A Motorhome & Campervan inverter is a device that transfers the DC power from your motorhome’s battery to AC power that you can use to power your appliances and electronic devices. This is a good device to have if you plan to travel in your campervan, especially if you have to power any large electrical appliances, such as a refrigerator.
When you first get your campervan or motorhome one of the first things to learn is that you won’t be able to use the electric sockets just like you would at home, most electrical systems run on 12v and you will need an inverter to change the power from 12v to 240v.
Quick Links
There are two main types of inverters that you can buy. There are pure sine wave inverters and modified sine wave inverters. Pure sine wave inverters are more expensive, but also more reliable than modified sine wave inverters. Modified sine wave inverters are cheaper but more prone to failure and can end up damaging your appliances.
Keep reading to find out all about inverters for campervans/motorhomes, how they work and what we think are the best ones.
What Do Inverters For Campervans/Motorhomes Do?
There are a lot of electric devices that need 240v of AC power in order to run. When a motorhome gets plugged in to shore power, you are using the cable to give your motorhome a source of 120v of AC power.
The problem is that the battery in your motorhome only provides 12v of DC power. This means that when you are relying on your motorhome’s batteries for power, you need to have an inverter to convert the 12v of DC power into 240v of AC power.
If you do not use an inverter in your campervan, you may have to run a generator outside in order to power your motorhome. This is fine and a lot of people choose to do it, especially if they have an older motorhome that does not have as much power as a larger one.
Running a generator might not be an option for you, however. You might be somebody who works from the road for example. You also might simply just not want to hear the drone of a generator running all night. If this is the case, you need to get a motorhome inverter.
What Is the Best Size Inverter for a campervan?
Do you know what appliances and electronic devices you plan on running? Do they need to be running at the same time? You should try to strategically plan your appliance use to avoid overwhelming your inverter. The size of the inverter that will work best for your motorhome depends on your specific needs and the capabilities of your motorhome.
- Calculating How much Power
The best thing to do is work out what items you might be using for your inverter, for us its mostly our laptops, blender, and projector,
Hers is a rough list of the different items we use and the power
- Macbook Pro Laptop – 302w
- Nutribullet blender – 600w
- Viewsonic Projector – 140w
- Dyson hairdryer – 1600w
Something else to think about is using items at the same time, it’s not best to use the blender and hairdryer at the same time as this could make a huge surge on the inverter and cause it to crash.
account for this when you are thinking about how much power your inverter can handle.
E.G – A microwave can use move than 2000w when it first starts up and would require a big inverter and a bigger battery bank but we will come onto batteries next
Most likely, your inverter will be able to handle short surges in power. You should carefully read the instructions however to know exactly what your inverter can power and for how long.
Some manufacturers will list continuous power rating for the inverter size as the maximum rating. It is only in small print that the inverter can only handle a much smaller amount of power for a long period of time.
The key to finding the best size of inverter that you need is to add up the wattage of all the devices you want to power, and the surge requirements for all of these devices. Once you have calculated this total, you should add another twenty percent to it to make up for any extra loads on the system.
2. Battery Bank Capabilities
How big is your battery bank? This is another important factor to consider. If you only have a single battery or a small battery bank, you will not be able to use your inverter for very long. The smaller your physical battery bank, the smaller your inverter will have to be.
This is what most people don’t take into account, inverters use a lot more power than your typical 12v system so ensuring your have enough stored power is vital,
We recently had leisure batteries upgraded to lithium batteries, for this reason, we were just running out of battery power when working from the campervan.
If you need more information read our post – Best Motorhome Leisure Batteries
Let me explain using the following example.
A 1000w inverter can power your campervan for one full hour before it is completely drained,
but if you use only 100 watts of output power, from that same amount of energy source then this time will be reduced significantly – down to just over an hour!
This comes about because batteries discharge faster when they’re being used heavily and have less capacity left in them than expected due to the fact there are actually two separate components involved:
each cell within a battery has its own temperature and voltage drop off level which must add together to calculate how strong electricity should ever get at any given moment;
A 100ah battery can run a 1000w inverter at full power for 1 hour before it is completely drained. This is calculated by using the following equation:
Inverter watt load/volts = amps per hour
Then:
Battery size/amps per hour = runtime
A 1000 watt inverter / 12v ((typical camper van system) = 83.3 amps. So a 100ah battery should be used to allow for inverter inefficiency.
Then:
100ah battery/83.3 amps per hour = 1.2 hours. Batteries discharge faster when more amps are drawn so this will likely be more like 1 hour.
