fan, and other electric equipment. It’s typically located in the back of the van, but its exact placement is up to you.
To help you choose the best house battery for your needs, we’ll examine a few different components.
First, we need to see how much energy you’ll consume and what size battery makes the most sense for you. Second, we’ll go over the different types of batteries and discuss which will work best for your van.
Understanding Amp Hours
Understanding your campervan’s battery needs is an important part of van life. Before we can choose the best battery for the van, we have to understand the numbers and ratings used to express a battery’s performance.
Amp-hour ratings are useful to understand how much current a battery can provide each hour. Your battery will have an amp hour rating, and you can use this number to understand how many of your appliances your battery can power.
For example, you might see a 12-volt battery that has an amp hour listing of 200. A basic understanding of these numbers tells us that for an hour, we can support a 12-volt load with 200 amps of current.
However, these numbers will change depending on the kind of battery. If it’s a lead-acid battery, you should divide the number of amps in half. So, you would only get 100 amps of current with a lead-acid battery for the same example listed above. That is because otherwise, you’ll severely damage your lead-acid battery.
Of course, the lower the amps needed per hour, the longer your battery will last. The number of amps multiplied by the number of hours gives you the amp-hour rating shown on your battery. This rating is key in understanding both how much energy your appliances consume as well as how much power your battery can give.
If you don’t see an amp-hour rating but see watt-hours, don’t worry. Watt-hours are a similar rating system that you can easily use or convert to amp-hours.
Watts is a measurement of power and is calculated by multiplying the voltage with the current. Watt-hours are calculated by multiplying the voltages by the amp hours. For example, the 12-volt 200 amp-hour battery we saw above would have 2,400 watt-hours
Understanding Your Power Needs to Know How Many Batteries your Campervan Needs
To better understand this topic, let’s take a look at some typical energy usage in a campervan.
Let’s consider your roof vent fan. While you can check with the manufacturer to see how many amps it’s pulling at different settings, let’s look at an average.
Suppose the fan is pulling 1 amp per hour of use, and you use the fan for 6 hours a day. This means that your daily fan usage is equal to 6 amp-hours (1 amp x 6 hours = 6 amp-hours).
You’ll want to continue these calculations for all of your items, summing up the total number of amp-hours.
However, this method is best if everything runs on the same voltage. If not, it’s better to calculate in terms of watt-hours. For the above example, if the fan runs at 12 volts, you‘ll multiply 12 by 1 to get 12 watts. Then, 12 watts times 6 gives you 72 watt-hours.
Whether you calculate your usage in amp-hours or watt-hours, make sure you’re consistent for all of your items.
Once you understand the items you use regularly and how much power they draw, you may consider running the numbers for different weather. Making estimates based on different seasons can help you understand the full range of your potential energy usage. Renogy created the [sherpa id=”068f9859″], a great tool to estimate your power consumption and better plan your solar system.
For example, your refrigerator will be actively running more hours during the day during hot weather. When the outside temperature is so different from the inside of the fridge, this appliance will have to work hard to regulate itself.
During winter, when the outside temperature is closer to the fridge’s internal temperature, it’ll not have to run for so many hours actively. This fluctuation will impact your overall energy usage and battery needs.
To help you understand how much power they’ll be pulling, watch this Youtube tutorial:
Understanding Battery Size
Once you understand your unique power needs, you’re ready to see what batteries are suitable for you and your van. 60 amp-hours of daily usage is a typical number when considering standard appliances and power needs.
Using this example, let’s see what battery might be suitable.
Suppose your van needs 60 amp-hours per day to run all of your required items. If you choose a 100 amp hour battery, your depth of discharge will be around 60% and your state of charge around 40% by the end of the day. These numbers mean that every day your battery is discharging over half of its power.
If you have a lead-acid battery, you don’t want your battery to drop below a 50% state of charge. For this example, a 100 amp-hour battery isn’t sufficient for your particular van needs. It would discharge too much each day, severely damaging your battery over time. However, a 100 amp-hour lithium battery would be fine to cover your daily needs.
