A flat battery at sunset, a fridge full of food during a blackout, or a caravan parked well away from a powered site will quickly answer the question: “what size power station do I need?” The right answer is not the biggest unit you can fit in the back of the ute. It is the system that can run your gear safely, for long enough, and recharge fast enough to keep up with how you actually live.
For most people, choosing a power station comes down to three figures: battery capacity in watt-hours (Wh), inverter output in watts (W), and solar input. Get one of those badly wrong and even an expensive power station can become a frustrating limitation.
What Size Power Station Do I Need?
Start with the appliances you genuinely expect to use, not every electrical item you own. A weekend camper charging mobiles and running LED lights has very different needs to a full-time traveller powering a compressor fridge, CPAP machine, laptop and coffee maker.
Battery capacity tells you how much stored energy you have. Inverter output tells you what the power station can run at any one time. Solar charging determines whether you can replace the energy you use without needing mains power or a generator.
A useful way to think about it is this: watts are the speed at which an appliance uses energy, while watt-hours are the amount of energy consumed over time.
The basic calculation is:
Appliance watts × hours used per day = watt-hours needed per day
A 60W portable fridge that averages 10 hours of compressor run time over a hot day may use around 600Wh. A 10W LED light used for five hours uses only 50Wh. A 1,200W kettle might only run for three minutes, but still uses about 60Wh each time it boils.
Add each item together, then allow a practical buffer of at least 20 to 30 per cent. Batteries, inverters and appliances are not perfectly efficient, and real conditions are rarely as neat as a spreadsheet. Hot weather makes fridges work harder. Cloudy days reduce solar harvest. Someone will always charge an extra device.
Battery Capacity: How Much Runtime Do You Need?
For short trips, a smaller lithium power station can be enough when your loads are modest and you can recharge from the vehicle or solar panel. For longer stays off-grid, battery capacity becomes the difference between relaxed independence and constantly watching the display.
Light camping and day use: 300Wh to 700Wh
This range suits charging mobiles, cameras, drones, a laptop, LED lighting, a small fan and perhaps a low-draw fridge for limited periods. It is a sensible choice for overnight camping, day trips, events, or as a compact emergency unit at home.
It is not the right fit for sustained fridge use in hot weather, high-power cooking appliances, or several days without reliable charging. A compact unit is easy to carry, but capacity disappears quickly once refrigeration enters the picture.
Weekend camping and simple caravan use: 1,000Wh to 2,000Wh
For many Australian campers and caravan owners, this is the practical middle ground. A power station in this range can support a compressor fridge, lights, mobiles, laptops, television, a CPAP machine and water pump use, particularly when paired with suitable solar.
A 1,500Wh battery does not mean you can use 1,500Wh every day forever. It means you have a useful reserve to get through overnight and cover poor solar conditions. If your daily use is around 700Wh to 1,000Wh, a solar array capable of putting that energy back during the day makes the system far more capable.
Serious off-grid travel and backup power: 2,000Wh to 5,000Wh+
This is where power stations start supporting a more independent setup: multiple fridges, regular laptop work, Starlink, larger water pumps, television, power tools, kitchen appliances used in moderation and longer periods away from mains power.
For rural homes and blackout preparation, a larger system can keep essential circuits and appliances operating without the noise, fumes and fuel storage that come with a petrol generator. The exact capacity still depends on your loads. Running a fridge, lights, internet and charging is realistic. Running ducted air conditioning, electric hot water and an entire household is a different job and calls for a properly designed off-grid system.
Do Not Forget Inverter Size
A large battery paired with a small inverter can still leave you unable to run the appliance you need. The inverter converts battery power into 240V AC power, and its continuous watt rating must exceed the combined appliances you want to operate at once.
If you want to run a 1,000W microwave while a fridge is cycling and a 100W laptop charger is connected, a 1,200W inverter is too close to the edge. Choose enough continuous output for the likely load, with sensible headroom.
Motor-driven appliances need special attention. Fridges, pumps and some tools draw a short startup surge that can be several times their running wattage. A fridge may only use 60W while operating but demand much more for a moment when the compressor starts. A quality power station should have a capable surge rating, but checking the appliance label and specifications before buying avoids surprises.
High-draw heat appliances are the quickest way to drain any battery. Kettles, air fryers, induction cooktops, electric heaters, toasters and hair dryers can be used from a suitable high-output station, but they consume energy rapidly. A 2,000W appliance running for 30 minutes uses roughly 1,000Wh. That is a major share of a small or mid-sized battery.
Size Your Solar to Your Daily Use
Solar is what turns a portable battery into a genuinely useful off-grid power system. Without it, your runtime is limited to what was stored before you left home. With the right solar input, you can run daily loads and restore the battery while the sun is available.
As a rough starting point, a 200W solar panel may deliver around 700Wh to 1,000Wh on a good sunny day, depending on panel angle, season, temperature, shading and location. In winter, poor weather, or when panels are laid flat on the ground, output can be much lower.
If you expect to use 1,200Wh each day, do not assume a single 200W panel will comfortably cover it. A larger solar array gives you margin for the days that matter most. It also lets you recharge earlier, rather than spending the entire day chasing sunlight.
Check the power station's maximum solar input and voltage range before adding panels. More panel wattage is only useful if the station can accept it. Portable panels are flexible and convenient for travel, while fixed roof-mounted panels are often better for caravans and canopies. Many experienced travellers use both: roof solar for daily background charging and a portable panel to catch better sun when camped under trees.
Real-World Examples
A simple camper setup with a 40L compressor fridge, lights, mobiles and a small speaker may consume 500Wh to 800Wh per day. A 1,000Wh to 1,500Wh power station with 200W to 300W of solar is usually a comfortable starting point, especially for weekend trips.
A caravan setup with a larger fridge, water pump, television, laptop, Starlink and regular charging could use 1,200Wh to 2,000Wh daily. A 2,000Wh or larger station, paired with 400W or more of solar where supported, provides far more breathing room.
For remote work or extended off-grid living, calculate every load rather than guessing. A laptop may be modest, but internet equipment running all day, refrigeration, lighting, pumps and cooking add up. In this situation, battery capacity should cover at least a full day of typical use, preferably more, while solar is sized to recover average daily consumption.
For home backup, decide what “essential” means before buying. Keeping a fridge, freezer, NBN equipment, lights, a few device chargers and selected medical equipment running is achievable with a properly sized lithium power station. Electric ovens, reverse-cycle air conditioners and large heaters should generally be excluded unless the system has been specifically designed for them.
Choose for the Conditions, Not the Sales Sticker
The smallest unit that technically runs an appliance is rarely the best unit to own. A power station that is constantly near empty, overloaded, or waiting on marginal solar takes the freedom out of being off-grid.
At Mobile Power Solutions, the focus is on practical energy independence: quiet lithium power that works in a campsite, caravan, boat, shed or during a blackout. Australian-assembled ESCAPE power stations are built around the reality that people need dependable power, not optimistic claims.
Before choosing, write down each appliance, its wattage and expected daily runtime. Then check the highest loads you may run together, add a realistic battery buffer, and plan enough solar to replace what you use. When the grid fails or the nearest powered site is kilometres away, that extra planning means you will not be left in the dark.
Browse our full off-grid system range to find the right size for your setup.