How Long Will It Run

How long will an EcoFlow DELTA Max 1600 run a gas combi boiler?

About 17 hours — 17 h 14 min typically, from 16 h 13 min in the worst case to 18 h 15 min at best. That assumes a gas combi boiler pulling 85 W for 60% of the time (average 51 W), plus the station's 13 W AC mains socket overhead — 64 W in total out of 1,103 usable watt-hours.

The gas makes the heat, so a battery only has to run the fan, pump and controls. Most boilers are wired into a fused spur rather than a plug, and some will not light on a station’s ungrounded output — read the boiler guide before relying on it.

Before you rely on it

The battery is the easy part. Most boilers are wired into a fused spur with no plug, and some will not light on a station's floating output because they sense the flame through earth. The boiler guide explains both problems and who can fix them.

The numbers

EcoFlow DELTA Max 1600 · 1,602 Wh · new pack at 20 °C, 10% reserve
SetupAverage drawCautiousTypicalBest case
1 × gas combi boiler, UK 230 V64 W16 h 13 min17 h 14 min18 h 15 min
2 × gas combi boiler, UK 230 V115 W9 h 2 min9 h 35 min10 h 10 min
1 × gas combi boiler, US 120 V64 W16 h 13 min17 h 14 min18 h 15 min
  • 2.2 nights of eight hours, or 0.72 days of continuous running.
  • Usable energy: 1,103 Wh of the 1,602 Wh on the box, after chemistry, inverter losses and the reserve.
  • To keep it going for a full 24 hours you would need about 2,114 Wh of rated capacity — 1.3× this station.
  • Start-up: the gas combi boiler asks for 85 W at switch-on against this station's 4,600 W peak — comfortable.

Buy the EcoFlow DELTA Max 1600

Where to buy

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If this is for a power cut

Heating is what a battery does worst. In a power cut, warming people rather than rooms goes much further, and none of this needs a socket.

Without a power station: a 20,000 mAh power bank runs a USB heated throw for about 7 h 24 min. See the power bank numbers.

Hot water bottle and a vacuum flask. Boil water while you still can, keep it hot in a flask, and refill the bottle through the night.

Look for: A bottle made to BS 1970 in the UK, and a flask of a litre or more.

Hand warmers. Air-activated packs give hours of heat with no power at all, and a pocketful helps children and older relatives.

Look for: Long-duration packs, and the expiry date on bulk boxes.

Battery carbon monoxide alarm. Anything burning fuel indoors, a boiler relit after an outage included, can produce carbon monoxide you cannot see or smell.

Look for: A sealed long-life battery and EN 50291 certification in the UK (UL 2034 in the US).

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More: How to keep warm in a power cut, and the power cut essentials list (US edition).

What changes the answer

If instead…Typical runtimeChange
The pack is two years old15 h 52 min-8%
The pack is five years old13 h 47 min-20%
It is −10 °C outside13 h 47 min-20%
You run it flat, no reserve19 h 9 min+11%
You keep 20% back15 h 19 min-11%

If you need it to run longer

These run a gas combi boiler for at least twice as long as the EcoFlow DELTA Max 1600 does, cheapest first.

StationWhTypicalIndicative price
EcoFlow DELTA Pro3,60037 h 55 min£2,499 / $2,699
EcoFlow DELTA Pro 34,09641 h 56 min£2,799 / $3,199
Anker SOLIX F38003,84040 h 27 min£2,999 / $3,499
Zendure SuperBase V46004,60847 h 10 min£2,999 / $4,999

The cheapest step up: EcoFlow DELTA Pro

Amazon and approved-programme links are affiliate links; the site may earn a commission at no extra cost to you. Links marked “official site” are untracked. Prices and stock change constantly — check before you buy.

Smaller options that still work

StationWhTypicalWeightIndicative price
VTOMAN FlashSpeed 15001,54817 h 52 min17 kg— / $620
VTOMAN Jump 18001,54817 h 52 min17.5 kg— / $999
Pecron E1500LFP1,53617 h 43 min17.4 kg— / $549
Bluetti AC2401,53617 h 10 min33 kg£1,099 / $999