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A high capacity power station is a large portable battery with a built-in inverter, made to run household loads through an outage or away from an outlet. Capacity is the size of the battery, output is how much power it can deliver at once, and recharge is how you refill it, by wall outlet, car outlet or solar panels. The steps below show how to work out the capacity you need, check the output and outlets, and plan the recharge before you buy.
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The quick answer
Add up the energy your loads use over the hours you need to cover, then pick a station with at least that much capacity. Allow for losses, because the inverter that turns battery power into household AC loses some energy as heat, and most stations stop before the battery is fully empty. Then check that the continuous AC output covers the running watts of everything you plug in at the same time, and that the surge power can start motors and compressors. The steps below show how to work it out from your own loads.
Find how much power your loads need
The most reliable figure is the label on each load, which lists watts, or the spec sheet, which lists energy use. A plug-in watt meter between the load and the outlet measures real use over a day, which is the best figure if you can get it. List every load you plan to run, from the fridge and lights to the phone charger and laptop, and add their energy use together.
| Load | What to check | Notes |
|---|---|---|
| Fridge or freezer | Running watts and startup draw | Compressor cycles on and off, so use daily energy, not the label watts alone |
| Lights and phone chargers | Small steady draw | Adds up over long evenings |
| Laptop and router | Charger watts and hours of use | Keep them on the station only while you need them |
| TV | Running watts and hours of use | Screen size and brightness move the draw |
These are planning notes only. How long each load runs and how often it cycles all move the figure, so use your own label or meter reading.
Turn that into battery capacity
Work out the hours you want to cover. For a full day, use the daily figure. For an overnight outage, take the hours you need out of the day. Then allow for inverter and battery losses, because the inverter loses some energy as heat and most stations stop before the battery is fully empty. If you also want to run lights, a phone charger or a CPAP from the same unit, add their energy use before you size the station. See the best portable power stations for home backup for larger units.
Check output and outlets
Capacity sets how long the loads run. Output sets whether they run at all.
- Continuous AC output: must exceed the running watts of everything you plug in at the same time.
- Surge power: a motor or compressor pulls a short spike when it starts. If the surge power is too low, the station shuts off each time the motor kicks in.
- Pure sine wave: loads with motors and electronic controls should run on pure sine wave AC, which almost all current stations provide. See the best inverters for a refrigerator if you plan to run a fridge from a battery bank instead.
- Outlets: count the AC outlets, USB ports and car outlets against the loads you plan to plug in, and check that the station has the outlet types your loads need.
Plan the solar recharge
For an outage that lasts more than a day, the panels have to put back what the loads used. Panel watts times peak sun hours, less real-world losses, gives the daily recharge. Check the station’s maximum solar input in watts and volts before you buy panels, and match the panel voltage to the input the station lists. See the best portable solar panels for options.
How to choose the best high capacity power station
Compare capacity, output, outlets and recharge across the stations you shortlist, and pick the station that covers your loads for the hours you need. A station that is too small for the fridge will shut off when the compressor starts, while a station far larger than your loads adds weight and bulk you do not need.
Check the recharge options too: a station that takes solar input can refill during a long outage, while a station that only charges from a wall outlet needs the grid back before it can recharge. Match the solar input to the panels you own or plan to buy.
Ways to make the battery last longer
- Keep the fridge door shut and the fridge full; a full fridge holds its cold.
- Turn off the ice maker and any door heater or energy-saver switch that adds load.
- Pre-chill before an expected outage and move items you need often to a cooler.
- For camping and vans, a compressor fridge running on DC avoids inverter loss entirely. See the best 12V refrigerators for RVs.
FAQ: power away from the grid
What is a high capacity power station?
A high capacity power station is a large portable battery with a built-in inverter that runs household loads away from an outlet or through an outage. It stores energy in its battery and runs AC loads through the inverter, and it can recharge from a wall outlet, a car outlet or solar panels.
How to size a power station for home backup
Add up the energy your loads use over the hours you need to cover, allow for inverter losses, and pick a station with at least that much capacity. Then check that its continuous AC output covers the running watts of everything you plug in at the same time.
Can a power station run a fridge and a freezer together?
Add the energy use and running watts of each, and plan for the compressors starting at the same moment, which raises the surge draw. A larger unit or an expansion battery is often needed. See the best solar generators for a freezer.
Is a solar generator the same as a portable power station?
Mostly. A solar generator is a portable power station sold with, or able to take, solar panels as its charging source. Each stores energy in a battery and runs AC loads through a built-in inverter.
Related solar guides
See the best portable power stations for home backup, the best solar generators for a freezer, the best deep cycle batteries for a refrigerator and the best watt meters.
