Scenarios › Power station for a space heater (1500 W)
What size power station runs a 1500 W space heater?
Be warned: resistive heat is the worst-case battery load. A 1,500 W heater needs a 1,500 W+ inverter and drains capacity fast — run time is roughly usable Wh ÷ 1,500. Here is the honest math, plus far more efficient ways to stay warm in an outage.
5,000 Whcapacity needed
1,500 Wrunning watts
1,500 Wsurge to clear
3.0 hruntime horizon
This load: Space Heater (1500 W). Want to tweak it? Open the full sizing tool and adjust the appliances and hours.
What size you need
This is a big load — about 5,000 Wh over 3.0 h. No single portable battery holds that much, but the expandable systems below meet the power draw (1,500 W running, 1,500 W surge) — add a battery module to reach the full watt-hours. This is the expandable-system territory most partial- and whole-home backup lives in.
The math
Running watts (everything on at once) = 1,500 W
Surge watts (worst single startup + the rest running) = 1,500 W
Average draw (cyclic loads counted by their duty cycle) = 1,500 W
Watt-hours = 1,500 W × 3.0 h ÷ 90% usable reserve = 5,000 Wh
1
EcoFlow DELTA Pro 3best expandable match
4,096 Wh 4,000 W cont · 8,000 W surge expandable ~2.5 h on this load $$$
A 4 kWh, 4,000 W (120/240 V) system built specifically for whole-home backup.
LiFePO4 · AC/solar/EV; expandable to 48 kWh · 113 lb
2
Goal Zero Yeti PRO 4000
3,993 Wh 3,600 W cont · 7,200 W surge expandable ~2.4 h on this load $$$
Goal Zero’s LiFePO4 flagship — 4 kWh, 3,600 W, whole-home with the transfer switch and tanks.
LiFePO4 · Fast AC; expandable to ~27 kWh · 104 lb
3
Anker SOLIX F3800
3,840 Wh 6,000 W cont · 9,000 W surge expandable ~2.3 h on this load $$$
A 6,000 W, 240 V system for whole-home backup including a well pump and electric range, expandable to ~27 kWh.
LiFePO4 · 120/240 V; expandable to 26.9 kWh · 132 lb
4
EcoFlow DELTA Pro
3,600 Wh 3,600 W cont · 7,200 W surge expandable ~2.2 h on this load $$$
The whole-home contender on wheels — 3,600 W, expandable to 25 kWh, panel-ready with a transfer switch.
LiFePO4 · AC + EV charging; expandable to 25 kWh · 99 lb
5
Bluetti AC300 + B300
3,072 Wh 3,000 W cont · 6,000 W surge expandable ~1.8 h on this load $$$
A modular 3 kW system with a sub-20 ms UPS switch — toward whole-home with a transfer switch.
LiFePO4 · Modular; expandable to 12.3 kWh, 24/7 UPS · 116 lb
6
Goal Zero Yeti 3000X
3,032 Wh 2,000 W cont · 3,500 W surge expandable ~1.8 h on this load $$$
Three kWh on wheels for multi-day essentials backup.
NMC · AC/solar; integrates with home kit · 70 lb
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Disclosure.
The load, appliance by appliance
⚡ Informational only — a computed sizing estimate from published appliance-wattage charts and manufacturer station specs. It is not an electrical guarantee. For hardwired or whole-home backup, transfer switches, or any permanent install, consult a licensed electrician. Appliance wattages are representative chart values and vary by model; check your nameplates. Duty cycle (how much of the time a load actually draws) is how we keep the watt-hour estimate from overselling capacity.
Common questions
What size power station runs a 1500 W space heater?
For Space Heater (1500 W) over 3.0 h you need about 5,000 Wh — more than a single portable battery holds. Use an expandable system that meets the 1,500 W surge (like the EcoFlow DELTA Pro 3) and add a battery module to reach the full capacity.
How many watt-hours does this load need?
About 5,000 Wh for 3.0 h — we take the duty-weighted average draw (1,500 W, since cyclic loads like fridges and pumps don't run constantly), multiply by the hours, and divide by a usable-capacity reserve. Running watts are 1,500 W; surge is 1,500 W.
Other scenarios
Sources: appliance wattages — standard appliance/generator sizing charts; station specs — manufacturer published specifications (compiled 2026-06-15; approximate). Informational only — a computed sizing estimate from published appliance-wattage charts and manufacturer station specs. It is not an electrical guarantee. For hardwired or whole-home backup, transfer switches, or any permanent install, consult a licensed electrician.