A 500W power station can be exactly right for a weekend away and completely useless when the caravan kettle, coffee machine and induction cooktop are on the bench. The question is not simply what size power station is needed. It is what you need to run, for how long, and how you will put energy back into the battery.
Choosing the right size prevents two costly mistakes: buying a unit that cuts out when you need it most, or carrying far more battery capacity than your real use demands. For camping, caravanning, remote work, boats and blackout backup, the answer comes down to three figures - appliance watts, battery watt-hours and charging input.
Start with the appliances you actually use
Every appliance has a power draw, usually shown in watts (W) on its label, plug pack or manual. Watts tell you the instantaneous load the power station must handle while that appliance is operating.
A mobile charger may use 10-30W. A laptop commonly draws 45-100W. A portable fridge can average modest power across a day but uses more while its compressor is running. By contrast, a toaster, kettle, hair dryer, microwave and electric heater can demand 1,000W to well over 2,000W.
Add the watts of appliances likely to run at the same time. This is your minimum continuous output requirement. If you intend to run a 1,200W coffee machine while the fridge is cycling at 100W and a laptop charger is drawing 90W, look for at least 1,500W of continuous inverter output. Leave sensible headroom rather than operating at the limit every morning.
Some loads also have a start-up surge. Fridges, pumps and power tools can briefly draw more power when their motors start. A quality power station needs enough surge capacity as well as continuous output to deal with these short demands.
Do not confuse watts with battery capacity
A 2,000W power station is not automatically a large battery. The 2,000W figure may describe inverter output, meaning the largest appliance load it can supply. Battery storage is measured in watt-hours (Wh), which tells you how much energy it holds.
Think of watts as the size of the tap and watt-hours as the amount of water in the tank. You need a tap big enough to run the appliance, and a tank large enough to run it for the time you need.
Calculate how many watt-hours you need
Use a simple calculation for each appliance:
Watts x hours used per day = watt-hours per day
A 60W laptop used for five hours consumes around 300Wh. A 40W portable fridge averaging 12 hours of compressor run time over a hot day uses roughly 480Wh. A 1,000W kettle used for six minutes consumes about 100Wh.
Add your daily use, then allow for inverter losses, charging losses and real-world variation. A practical allowance of 15-20 per cent is sensible. Heat, cold, battery age and an unexpectedly cloudy day all affect the final result.
For a single overnight camp with phones, lights, a laptop and a small fridge, 500-1,000Wh can often be enough. For several days of caravan travel with a compressor fridge, fans, devices, water pump and occasional kitchen appliances, 1,500-3,000Wh is usually a more realistic starting point. Full-time off-grid use or household backup often calls for a larger, expandable system designed around daily energy use and charging opportunities.
The key is to avoid sizing a battery around one high-watt appliance. A kettle may need a powerful inverter but uses little energy if it only runs for a few minutes. A fridge has a lower running wattage yet can be the larger daily energy load because it runs day and night.
What size power station is needed for common uses?
There is no universal answer, but these real-world ranges provide a useful starting point.
Camping and short getaways
For lighting, phones, cameras, a laptop, a CPAP machine and a small portable fridge, choose a unit with enough inverter output for your largest device and around 500-1,000Wh of storage. If the fridge is staying on for more than one night, solar charging is worth considering from the outset.
This size suits people who want quiet power at camp without petrol, fumes or the constant background noise of a generator. It is also easier to lift, pack and move than a much larger system.
Caravans and touring rigs
Caravan use varies wildly. A couple running lights, fridge, water pump, Starlink, laptops and a TV has very different needs from a family using an air fryer, microwave and electric cooking appliances.
For dependable touring power, 1,500-3,000Wh with a 1,500-2,000W or larger inverter is commonly the practical middle ground. It can cover everyday 12V and USB loads while giving you the ability to use selected 240V appliances. But electric heating, air conditioning and full electric cooking can drain even a large portable battery quickly. Those loads need careful planning, substantial solar, charging while driving, or another power source.
Remote work and mobile trade use
A laptop, screens, satellite internet, mobile charging and LED work lights are manageable loads. Add power tools, compressors or battery chargers and inverter output becomes the priority.
Check the label on every tool charger and consider what runs together. A 1,000Wh battery may cover a workday of electronics but not repeated use of high-draw tools. For remote work where uptime matters, size for a full day of expected energy use plus a buffer, then build charging into your routine.
Blackout backup at home
A portable power station is ideal for keeping essentials operating during an outage: phones, modem, lights, laptops, medical equipment where appropriate, and a fridge managed carefully. It is not a like-for-like replacement for a whole-house grid connection.
Start with the appliances that protect comfort, communication and food. A 1,000-2,000Wh system can make a meaningful difference through a short blackout, especially when you avoid high-draw heating appliances. If refrigeration is critical, allow for its full daily consumption rather than only the power shown while the compressor is running.
Plan how you will recharge it
Battery capacity only tells half the story. A power station that lasts two days but takes four cloudy days to recharge may not suit extended off-grid travel.
Solar is the natural partner for quiet, fuel-free power. Estimate your daily consumption, then aim for enough panel capacity to replace it during average usable sunlight. Panel ratings are a best-case figure, so a 200W panel will not deliver 200W all day. Panel angle, shade, cloud, temperature and time of year all matter.
As a rough guide, 200W of solar can be useful for keeping light daily loads topped up, while 400W or more gives a better margin for fridges, devices and longer stays. The correct solar input depends on the power station's charging limit as well. There is little value carrying more panel capacity than the unit can accept.
Charging from the vehicle while driving is another useful layer, particularly for touring. For stationary off-grid living, a larger fixed solar array is generally more dependable than relying only on portable panels. When weather is poor or loads are heavy, a petrol smart inverter generator can still have a place as a backup charging option, rather than being your everyday source of power.
Allow for the conditions, not just the spreadsheet
Australian conditions can be unforgiving. Summer heat makes fridges work harder. A shaded camp site can sharply reduce solar harvest. On a boat, available space and corrosion resistance influence the setup. In winter, shorter days change what solar can realistically contribute.
It also pays to think about how you use power. Heating water with gas, cooking with gas or using a diesel heater instead of electric heating can dramatically reduce the battery size you need. This is often a more practical solution than buying a huge battery simply to support inefficient loads.
At Mobile Power Solutions, the systems we assemble are designed around this reality: people need usable, quiet power in the bush, on the road and when the grid fails, not impressive specifications that only work on paper.
Before choosing, write down each appliance, its wattage, how long it runs and whether it will operate alongside other loads. Then add a buffer and match the battery with a realistic solar and vehicle-charging plan. The right power station is the one that lets you get on with the trip, the job or the blackout without listening for a generator or watching the battery percentage every hour.