Power stations › Scenarios › Space heater on battery

How long will a power station run a space heater?

Q: How long will a power station run a space heater?

Plan on a power station with at least 3950 watt-hours of capacity and 1500W continuous / 1500W surge output to run this for 2 hours. A Expandable home backup (≈6,000Wh+) covers it, running the load about ~3.1 h on a charge.

This is the scenario that surprises people: a 1,500W space heater is the worst possible load for a power station. Resistive heat converts watts straight to heat with no efficiency to exploit, so even a large station empties in a couple of hours. The honest answer is usually 'not for long.'

The load

Space heater (1500W) — 1500W running

POWER PLATE1 LOAD · 2 H RUNTIME

Continuous draw

1,500 W

Startup surge

1,500 W

Energy for 2 h

3,529 Wh

Buy at least

3,950 Wh

Look for ≥3,950Wh capacity, ~1,500W continuous / 1,500W surge or better.

Field note: For warmth on battery power, a heated blanket or a 12V seat-style heater draws a tenth of what a space heater does and will run all night on a small station. If you truly need 1,500W of resistive heat for hours, a fuel-burning generator is the right tool — this is a case where a power station is the wrong fit.

Right size: Expandable home backup (≈6,000Wh+) · 5,000W

Typical price $3,500-6,000+ · e.g. EcoFlow Delta Pro Ultra, Bluetti AC500 + B300S (stackable)

Backing up whole circuits through a transfer switch; add battery modules for days of autonomy, especially with solar. A home-backup system, not a grab-and-go unit. For 240V loads or true whole-home coverage, compare against a standby generator.

Runs this load ~3.1 h on a full charge.

See current prices on Amazon

Adjust for your setup

Different loads or runtime? Uncheck and re-check below and drag the runtime slider — the plate recomputes live.

POWER PLATE1 LOAD · 2 H RUNTIME

Continuous draw

1,500 W

Startup surge

1,500 W

Energy for 2 h

3,529 Wh

Buy at least

3,950 Wh

Look for ≥3,950Wh capacity, ~1,500W continuous / 1,500W surge or better.

Capacity includes inverter loss (~15%) and a usable-charge margin, so the station isn't run flat. A solar panel or vehicle charge extends runtime past this number.

How long do you need to run it? 2 h

Kitchen Refrigerator (full-size) 300W run / 1500W start Mini fridge 90W run / 700W start Chest freezer 250W run / 1200W start Microwave (1000W) 1400W run Electric range (one burner) 1500W run Coffee maker (drip) 900W run Toaster 1100W run Electric kettle 1400W run Dishwasher 1300W run / 1500W start Instant Pot / multicooker 1000W run

Heating & cooling Window AC (5,000 BTU) 500W run / 1500W start Window AC (8,000 BTU) 800W run / 2200W start Window AC (12,000 BTU) 1100W run / 3000W start Central AC (3-ton) 3500W run / 8500W start Space heater (1500W) 1500W run Furnace blower fan (gas furnace) 600W run / 1600W start Heat pump (2-ton) 2500W run / 6000W start Box fan 100W run / 150W start Ceiling fan 75W run / 100W start

Pumps & well Sump pump (1/3 HP) 800W run / 1500W start Sump pump (1/2 HP) 1050W run / 2200W start Well pump (1/2 HP) 1000W run / 2100W start Well pump (1 HP) 2000W run / 4000W start Sewage ejector pump (1/2 HP) 1000W run / 2200W start

Electronics TV (55" LED) 80W run Wi-Fi router + modem 15W run Laptop 65W run Desktop PC + monitor 350W run / 400W start Phone charger 10W run Starlink dish + router 75W run / 100W start

Medical & safety CPAP machine 60W run Oxygen concentrator 350W run / 600W start

Lighting LED lights (per room) 30W run

Laundry Washing machine 700W run / 1600W start Clothes dryer (electric) 5000W run / 6000W start Clothes dryer (gas) 700W run / 1800W start

Household Garage door opener (1/2 HP) 550W run / 1200W start Water heater (electric tank) 4500W run EV charging (Level 1, 120V) 1400W run

Tools & outdoor Circular saw 1400W run / 2300W start Air compressor (1 HP) 1500W run / 3000W start Welder (140A MIG) 3500W run / 4000W start

RV & camping RV air conditioner (13,500 BTU) 1300W run / 2900W start RV converter/charger 500W run Electric griddle 1200W run Slow cooker 250W run

Power stations that fit

Right size: Expandable home backup (≈6,000Wh+) · 5,000W

Typical price $3,500-6,000+ · e.g. EcoFlow Delta Pro Ultra, Bluetti AC500 + B300S (stackable)

Runs this load ~3.1 h on a full charge.

See current prices on Amazon

This site earns commissions from qualifying purchases made through links to Amazon and other retailers, at no extra cost to you. Wattage figures are typical estimates — actual draw varies by model. Always verify against your appliance's nameplate, and consult a licensed electrician for any panel or hardwired connections.