The Off Grid Camper.
In this article we will explore how to make the most out of your “off grid” campervan or RV electrical system. It is important to know how your system works and what you can do to improve the effectiveness of your system. We will review how much battery you need and how to charge the batteries and also, how to use the stored power to its fullest potential. We will also make product recommendations based off of years of our electrical experience.
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Terms to know:
Off Grid - This is a term that often gets misunderstood but is truly a simple concept. To be off grid is to sustain a living system that is not connected to or served by a public or private utility. For reference a residential home that is connected to a power utility, public water, or city gas is considered to be on the grid.
Boondocking - This term refers to campers who travel to public or private land and are able to sustain themselves without any outside resources, such as water, electricity, or bathroom facilities.
Shore Power - A term that many people use to describe a utility hook-up, usually in the form of a 120/240v AC outlet ranging from 15-50 amps. The shore power is often desired to use large appliances because it is a practically unlimited source.
A brief overview of an Off Grid System.
While traveling full time in our campervan, we never had to plug into shore power or use a generator. We had to first developed a design to make sure our off grid charging sources supplied our battery with enough power for all of our adventures. We used efficient appliances and learned to manage our power in a way that was completely sustainable. Now it’s time to share how we did it.
While living off grid in your campervan, you do not have an unlimited amount of power as you might have in a typical residential home. You will be relying on your batteries to store enough energy until you are able to charge them again.
The size of your battery bank is going to determine how long you can go before you need to charge them again, but batteries are very expensive, can be heavy, and take up lots of space. For this reason, we always encourage to base the size of your battery bank on what you will be using and how long you will be using it for. We always recommend Lithium batteries for use in a camper’s electrical system because they are the lightest, most energy dense, and most cost effective battery chemistry on the market. The Battle Born 12v 100AH Lithium Battery is a popular battery we feel confident installing.
We often tell people to look at your electrical system as a budget, if you don’t want to go broke, you need to contribute more than you use. We have found in our experience, that 200-400AH is a great place to start if you have a good design, and a working knowledge of your system. During the summer we were able to boondock for 7 days with out moving the van. The key to avoiding a unnecessarily large battery bank is to have well designed charging sources. This can include solar panels, alternator charging, or even a generator.
How to charge your batteries in a Off Grid Camper.
Solar Power.
Our number one charging recommendation is to maximize solar panels in an off grid electrical system. It is a relatively inexpensive investment and will produce free, clean energy for decades. Its pretty simple, if you are parked in the sun, your batteries will be charging. We know that space is precious and often other equipment such as fans, air conditioners, and antennas need to be mounted on the roof but we encourage using any available space to fit as many solar panels as possible. We find the amount of solar needed for an off grid campervan is about 200W-400W and around 1000-2000W+ for a RV.
Our goal is to install the highest quality off-grid systems possible and we find that RICH Solar provides the best variety of UL Listed solar panles on the market. In our experience we have found that the 200W solar panel is the most popular and versatile in RVs, while the 150W panel works great for a smaller campervan roof.
One thing to know about off-grid solar power is that you cannot simply connect a solar panel to a lithium battery system. Because of the nature of how solar panels work you will need a device that will properly charge a lithium battery, this is called a solar charge controller. The charge controller’s job is to take a solar panels unregulated voltage and convert it to a proper charging profile for a battery system. Without this device you run the risk of over charging, damaging, or destroying your new lithium battery investment. Solar controllers need to be specifically designed and programmed for every individual solar panel array but we find that the Victron 100-50 MPPT Solar controller is one of the more popular sizes we install.
Alternator Power.
Another great way to charge your camper without plugging in is to utilize the alternator of the vehicle to charge your batteries. This is a great option if you have run out of roof space, or are a very active traveller. The process is done by taking energy created from the vehicle’s engine and converting it to usable power to charge your electrical system. You can think of it as a small generator that is normally charging your starter battery and you are going to use some of that power to charge the camper’s lithium battery. This is a safe and guaranteed power source whenever you are driving and can be an excellent substitute if solar power is not readily available, like on a rainy day. You cannot directly connect the campers battery to the alternator, rather you will need a device that will properly regulate the voltage and amperage (just like a solar charge controller). The Victron Orion DC-DC charger is a great option to ensure you are not damaging or over drawing from the vehicles alternator and ensuring the campers batteries are charging correctly.
Generator Power.
While we did not incorporate a generator into our personal design, it is still a popular option among those who travel. When we install electrical systems that include a generator, it is usually because the RV is already equipped with one, or the electrical draw is too large for a battery bank alone. You can understand a Generator as an “off grid” shore power. You plug your camper into it just like you would a campground receptacle. Commonly, those who want to boondocks, or travel off grid in warm temperatures for long periods of time with air conditioner use will need a generator for supplemental power. The difficulty is to have a electrical system large enough to support a electrical load, like an air conditioner for 10+ hours a day. The balance is in how fast you can charge your battery bank. Some limitations could be based on how much roof space you have available for solar charging, or how often you are running your alternator charger. We have designed and installed many systems that incorporate off-grid air conditioning but often utilize large solar arrays, large battery banks, and upgrading the HVAC system for increased efficiency. For those looking for longer boondocking trips without air conditioning, we find that a small inverter generator like the Honda EU2200i works great for topping off the batteries in extreme conditions.