Let’s consider a 200 amp hour battery. Now, your depth of discharge will be around 30%, and your state of charge around 70%. No matter if you have a lead-acid or lithium battery, you can run all of your appliances on a 200 amp-hour battery without dipping down too low in your state of charge.
Now, you’ll want to consider how long you want to go without recharging your battery. The length of time you can go without recharging will depend on the type of battery you have chosen. For example, a lithium 200 amp hour battery will give you two days without recharging. If you use a comparable lead-acid battery, you’ll only have approximately one day before you’ll need to recharge
If you’re looking to go a few days without needing to recharge, you’ll want to consider a larger battery. You can look to a 300 or 400 amp hour battery to last longer out on the road.
However, if you expect to be in sunny places where you can use your solar panels each day, you may feel comfortable with a smaller battery. It’ll depend on your style of camping and how often you’ll be connecting to your energy sources.
Additionally, if you’re using solar, you likely won’t reach the full depth of discharge that you’re calculating for. If it’s a sunny day, your batteries will be charging as you use your appliances.
Lithium Versus Lead-Acid Batteries
When choosing batteries, it’s also important to understand the main kinds. The two main categories are lead-acid batteries and lithium. These are completely different when it comes to their usability, lifespan, and pricing. Understanding the differences will help you make the best choice for you and your van.
How Many Lead-Acid Batteries does your Campervan Need?
Lead-acid batteries are the older of the two and have been widely used for decades. Most cars will have one of these batteries under the hood.
These are on the larger and heavier side but are generally the cheaper option. However, in the long run, they’ll likely not last as long as their lithium counterparts.
On average, a lead-acid battery will give you about 50 to 100 cycles of charge. This is much less than the thousands of cycles a lithium battery may give.
If you do choose a lead-acid battery for your camper van, you must choose a deep cycle version.
Lead-acid batteries come in two varieties:
- deep cycle
- starter
The construction of these batteries is different, and you’ll need the deep cycle in order to access more power during use.
Even when using the deep cycle battery, you still have to be careful about how deeply you discharge your battery. These batteries should always be kept at 50% charge. If you discharge more deeply than this, you’ll significantly reduce their lifespan.
This means when looking at the rated capacity of a lead-acid battery, you’ll need to divide it in half. For example, a 12-volt battery with a listed 200 amp hour rating will really only yield 100 amp-hours in practice.
The more deeply you discharge your battery, the shorter its lifespan will be. For example, if you’re using 50% of your battery’s charge each day, it’ll wear out sooner than if you’re only using 25%.
How Many Lithium Batteries do your Campervan Needs?
Lithium batteries are a much more recent innovation and can commonly be found in our phones, laptops, cameras, and other gadgets. These are powerful batteries that have really taken over in recent years.
One of the appealing things about lithium batteries is their energy density, which is higher than that of lead-acid batteries, meaning that they store more energy in a smaller and lighter container.
Another great perk of lithium batteries is their depth of discharge. Unlike lead-acid batteries, you don’t have to worry about keeping these batteries halfway charged at all times. You can fully discharge these batteries each day without causing significant damage.
This means that if your battery has a listed rating of 200 amp hours, you have access to that full amount of current for the day. You don’t need to divide by two like you would with a lead-acid battery.
These batteries will recharge quickly and have thousands of cycles of charge in their lifespan.
However, these batteries are more sensitive and will require a battery management system. This will help your battery stay in acceptable ranges when it comes to current, voltage, and temperature. Luckily, most lithium batteries will have a battery management system built into the construction of the battery itself.
For more information about these two battery types, you can watch this informational video on Youtube:
How to Recharge Your Campervan Batteries
As you make decisions regarding your battery and your van’s electrical system, you’ll want to consider what you can install to help recharge your battery on the road. A few different systems in place are best, but at the very least, you’ll want one solid option to fall back on.