Inverter sizing guide for appliances and gadgets
| All Figures are in W | Power Rating of inverter |
| Equipment | Power Consumed | 300 | 600 | 1000 | 1500 | 2000 | 3000 |
| Smart Phone | 5 | / | / | / | / | / | / |
| Tablet Charging | 5 | / | / | / | / | / | / |
| TV | 33 | / | / | / | / | / | / |
| Laptop | 60 | / | / | / | / | / | / |
| Sound System | 100 | / | / | / | / | / | / |
| Games Console | 150 | / | / | / | / | / | / |
| Travel Iron | 700 | x | x | / | / | / | / |
| Travel Kettle | 750 | x | x | / | / | / | / |
| Vacuum Cleaner | 900 | x | x | x | x | / | / |
| Coffee Machine | 1000 | x | x | / | / | / | / |
| Microwave | 1100 | x | x | x | x | / | / |
| Toaster | 1200 | x | x | x | x | / | / |
| Hairdryer | 1400 | x | x | x | x | / | / |
You can also use this website – energy calculator
How Long Will a 12v Battery Last with an Inverter?
How long your 12v battery will last with an inverter depends on the size of the battery, the inverter that you use, and how many devices that you are powering.
You also have to consider the fact that your inverter will draw some power from your battery automatically, even if you do not have any devices or appliances plugged into the inverter.
The math to calculate how long a 12v battery will last with an inverter is pretty simple. You just need to multiply the battery amp hours (Ah) by twelve to calculate the number of Watt hours.
Then you divide this by the number of load hours to find out the total number of hours that your 12v battery will last when you are using it with an inverter. You should then multiply this by 95% to adjust for any energy losses with the inverter.
Should You Leave Your Inverter Running All the Time?
This depends on what you need to power. For example, if you have something like a refrigerator that needs to be on all the time, you should probably try to keep your inverter running all the time so that your food does not spoil.
A lot of people who have residential refrigerators in their motorhomes prefer to leave their inverter on even when the motorhome is plugged in to shore power or a generator. This is because they want a backup and do not want to risk their food spoiling due to a power blackout or generator malfunction.
How Does a Motorhome Inverter Work?
The difference between Direct Current (DC power) and Alternating Current (AC power) is that DC is a constant stream of power while AC shifts up and down between +120V to -120V in a rhythm.
The power inverter on your mobile home changes 12V of DC current to 120V of AC current by increasing the voltage of the power and then adjusting it so that it alternates. In simpler terms, it amplifies the 12V of DC current energy into 120V of AC energy.
This is not the only thing that an inverter does though. They also have bypass circuitry, especially on more advanced inverters. This means that when your motorhome is plugged in to shore power, the inverter will stop draining power from the batteries. This lets power from your generator flow through the circuits so that your batteries can recharge.
There are even some advanced inverters that have a special feature that allows you to use a “Hybrid” mode, also sometimes called “Power assist”.
These inverters are special. If the generator (or other source of shore power) does not have the capacity to meet the energy needs of your motorhome, it will allow you to use some of the energy from your battery. This lets you meet your energy needs without overwhelming the generator or draining your battery.
There are other types of power inverters, that take a different route. They control the loads on the circuits that they are powering so that you do not need as much power from the shore generator or your motorhome’s battery.
They monitor the load being pulled by the devices that they power. When that passes over a particular threshold, the inverter returns to “invert” mode. This takes these loads out of the draw on the generator or other source of shore power.
No matter what type of inverter that you have, using one allows you to use a lot more power in your motorhome than you would be able to if you were relying entirely on generator power.
How to Use Inverter in Motorhome?
There are a lot of different levels of inverter that you can get for your motorhome. Whatever type you have though, you probably won’t be able to use it to power all of the electric devices that you have onboard your motorhome. It will depend on how your manufacturer wired your motorhome to know how much you can power with your inverter.
It is also possible that you will have a motorhome that already comes with an inverter pre-installed when you get it from the factory. This pre-installed inverter is connected directly to the 12V battery bank, and it will have a control panel somewhere inside the motorhome that you can use to turn the inverter on or off.
The number of chargers and size of the electronics that you can power with these built in inverters depends on the size of the inverter. There are some built in inverters that still have small capacities and can only charge one or two relatively small devices such as a CPAP machine, laptop, TV, or DVD player.
It is rather rare, but there are still some motorhome inverters that can be wired to give power to your entire motorhome. Even with these inverters, you still need to be careful to not overload input power to the inverter by powering too many appliances with them all at the same time.
You should be especially careful about running too many large devices at once that need a lot of electricity. You also have to be careful about not draining too much of the motorhome’s battery by using it to power all of your gadgets at once.
Different Types of Motorhome Inverters
There are two main varieties of motorhome inverter. You can find pure sine wave and modified sine wave inverters. The primary difference between these two types has to do with their cost and their efficiency.
Pure sine wave inverters are more expensive but also more efficient than the modified sine wave inverters. Even though they are more expensive than modified sine wave inverters, their price has also been going down in recent years.
TIP – It’s always best to buy a pure sine wave inverter. Pure sine wave inverters provide the exact same kind of power that you get from the 240v AC power in your home. This is the type of power that all electric appliances and devices are intended to use.
