Why Buying a Portable Power Station for Your Motorhome Is Almost Always a Mistake
This is an AI generated article to my bullet points. I have checked it carefully and am reasonably happy with it - it makes the basic points, and has saved me about half a day - what it usually takes to write a long blog post.
There are some Classic Hymer specific notes at the end.
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Walk into any outdoor store today and you will be greeted by a wall of glossy, suitcase-shaped “portable power stations” (PPS). Jackery, EcoFlow, Bluetti, Allpowers, and a dozen others promise silent, limitless off-grid freedom at the push of a button. They look sleek, they feel high-tech, and the marketing departments deserve a medal.
But for motorhome owners, they are a poor buy.
Not because they do nothing useful—quite the opposite. A PPS is undeniably handy in a tent or a shed. The issue is that a motorhome already contains every component a PPS is built from. Purchasing one is rather like buying a second kettle to boil water you already have hot on the hob.
Let us unpack why.
A Portable Power Station Is Just a Battery in a Pretty Box
A PPS is essentially:
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A battery
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A small inverter
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A small mains charger
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A screen and a handle
That is it. The clever part is not the technology but the packaging.
Motorhomes already come equipped with:
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A leisure battery
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A mains charger
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A 12 V distribution system
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Often an inverter (and if not, one can be added for far less money)
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Solar – these days nearly all motorhomes have roof-mounted solar fitted as standard or added later
So when you buy a PPS for £400–£2,000, you are buying a second set of equipment you already own—except smaller, and usually harder to integrate with the rest of your system.
If your goal is more off-grid power, the answer is to upgrade the motorhome’s leisure battery and charging setup, not to add an entirely separate battery system in a suitcase that sits on the floor.
Understanding the Numbers: Watts vs Watt-hours
This is where many people are misled.
Motorhomes traditionally come with a 100 Ah leisure battery at 12 V. Very roughly:
100 Ah × 12 V ≈ 1,200 Wh of energy
Only about two-thirds is typically usable, so call it 800 Wh of practical energy.
A PPS often advertises something like “1,000 W output.” Note the trick:
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W (watts) = power (the “speed” of energy use)
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Wh (watt-hours) = energy stored (the “size of the tank”)
A 1,000 W PPS can output 1,000 W, but that tells you nothing about the size of its battery. Many 1 kW PPS units contain only 800–1,000 Wh of energy.
In other words: a PPS that “sounds huge” in the advert is often barely bigger than the 100 Ah battery you already have.
Marketing departments rely on people confusing the two units.
The Real Off-Grid Constraint: Your Consumption
People are used to unlimited grid electricity. You plug in an appliance, it works, and you never consider what it is doing behind the scenes.
Off-grid, every appliance becomes a calculation.
The rule is brutally simple:
Anything that generates heat uses a lot of power.
Examples:
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Coffee machine: 800–1,500 W
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Air fryer: 1,200–1,800 W
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Kettle: 2,000–3,000 W
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Hair dryer: 1,200–2,400 W
Now compare these with your available supply:
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Typical PPS: 500–1,200 Wh
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Typical motorhome leisure battery: ~800 Wh usable
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Upgraded lithium battery: 1,500–3,000 Wh
Suddenly, “1,000 W” does not seem so mighty.
Run a 1,000 W appliance for 30 minutes and you can easily empty a PPS completely. Then you face an equally unpleasant challenge: where are you going to get the energy to refill it?
The Three Ways to Charge Anything in a Motorhome
A motorhome has only three charging sources:
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Solar
Excellent in summer, negligible in winter. Limited by roof space. -
Electric Hook-Up (EHU)
Perfect when available. Never available when you actually need it. -
Alternator (driving)
Strong source, but only works when the engine is running.
A PPS adds a fourth battery you must now keep charged, using the same limited sources. And most PPS units charge quite slowly unless plugged into a large mains supply.
It is the opposite of convenient.
Why a Proper Motorhome Upgrade Is Better and Cheaper
If you want meaningful off-grid capability, do this instead:
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Upgrade your leisure battery
Swap your old 100 Ah AGM/gel for a 100–200 Ah lithium battery.
Price: ~£250–£800
Usable energy: dramatically higher. -
Ensure your charger(s) can handle lithium
Many vans only need a small update. -
Add or expand solar
100–300 W of roof solar is transformative. -
Add an inverter (if you need 230 V)
A good-quality 1,000–2,000 W inverter costs a fraction of a PPS’s markup.
The result:
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Larger battery capacity
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Faster and more flexible recharging
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Seamless integration with the van
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No extra box to drag around
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No duplicated chargers and inverters
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Lower cost per watt-hour
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A system designed for motorhome use, not for camping marketing brochures
A PPS, by contrast, is a small sealed battery you cannot upgrade and which duplicates systems you already own.
The Bottom Line
In a tent, a portable power station is a brilliant piece of kit.
In a motorhome, it is an expensive toy.
If your goal is off-grid capability, invest directly in the motorhome’s electrical system. Your money goes far further, your power capacity increases meaningfully, and everything charges and operates as a single coherent system—not as a collection of mismatched boxes.
The glossy suitcase with the handle may look tempting, but for motorhome owners it is nearly always the wrong tool for the job.
Ron again ... some notes and comments for Hymer owners.
PPSs can be useful for owners who don't use their vans a lot, or have other uses for a PPS - eg camping.
I do accept that they can be very convenient in some cases as long as the purchase is well thought out and researched properly.
The situation to be avoided is (and I have seen this many times) is a PPS on the ground outside a van, plugged in to the vans EHU.
However the point made in the article about misleading advertising is valid. Use of terms like "available power" and "upgradeable" .... I am tech savvy and sometimes I have to scroll for ages and dig deep to get the real numbers.
In 2025, rough costs are as follows. 300ah (3,600wh) lithium battery, around £400. make sure you buy a smart bluetooth battery so you have info at your fingertips at all times.
A decent inverter - ie Renogy or Victron - around £200.
Solar has never been cheaper .... and don't forget that a meaningful upgrade to your van electrics opens up all sorts of other possibilities - eg coffee machines - airfryers - slow cookers. And if you don't want any of these "luxuries" then it simpy translates into more days off grid, less days on campsites at £30 a night.
When planning an upgrade, work back from what you want to do, and specify to achieve it.
The worst thing to do is buy it just to play with it.
