How long will a Bluetti Apex 300 run a gas combi boiler?
A little over a day — 29 h 59 min typically, from 28 h 13 min in the worst case to 31 h 44 min at best. That assumes a gas combi boiler pulling 85 W for 60% of the time (average 51 W), plus the station's 16 W AC mains socket overhead — 67 W in total out of 2,009 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
| Setup | Average draw | Cautious | Typical | Best case |
|---|---|---|---|---|
| 1 × gas combi boiler, UK 230 V | 67 W | 28 h 13 min | 29 h 59 min | 31 h 44 min |
| 2 × gas combi boiler, UK 230 V | 118 W | 16 h 1 min | 17 h 1 min | 18 h 1 min |
| 1 × gas combi boiler, US 120 V | 67 W | 28 h 13 min | 29 h 59 min | 31 h 44 min |
- 3.8 nights of eight hours, or 1.25 days of continuous running.
- Usable energy: 2,009 Wh of the 2,764 Wh on the box, after chemistry, inverter losses and the reserve.
- To keep it going for a full 24 hours you would need about 2,213 Wh of rated capacity — which this station has.
- Start-up: the gas combi boiler asks for 85 W at switch-on against this station's 7,680 W peak — comfortable.
Buy the Bluetti Apex 300
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.
Amazon links are affiliate searches for a type of product, not endorsements of a model; the site may earn a commission at no extra cost to you.
More: How to keep warm in a power cut, and the power cut essentials list (US edition).
What changes the answer
| If instead… | Typical runtime | Change |
|---|---|---|
| The pack is two years old | 27 h 35 min | -8% |
| The pack is five years old | 23 h 59 min | -20% |
| It is −10 °C outside | 25 h 29 min | -15% |
| You run it flat, no reserve | 33 h 19 min | +11% |
| You keep 20% back | 26 h 39 min | -11% |
If you need it to run longer
These run a gas combi boiler for at least twice as long as the Bluetti Apex 300 does, cheapest first.
| Station | Wh | Typical | Indicative price |
|---|---|---|---|
| Zendure SuperBase V6400 | 6,438 | 2 days 13 h | £3,699 / $3,999 |
Smaller options that still work
| Station | Wh | Typical | Weight | Indicative price |
|---|---|---|---|---|
| Dabbsson DBS2300 | 2,330 | 26 h 28 min | 25 kg | £1,499 / $1,599 |
| DJI Power 2000 | 2,048 | 23 h 38 min | 22 kg | £1,299 / $1,399 |
| Bluetti Elite 200 V2 | 2,073 | 23 h 32 min | 24.5 kg | £1,199 / $899 |
| EcoFlow DELTA 3 Max | 2,048 | 23 h 16 min | 20.3 kg | £1,199 / $1,499 |
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