Modified sine wave inverters are cheaper than pure sine wave inverters, but they are less efficient. They do not provide the exact same duplicate of 240v AC power that you can get from a pure sine wave inverter. This can sometimes cause problems and even failure with your electric devices.
Modified sine wave inverters are cheaper than pure sine wave inverters, but they are less reliable, and they can even cause damage to your appliances and electronic devices if you continue to use them over time.
Another problem with modified sine wave inverters is that they can create problems for your power supplies. You might notice that they are buzzing, heating up, or suffering from other problems.
You generally do not have to worry if you bought a motorhome, and it came with a modified sine wave inverter. However, you should keep in mind that there is a good chance that it will fail at some point.
When this happens, you should seriously consider upgrading to a pure sine wave inverter to get the best value for your dollar.
Will you be using mains power (Shore power)
If you will be using mains power connected to your campervan then you won’t need an inverter, with us we are off-grid a lot and rarely use mains hook up so an inverter is very much needed.
Does an inverter consume power when idle?
Yes, an inverter if on and nothing connected will still use power as it needs the power to run itself. We always turn ours off and on as we need it.
What Are the Best Motorhome Inverters?
There are a lot of options that you can choose from when you are looking for the right inverter for your motorhome. These are some of the best ones to consider, however.
Renogy 1000W 12V to 240V Pure Sine Wave Inverter
The inverter is a high-frequency power device that can be used to convert DC current from batteries or solar panels into AC voltage for household use. The leader in its field, this compact and portable unit efficiently powers TVs computers video game consoles Barbies VCRs – whatever you want powered up! With automatic safety monitoring circuitry included just make sure not hit “power” without first confirming there’s enough juice left over at your other outlets too
Xantrex
Xantrex Freedom XC 2000
Xantrex is one of the leading brands of 12v inverters for motorhomes. They have been around for years, and they have one of the best reputations of all the inverter companies in the motorhome industry.
These are quiet inverters that have a minimum draw on your battery resources. They handle continuing loads very well, but their surge ratings are lower than other brands. However, these are efficient inverters that will be reliable on all of your travels.
Xantrex inverters are more expensive than most motorhome inverter
AIMS
Aims Power Inverter
Aims Power is a relatively new company, but they already have a solid reputation for their motorhome inverters. They are also one of the most affordable high end pure sine wave inverters that you are going to find.
These inverters are extremely efficient, and they are known for having a strong surge protection. This is why they have gained such a reputation for their quality so quickly. If you are looking for a good budget friendly alternative to buying a Xantrex, AIMS is going to be one of your best options.
SAMLEX
Samlex Power Inverter
Samlex is another company that has been producing high quality motorhome inverters for a long time now. They have a great industry reputation, and you can never go wrong if you choose a motorhome inverter from them.
Samlex is definitely one of the more expensive companies that makes motorhome inverters, but you certainly get what you pay for with them. Samlex is virtually unmatched in terms of power, reliability, and durability.
Final Thoughts
If you plan to spend a lot of time travelling in your motorhome, you should consider getting a 12v inverter. This is a device that will transfer the DC power from your motorhome battery to the AC power that your electric appliances and devices need in order to run.
The size of the inverter that you need depends on the size of your vehicle battery or motorhome battery. It also depends on how many devices you plan to power and how much power each of those devices needs.
If you get an inverter that is too small, it will not give you enough juice to meet your needs. If you get one that is too big, it will be inefficient and be too much of an energy drain on your battery.
Keep up with our full-time van life travels over on our YouTube channel! If you enjoy our videos, please give us a thumbs up and subscribe to our channel 🙂 – Three As A Bird – Vanlife Travel – YouTube
You can take a look at some of our other van life posts which include lots and lots of hints and tips on all things van life here – Van Life – Travel Information, Hints, Tips and Advice (threeasabird.com)
If you’d like to follow more of our adventures or keep up to date with our travel hints and tips, please join our Facebook group, we’d love to connect with you all! –https://www.facebook.com/groups/309295536220437
Also, if you have Pinterest, please give us a follow for your van life travel inspiration! –https://pin.it/770Cq1Q
I have always wanted to travel and luckily I always got to travel to some amazing countries while I was growing up with my family and this really encouraged me to continue this and get out into the world on my own when I was older.
My goal growing up was really to see as much of the world as I could, but then I started going to work and really concentrating on my career and travel took a back seat. I still tried to get away a few times a year but I always knew there was an end goal which was to travel as much as possible.
So I got my head down and worked as hard as I could as an e-commerce manager. I have always been techy, I love computers and websites, so that’s where it gave me the idea to start this blog and also have my own web design agency. If you want to check it out or need any help then please take a look rrwebdesign.co.uk (shameless plug there)
But after covid, we both knew this was now the right time to take the leap and go and see the world after being trapped inside our house and working from home for a couple of years. We realised more than ever that you only get one life and you really need to make the most of it and do what you love!