There are some electronics in your van life that simply can’t be powered directly from your 12V campervan batteries. These include things like laptops, blenders and microwaves. To power these devices you will need the help of an inverter.
Not everyone with a campervan will need an inverter, but for many it’s an essential piece of kit. Choosing the best power inverter for a camper can be a daunting task and there’s a few important considerations that need to be made before you make that decision.
In this guide I outline everything you need to know in order to make that inverter for camper purchase.
- 1 At A Glance
- 2 What Is An Inverter?
- 3 Types Of Inverters – Sine vs Modified Sine
- 4 What Size Inverter Do I Need?
- 5 Other Factors To Consider
- 6 The Best Campervan Inverters
- 7 Summary: Inverters For Campervans
At A Glance
Before I get stuck into the theory behind my choices, I’ll quickly outline the best inverters to consider for your van build or conversion.
What Is An Inverter?
An inverter is a device that converts DC current to AC current. DC current is the type of power coming from your van’s batteries and AC current is the type of power that comes from your wall sockets at home.
When choosing a camper power inverter you need to consider two main factors – how much power is required and what type of power is required.
Types Of Inverters – Sine vs Modified Sine
There are two types of power inverters – Pure Sine Wave (PSW) and Modified Sine Wave (MSW)
Without going into too much technical jargon, suffice to say that pure sine wave inverters produce a clean or smooth wave of AC current, similar to what you get from the grid.
Modified sine wave produce a stepped or blocked current that merely mimics the wave of AC current. In reality what this means is that some electronics may not work properly with modified sine inverters. It may cause the electronics to run less efficiently through more heat production.
PSW inverters are more expensive, so if you’re on a budget or aren’t planning to use complex or sensitive electronics, then opt for a MSW inverter. However, if you want to ensure your gadgets get pure, clean electricity then get a PSW inverter.
For the price difference I would always recommend choosing a PSW inverter.
Tip: Look for inverters that state Pure Sine or True Sine, otherwise they’re probably modified sine
What Size Inverter Do I Need?
This is the most important decision to make when choosing a camper van inverter and there are a few factors that influence it.
Inverters are sized by the amount of Watts of AC power that they can produce. They have ratings for peak/surge watts and continuous watts. Surge watts refer to the maximum amount of power that can be generated in one burst. This power will only last a short time, usually just a few seconds.
Continuous watts, as the name suggests, is the amount of power an inverter can continuously generate. This number is usually displayed in the inverter name.
1. Surge power demands
This is an important factor if you have any appliances that require an initial surge of power, such as a blender or a microwave. (Or as we discovered this Spring, washing machines – ahhh it’s a long story!).
Check the surge watt of your desired inverter can match the surge requirement of your appliances. If you’re not sure what your appliances’ surge demands are, just ask our old friend Google for the relevant appliance manual and take it from there.
2. Continuous power demands
To discover how much continuous energy you need, make a list of all the appliances that will require AC power and add up the wattage they use. This is a bit extreme since you likely won’t be using all of these appliances at the same time, but for arguments sake that’s the size inverter you require if you do.
Here are some typical appliance continuous power needs:
- Laptop 200w
- Blender 400w
- Dehumidifier 800w
- Hairdryer 1000w
Tip: Again, don’t forget that appliances like blenders and hairdryers will have higher surge demands, so make sure the inverter can handle the surge.
3. Inverter (In)Efficiency
Inverters are not 100 % efficient and will lose some energy when they convert power. Therefore you will need to add around 10-20% to your appliance total.
Note here that bigger is definitely not better due to the increased amount of inefficiency. A lot of power is lost through heat production and this increases with larger power inverters. Larger inverters also increase significantly in cost without seeing any real increase in benefit.
I’m all about low cost and big benefits when it comes to van life. (And life in general!)
But it’s not just what the highest surge requirement is or what the total continuous power will be, along with 10-20% for energy conversion loss. It get’s a little more complicated than that….
4. Battery capabilities
You also need to know if you have the capacity to power these appliances from your solar set up, namely your batteries. It’s important to buy an inverter that correctly matches the size and type of your battery. This is where many van lifers come unstuck.
Let me explain using the following example.
A 100ah battery can run a 1000w inverter at full power for 1 hour before it is completely drained. This is calculated through using the following equation:
Inverter watt load/volts = amps per hour
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.
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.
However, we don’t want our batteries completely drained. If you’ve read my guide to buying campervan leisure batteries, you will know that it’s harmful for batteries to let go of all of their energy at once. We know lead acid batteries should only be discharged to 50% of the maximum before being recharged. (For lithium batteries the depth of discharge is more like 80% and for some AGM batteries it’s more like 70%).
So in this instance, the inverter should only be run for 30 minutes, after which you will start depleting your battery’s lifespan.
With these four considerations in mind, you can now work out what your power needs are. Can your electrical system support your power needs? If not, something has to give and it could be as simple as never using all of your appliances at once!
Other Factors To Consider
Will you be using hook-ups? (shore power)
Consider an inverter which has a transfer switch which will power devices from mains hook-up when you’re plugged in and flip to the inverter when you’re running off-grid.
Or you could consider an inverter/charger. These operate as a battery charger when your van is plugged into the mains and a regular inverter when you’re running off the batteries. This is quite handy if you need to supplement your solar setup, for example during winter when daylight hours are limited (at least here in the UK!)
Do you really need an inverter?
If you only use your van on weekends or small trips do you actually have any appliances which require AC current? Most gadgets come with USB chargers these days which makes inverters somewhat redundant.
Power inverters actually uses a little power, even when they’re not running so this needs to be factored in.
Safety certification standards
It’s worth considering whether the inverter conforms to recognised safety standards to ensure to it’s completely safe to use. For example ETL or CE.
As with many things electrical, it’s also worth noting if the inverter is manufactured by a reputable brand or just some random company that’s popped up on Amazon and doesn’t have any reviews yet. Cheap prices can also be a giveaway here.
The Best Campervan Inverters
1. Best Overall – Renogy 1000W Pure Sine Inverter 12V to 240V
This pure sine inverter from Renogy is the best value, highest quality product on the market. Renogy are a reputable brand who make top quality batteries, solar panels and charge controllers amongst things. You know you’re gonna get a good product and top service when you buy from Renogy.
This inverter offers 1000w continuous power and 2000w surge power, although higher power options are also available. It has a high conversion efficiency of 90%, is ETL listed and is similarly priced to no-named alternatives. What’s not to love?
2. Best budget choice – Giandel 1000W Pure Sine Inverter 12V to 240V –
This pure sine inverter from Giandel has the same spec as the Renogy inverter but is slightly cheaper. It offers the same protection from overload and high temperature, however the biggest downside is that it only has one socket. If you upgrade to the 2000w version you then have two sockets, but that’s a £100 difference, which is quite a big jump in price.
Giandel do offer a 12 month warranty, but for the mere £30 price difference between the two, I would personally opt for the Renog and take peace of mind that I have a top quality product.
Summary: Inverters For Campervans
Inverters are devices which convert DC power to AC power. This allows campervaners to use electronics which require power in the form of AC current from their DC batteries. These devices include laptops and blenders.
When deciding which inverter to buy there are several factors to consider, including whether to use pure sine wave or modified sine wave and how much power the inverter needs to convert. Power demands will need to measured against the capabilities of your batteries.
Most van lifers will be able to comfortably run a 1000w inverter to cover their power needs. If you have a lot of power thirsty appliances and have the battery capacity to support it, opt for a 2000w inverter.