Your van may come with a gas generator and a shore power hook-up. The gas generator isn’t a good long-term solution if you’re looking to be fully immersed in the van life experience. Generators are noisy and go through a lot of fuel when running. This isn’t the best option for someone looking to live full or even part-time in their van.
Solar Energy
Related Guide: How Many Solar Panels Do I Need for My Van?
To be more prepared for off-grid camping, you’ll have to make some adjustments to your van yourself. Many people choose solar power as their number one recharging method. It’s a great choice, as it’s a renewable energy source that can be easily harvested during the day.
After the initial purchase and installation of your panels, you’ll be pulling free and clean energy each day that you park your van in a sunny spot. As many people use their van to get out in nature, it can be quite easy to find an open space each day with plenty of sun.
Installing 300 watts worth of solar panels will meet the average needs of your van. You can do this by purchasing a few smaller panels or purchasing one larger one that meets all of your wattage needs. You’ll want to install these on the roof of your van, where they’ll get direct, strong sun each day.
You’ll want to consider how to mount your solar panels on your van. Solar panels are most efficient when they’re installed at an angle since they’re perpendicular to the sun’s rays. This positioning will harvest the energy most effectively.
However, this positioning isn’t very conducive to the roof of your van. Most people choose to place the panels flat on the roof of their van.
While it’s less efficient in terms of energy harvesting, it makes the most sense aerodynamically since your van is a moving vehicle. Your solar panels will be safer in the long term if installed flat.
If you do install your solar panels flat on your roof, simply keep in mind they may not pull the maximum listed amount of power. You’ll also need to install a solar charge controller to take the energy from the sun’s rays and convert it into an energy form that can feed your battery.
Many of these charge controllers have exciting features that let you know exactly what’s going on with your energy usage. Many will have apps you can use to see how much energy you have collected during the day and how much is going to your battery.
Alternator
Even if you install and are happy with your solar panels, you’re bound to run into some cloudy and stormy days where you can’t recharge. In that case, you’ll want to have another option ready to charge your battery and keep your van appliances running smoothly.
You can hook up the alternator of your van to charge your battery as you drive. The alternator is taking the engine’s rotational energy and converting it into electrical energy. This energy is typically used to keep the starter battery charged and happy.
The alternator is only producing electrical energy if the engine is running. You want to be careful that you aren’t drawing too much energy from your alternator, as this can stress your alternator and cause it to burn out.
You can install a new alternator that’s capable of carrying more current. The factory-installed amp may not be enough for your electrical van needs. If so, you can purchase a larger alternator with a higher amp rating to better suit your electrical setup.
When connecting your alternator to your ‘house’ battery (not your starter battery in the engine), make sure they aren’t connected directly. You can use an isolator or a battery-to-battery charger to connect the two batteries together.
AC Charger
You may also choose to equip your van with a 120-volt AC charger for when you have a chance to plug into an electric source. When you come upon a normal outlet, you can use an extension cord to plug in directly. This can be another good backup option for battery charging. This kind of charging is also referred to as shore power.
For more details on setting up alternate charging sources, you can check out this detailed Youtube video:
Other Tips for Your Battery Set-Up in your RV/Van
Setting up your van’s electrical system may seem intimidating if you don’t have much experience. However, more and more people are successfully converting camper vans and creating their own successful electric setups that connect all the necessary parts. Let’s take a look at a few additional tips to keep in mind.
Know Your Categories
One way to help your electric setup is to think of all the components in distinctive categories. First, consider your charge sources. This includes your solar panels, alternator, and AC Charger. Next, think of your house battery and the components that receive and spread the energy as necessary.
Finally, think of what will be consuming energy. You can divide this category into two parts:
- DC circuits
- AC circuits
Setting Up Your Battery
On your house battery, start with the positive terminal. This is where you’ll attach the biggest fuse of your system to keep you and your battery safe in case of an emergency. Everything else that needs to attach to the battery’s positive terminal will be attached after the fuse.