Now you have a brief understanding of how an off grid system is charged, it’s time to consider how you will be using the power you’ve stored. Everything from lights, to charging laptops, to using a blender takes power. Lets find out how to use the energy stored in your batteries efficiently.
How to use the power you have available.
Any appliance that is connected to the battery is going to draw power. Power is described in watts (W) and is an important concept in an off grid system. To give you a general understanding of wattage, here is a list of common appliances and their respective power consumption.
SMALL APPLIANCES
A Single 12V Puck Light has a power draw of about:
2 WATTS
A typical smartphone charger has a power draw of about:
20-40 WATTS
A typical laptop charger has a power draw of about:
100-150 WATTS
A typical DC powered Refrigerator has a power draw of about:
70 WATTS
A Typical Maxxair fan has a power draw of about:
60 WATTS
A typical gas/desiel heater has a power draw of about:
70 WATTS
LARGE APPLIANCES
A typical 120V countertop blender has a power draw of about:
1200 WATTS
A Typlical 120V Elctric tea kettle has a power draw of about:
1500 WATTS
A Typlical 120V Induction cooktop has a power draw of about:
1800 WATTS
A Typlical 120V Rooftop Air Conditioner has a power draw of about:
1500 WATTS
A Typlical 120V Hair Dryer has a power draw of about:
1800 WATTS
As we design a system we look at these numbers and how long they will be used for to determine how much power you will be using on average. A simple rule of thumb is that: if you use 1200 Watts for one hour, you will have used up an entire 12V 100AH Lithium Battery.
One major consideration in an off-grid electrical system is the difference between
12v DC and 120v AC.
120v AC is the voltage used in residential homes in the United States. Most of the appliances we use day to day plug into a 120V wall outlet.
The difference in a campervan is the battery voltage is often 12-24V DC which is not directly compatible with 120v AC.
This leaves us with two options..
Get new appliances that operate at 12-24V DC. The advantage of this option is efficiency. When your battery is the same voltage as your appliances there is nothing complicated you must do to accommodate a change in voltage and there are no inefficiencies.
OR
We can convert 12v DC to 120v AC, and this is where the inverter comes into the picture. For most off-grid electrical systems an inverter is usually recommended, but we try to keep its use to a minimum. When changing voltages there is always an efficiency loss. In our installations we use high quality products such as the Victron Multiplus.
The Victron inverters have about a 93% efficiency rating which is an industry leading number. In our experience the most popular option is a 3000W Inverter/Charger for use in an off grid camper or RV.
Victron 12V 3000VA Multiplus
Our most popular sized Victron Inverter/Charger
Inverters are sometimes required because you can not find an appliance that is made for 12v DC, some examples may be a specialty cooking appliance or a medical device like a CPAP.
One thing to understand about inverters is their ability to draw huge amounts of power from the battery bank. Inverters are usually involved in supplying power to larger electrical loads like an air conditioner or and induction cooktop. These types of electrical consumers should be limited as much as possible in an off grid system because they will drain the battery power very quickly.
We have written an in depth guide on the Victron Multiplus and its benefits.
Putting it all together.
Lets review the basics of an efficient off grid camper. First, we look at what you are using and how long you want to use it for, this will determine the size of your battery bank. Next, we need to determine the amount of charging needed to bring your battery bank to a full charge in an appropriate amount of time, this will vary greatly depending on your personal goals, but we find a 200ah of lithium is a good place to start.
When choosing the appliances used in the camper, we are looking for maximum efficiency. This is achieved by matching the operating voltage of the appliances to the battery voltage. For example, purchasing a 12v refrigerator instead of a 120v model will use your battery power much more effectively.
And lastly it’s important to reduce large electrical loads when camping off grid. Appliances like air conditioners and induction cooktops draw hundreds of amps from the battery and use up power quickly. Consider using alternative sources of energy for cooking and heating. We personally choose to use propane, primarily for cooking, in our van. A 20lbs propane canister would last us for 2-3 months before having to change it. For heat, we used a Webasto heater that connected directly to the gas tank, eliminated the need for carrying extra fuel. On a very cold day it would only consume about a gallon of gas to keep the inside of the van comfortable.
We travelled full time through the summer without an air conditioner by simply moving to climates with high temperatures around 75°. This allowed us to stay comfortable during the day without A/C and sleep through the night with little need to use heat. If you plan to use an air conditioner off grid, you may need to carry a generator or have an extremely large battery bank to support the large amount of power needed.
Managing power in an off grid campervan is a learned skill but it doesn’t have to be difficult. If you can understand your electrical system and effectively use your battery power then you can stay out adventuring as long as you want. Let us know in the comments if there is anything that you want to know more about!
