Backup Power Sizerby SurvivalTrends

What size power station do you need?

For the essentials, about 630 Wh gets you through an evening and about 2,520 Wh through a full day. Pick what you want to keep running and the calculator sizes it for you, with matched models from EcoFlow, Jackery, Bluetti, Anker SOLIX and ALLPOWERS.

What size power station do I need?
Step 1 of 3: what do you want to keep running?

A typical evening outage

Fridge, Wi-Fi, LED lights and two phones for 6 hours

  • Fridge360 Wh
  • Phones30 Wh
  • Wi-Fi router72 Wh
  • LED lights72 Wh
  • Losses and rounding96 Wh
630 Whbattery needed, rounded up
  • Free, with the answer straight away. No email needed.
  • Every result shows its maths.
  • Specs from each manufacturer’s own pages, checked 16 October 2026.
  • Picks come from the numbers, not from which brand pays more.

More free tools

What do common outage plans need?

Each row is the calculator run on a typical plan. Open any row to change it to your own list.

PlanBatteryStart-up peakCalculator’s pick
Evening outage: fridge, Wi-Fi, lights, phones630 Wh972 WAnker SOLIX C800 PlusOpen this plan
Full day: fridge, Wi-Fi, lights, phones2,520 Wh972 WEcoFlow DELTA ProOpen this plan
Work from home for a day: laptop, Wi-Fi, lights, phones1,390 Wh137 WJackery HomePower 2000 Plus v2Open this plan
CPAP (no heater) and phones for 6 hours320 Wh80 WAnker SOLIX C800 PlusOpen this plan
Fridge and chest freezer for a full day2,970 Wh1,000 WEcoFlow DELTA ProOpen this plan
Fridge only for three days, with a solar panel2,620 Wh900 WEcoFlow DELTA ProOpen this plan
Gas furnace fan for an evening1,770 Wh900 WJackery HomePower 2000 Plus v2Open this plan
Sump pump for a full day4,240 Wh1,500 WA generator is the better fitOpen this plan
Three days of essentials, with a solar panel5,070 Wh972 WA generator is the better fitOpen this plan

How do the 15 power stations compare?

Sorted by battery size. “Fridge alone” is how long each runs a typical fridge with nothing else plugged in. The pick column shows which of the plans above each model wins in the calculator.

ModelBatteryOutputFridge aloneWeightWarrantyCalculator’s pick forNot for you if
EcoFlow River 3 PlusPre-order on 14 Oct286 Wh600 W
1,200 W surge
4.1 h10 lbnot statednone of these plansYou have a sump pump: it can’t start a typical one
You want to use a microwave: under 1,100 W output
You want the warranty in writing: not stated on the maker’s page
Jackery Explorer 300 v2Sold out on 14 Oct288 Wh300 W
600 W surge
can’t start8 lb5 yrnone of these plansYou need to run a fridge: it can’t start one
You have a sump pump: it can’t start a typical one
You want to use a microwave: under 1,100 W output
Jackery Explorer 600 v2Sold out on 14 Oct640 Wh500 W
1,000 W surge
9.1 h14 lb5 yrnone of these plansYou have a sump pump: it can’t start a typical one
You want to use a microwave: under 1,100 W output
EcoFlow River 2 ProPre-order on 14 Oct768 Wh800 W
1,600 W surge
11 h18 lb5 yrnone of these plansYou want to use a microwave: under 1,100 W output
Anker SOLIX C800 Plus768 Wh1,200 W
1,600 W surge
11 h24 lb5 yrEvening outage essentialsCPAP for a night–
EcoFlow DELTA 3 Classic1,024 Wh1,800 W
surge not stated
15 h27 lb5 yrnone of these plansYou need a published surge rating: the maker doesn’t state one
Anker SOLIX C10001,056 Wh1,800 W
2,400 W surge
15 h28 lb5 yrnone of these plans–
Jackery Explorer 1000 v2Availability unclear on 14 Oct1,070 Wh1,500 W
3,000 W surge
15 h24 lbnot statednone of these plansYou want the warranty in writing: not stated on the maker’s page
Bluetti AC1801,152 Wh1,800 W
2,700 W surge
16 h35 lb5 yrnone of these plans–
ALLPOWERS R15001,152 Wh1,800 W
3,000 W surge
16 h37 lb5 yrnone of these plans–
EcoFlow DELTA 2 MaxPre-order on 14 Oct2,048 Wh2,400 W
4,800 W surge
29 h50 lb5 yrnone of these plansYou need to carry it: 50 lb
Jackery HomePower 2000 Plus v22,048 Wh2,400 W
4,800 W surge
29 h41 lb5 yrWorking from home for a dayFurnace fan for an evening–
EcoFlow DELTA Pro3,600 Wh3,600 W
7,200 W surge
2.1 days99 lbnot statedA full day of essentialsFridge and freezer for a dayFridge for 3 days with solarYou need to carry it: 99 lb
You want the warranty in writing: not stated on the maker’s page
Anker SOLIX F38003,840 Wh6,000 W
9,000 W surge
2.3 days132 lb5 yrnone of these plansYou need to carry it: 132 lb
EcoFlow DELTA Pro 34,096 Wh4,000 W
8,000 W surge
2.4 daysnot stated5 yrnone of these plans–

