LINEX

Portable Power Station Sizing: What Size Do You Need

Short answer: Add up the watts and run time of each device to get watt-hours, divide by about 0.85 for inverter losses, then choose a station with at least 1.3× that capacity and an output rating above the largest single load. A phone and lights need 100Wh; a fan and TV need 500Wh; a fridge needs 1,000Wh or more.

The label on a power station mixes two numbers that people confuse: output watts (how much it can run at once) and capacity watt-hours (how long it can run). Sizing means checking both.

Typical Loads

Device	Power	Energy for 4 hours
Phone charger	10W	40Wh
LED light	10–15W	50Wh
Fan	30–50W	160Wh
Laptop	60W	240Wh
TV	60–100W	320Wh
Small fridge	80–150W (cycling)	600–900Wh

The Formula

Watt-hours needed = watts × hours ÷ 0.85. A 60W TV for four hours needs about 282Wh. Add devices that run at the same time, then add 30% margin for cold, aging and inverter inefficiency.

Choose the Class

Class	Typical capacity	Good for
100W	About 77Wh	Phones, lights, small DC devices, emergency
300W	About 300Wh	Camping, fan, TV, laptop, small appliances
1000W	About 1,000Wh	Fridge, tools, longer backup

Output Rating vs Capacity

A 300Wh station with a 300W inverter cannot run a 600W kettle, no matter how much energy it stores. Check the continuous output and the surge rating for motor loads, then check capacity for run time.

Charging Time

Solar input is usually the bottleneck: a 100W panel delivers roughly 60–80W in real conditions, so a 300Wh station needs 4–6 hours of good sun. Wall charging is faster; confirm the input wattage before planning a solar-only setup.

Frequently asked questions

Can a 300W power station run a fridge?

A small fridge with a 100W running load can work, but the compressor surge may exceed the station’s peak rating. Check the surge figure and expect 6–9 hours from a 300Wh unit at 50% duty.

How long will a 100W station run a fan?

A 30W fan draws about 30Wh per hour; a 77Wh station gives roughly two hours after inverter losses.

Is a bigger station always better?

No. Bigger units weigh more and cost more; if you only charge phones and lights, a 100W class unit is enough and far easier to carry.

What does 76.8Wh mean?

It is the stored energy — about enough to charge a phone six to eight times or run a 10W light for seven hours. It is not the output wattage.

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