Once the fuse is attached to the positive terminal, you can install a system switch. This is a handy device that allows you complete control over the power from your battery. You can switch it on for day-to-day use and switch it off anytime you need to perform maintenance or need to shut the system down.
On the negative terminal, you’ll want to install a shunt and a battery monitor. The monitor is the perfect way to keep your eye on the voltage and the current going in and out of the battery at any time. Depending on the model, it might also be able to tell you how many amp-hours were used since the last time it was fully charged, among other useful bits of information.
What is most important about the battery monitor is its ability to read the battery’s state of charge. Being able to see immediately how charged your battery is at any time is key.
- Built-in Bluetooth Communication - Monitor your batteries on Apple or Android smartphones, tablets, macbooks, and other devices
- Easy to Install - The shunt interrupts the negative coming off the battery bank connects to the monitor with a standard RJ12 telephone cable.
If you’re looking for a recommendation, you can try this Victron Energy Battery Monitor available on Amazon.com. This has a display that is easy to read and Bluetooth capabilities, meaning it can easily be linked to your phone, tablet, or other smart devices.
Next, you’ll want to connect to a safety hub. This is a component composed of several fuses and positive and negative bus bars. You can connect between the safety hub from your system switch on one side and from the shunt on the other.
From the safety hub, you’ll connect both your charge sources as well as the consumers of your energy.
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Connecting Your Charge Sources
As you install and connect your solar panels, you’ll need an entry gland in order to transition these cables from the roof of your van to the inside. You can check out these Link Solar Waterproof ABS Double Cable Entry Glands, available on Amazon.com. These entry glands are well-made, will fit most round cables, and can easily be sealed tightly to the roof of your camper van.
From here, the negative connection from the
From the charge controller, you can connect to your safety hub. You have now made a full circuit between your solar power source and your battery.
Another set of connections will come from the starter battery. This will connect the alternator to the house battery through a series of steps. The positive connection from the starter battery goes through a fuse, then a switch, and then on to the battery-to-battery charger.
Using the negative side of your starter battery, you’ll want to ground your whole system. Using a heavy-duty wire, you’ll connect from the negative side of the starter battery directly into your negative bus bar in your safety hub. This connection will ground your system to your vehicle’s grounding.
Remember, as you install switches for each of your energy sources, you have complete control over which source will charge your battery. You can switch them on and off as needed.
Connecting the Energy Consumers
Now it’s time to hook up your DC loads and AC loads. Your DC loads will likely be your lights, roof fan, refrigerator, charging stations, and other appliances and gadgets. It’s best if the majority of your energy consumption functions with a 12 Volt DC connection, as it’s easier to generate than AC.
You’ll need a DC fuse box that will go between your safety hub and your appliances. From the fuse box, the negative connection can be connected directly to the corresponding bus bar. However, the positive side must first pass through one of the fuses in the safety hub. It can then be connected to the bus bar.
By making this connection properly, you’ll be protecting both your cabling, your DC fuse box as well as your appliances. This is important to avoid melted cables or potential fires in your van.
If you do need 120 volt AC power, you’ll need an inverter. This piece of equipment might be necessary depending on the kind of laptop charger you have. Luckily, once you have the inverter, you can connect it directly to the positive and negative bus bars of your safety hub.
To watch a fully guided tutorial on how to set up your van’s electrical system, you can check out this Youtube video:
Final Thoughts
If you’re converting to your campervan for part-time or full-time living, you’ll need a starter battery for the engine as well as a house battery. Before selecting the kind and size of your house battery, you’ll want to take an inventory of your estimated energy usage.
Be sure to select a battery that you can comfortably use according to its state of charge guidelines. Remember that lithium batteries can discharge completely while lead-acid should always be kept at a 50% state of charge. These guidelines will help you find the perfect house battery.