Specs from each manufacturer’s product page, checked 16 October 2026. Stock notes are from the same date and change often. See the full runtime chart for every appliance.

How does the calculator work?

  1. What you keep on

    Each item has a typical average draw. A fridge is rated around 150 W, but its compressor switches on and off, so over a day it averages about 60 W.

  2. For how long

    Average draw × hours gives the energy you need. We add inverter losses (18%) and round up to a real battery size.

  3. Can it start it?

    Fridges, pumps and furnace fans spike when they start. The station’s output and surge ratings must cover that, so we check both.

How long will a power station run…?

Questions people ask before buying

What size power station do I need for a power outage?

For the essentials (fridge, Wi-Fi, LED lights and two phones) you need about 630 Wh to get through an evening and about 2,520 Wh for a full day. Add anything bigger, such as a freezer, CPAP or furnace fan, and the number rises; the calculator above adds it up for your list.

How long will a 1,000 Wh power station run a fridge?

About 14 hours. A typical fridge averages around 60 W because its compressor cycles, and a 1,000 Wh battery delivers about 850 Wh after inverter losses.

What size power station do I need for a fridge?

For one evening (6 hours) a fridge needs about 424 Wh of battery; for a full day about 1,694 Wh. The station also needs enough surge output for the compressor to start, usually around 900 W.

What is the difference between Wh and W?

Watt-hours (Wh) is how much energy the battery holds: how long it lasts. Watts (W) is how much power it can deliver at once: what it can run. You need enough of both.

Why does the calculator add about 15% to my total?

Because turning battery power into household AC power loses energy in the inverter. We assume 85% efficiency, which is typical, so a 1,000 Wh battery delivers about 850 Wh to your devices.

Can a power station run a sump pump?

Yes, if it can supply the start-up spike: a typical sump pump runs at about 800 W and needs about 1,500 W for a moment when it starts. How long it lasts depends on how often the pump cycles; at an average of 150 W, a 1,000 Wh station gives about 5.7 hours.

Can a power station run a space heater?

Only briefly. A space heater draws about 1,500 W on high and averages around 750 W as the thermostat cycles, so a 1,000 Wh station lasts about 1.1 hours. For heat through a long outage, a generator or a gas furnace with its fan on battery is the realistic route.

Can a power station run a CPAP all night?

Usually yes. Most CPAPs draw 30–60 W without the heated humidifier, so a 300 Wh station covers one night with some margin. The humidifier can double or triple the draw. Check your machine's label and keep a margin for any medical device.

Is a power station or a generator better for a power outage?

A power station is better for essentials; a generator is better for big loads. A power station is silent, needs no fuel and is safe to use indoors, so it suits fridges, phones, Wi-Fi, lights and CPAPs. For whole-house loads, electric heating or outages of several days, a generator is usually cheaper. Never run a fuel generator indoors or in a garage.

Can I use a power station indoors?

Yes. A battery power station gives off no fumes, so it is safe to use inside, unlike a fuel generator. Keep it on a dry, flat surface with its vents clear.

Why are all the models on this page LiFePO4?

Because current power stations from these five brands use LiFePO4 (lithium iron phosphate) batteries. They last many more charge cycles than older lithium-ion packs and are more stable, which matters for something that sits ready for years between outages.

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