Diesel heater on a portable power station
Freedom camping in the Mackenzie in July, or a cold night at a DOC campsite with no power? A 2 kW diesel air heater burns diesel for heat and only uses 12 V electricity for its fan, fuel pump and glow plug: about 6–31 W once running, with a start-up spike of up to roughly 100–150 W for the first few minutes. That makes it one of the few heaters a portable power station can genuinely run all night. QuietWatt’s honest answer, using the ratings Eberspächer, Webasto and NZ retailers publish.
Step 1: what a 2 kW diesel heater draws from 12 V
Electrical draw per the maker’s data sheet or the NZ retailer listing (checked 2 Nov 2026). These are not QuietWatt measurements:
- Eberspächer Airtronic S2 D2L (12 V): start up to 100 W, low 6 W, high 31 W; heat 850–2,200 W; diesel 0.1–0.28 L/h. RV kit NZ$2,245 (special) — RV World NZ listing and Eberspächer manual.
- Webasto Air Top 2000 STC: rated 14–29 W (1.2–2.4 A at 12 V); Webasto’s FAQ gives 6–7 A at the start phase, then 1–2 A running — Webasto catalogue and Webasto FAQ.
- Autoterm Air 2D (12 V kit): 10–29 W; heat 0.8–2.0 kW; NZ$1,799.99. Start-up draw not listed (TBD) — Burnsco NZ listing.
- Born To Roam 2 kW (no tank): 5–35 W running, peak 90–150 W for the first few minutes while the glow plug heats; NZ$1,033.85 — Jayco NZ parts listing.
How long is the spike? Webasto’s service manual for the Air Top 2000 STC has the glow plug on from switch-on, the fuel pump starting after about 40 seconds, and the glow plug switching off about 110 seconds later on diesel — so roughly 2½ minutes of high draw per start (service manual). Other heaters: read your manual. Every restart repeats it, so a thermostat that cycles the heater off and on often costs more than one long low run.
Step 2: which station sockets can handle the start
Rule used here: the heater’s start-up current must fit under the 12 V port’s rated amps. Amps ≈ watts ÷ 12.6 V (our arithmetic): 100 W ≈ 7.9 A, Webasto’s 6–7 A as stated, 150 W ≈ 11.9 A.
| Station (official listing) | Wh | 12 V output (per listing) | Eberspächer · ≤100 W start | Webasto · 6–7 A start | Born To Roam · 90–150 W peak |
|---|---|---|---|---|---|
| EcoFlow DELTA 3 Plus (NZ store) | 1,024 | Car socket 12.6 V 10 A, 126 W max | Yes (26 W spare) | Yes | Maybe — top of the peak is over 10 A |
| Jackery Explorer 1000 v2 | 1,070 | Car port 12 V 10 A | Yes | Yes | Maybe — top of the peak is over 10 A |
| Anker SOLIX C1000 Gen 2 | 1,024 | Car outlet 12 V 10 A, 120 W | Yes (20 W spare) | Yes | Maybe — 150 W is over 120 W |
| BLUETTI Elite 100 V2 (AU) | 1,024 | Car outlet 12 V 10 A (shared DC budget) | Yes | Yes | Maybe — top of the peak is over 10 A |
| EcoFlow DELTA Pro 3 (230 V EU listing) | 4,096 | 12.6 V 30 A, 378 W total via Anderson port | Yes | Yes | Yes |
Station 12 V specs from the linked official listings, as checked for our tyre inflator page (30 Oct 2026). Jackery’s and Anker’s car-port figures are from their US listings — confirm on the NZ/AU listing. Headroom and amps are our arithmetic. “Maybe” means a heater that really peaks near 150 W can trip a 10 A socket during ignition; one that stays near 90 W won’t. Check label / listing.
Don’t run it through the AC inverter. Plugging a 230 V-to-12 V adaptor into the AC outlet keeps the big inverter on all night and wastes energy on two conversions. Use the 12 V port, or a fused 12 V lead from a station with an Anderson-style output — see Anderson vs XT60 and 12 V car charging.
Step 3: how many nights per charge (estimate)
Nights ≈ (station Wh × ~0.85) ÷ (heater average W × hours per night). The ~0.85 is a planning allowance for conversion losses, not a spec. A 1,024 Wh station gives about 870 Wh to plan with. The start spike adds only a few Wh (100 W for about 2½ minutes ≈ 4 Wh, our arithmetic), so the running draw is what matters.
Worked examples, 10-hour night, arithmetic only: Eberspächer on low (6 W): 60 Wh a night, about 14 nights. A mid setting around 20 W (inside the Webasto and Autoterm ranges): 200 Wh, about 4 nights. Flat out at 31 W: 310 Wh, about 2.8 nights. Real draw depends on how cold it is and how well the van is insulated, so treat these as upper and lower bounds.
Weekend away
Heater + 12 V fridge
A week of winter touring
Why diesel and not a 230 V fan heater off the station
Both make about 2 kW of heat. The diesel heater gets it from fuel (Eberspächer: 0.1–0.28 L/h) and asks the battery for 6–31 W. A 2,000 W electric heater asks the battery for all 2,000 W: 870 Wh ÷ 2,000 W ≈ 26 minutes on a 1 kWh station, if the inverter can even carry it. More on that: space heater in a blackout and will it boil the jug?
Low-watt electric options — an electric blanket at around 40 W on low — are the other way to stay warm on battery alone.
Safety notes
- Install the heater as its manual says, with the exhaust outside the living space, and fit a carbon monoxide alarm. A power station changes nothing about combustion safety.
- Don’t cut power while it’s running. Diesel heaters run a cool-down after you switch them off (the Born To Roam listing and Webasto manual both describe it). Switch off at the controller, wait for the fan to stop, then turn off the station’s 12 V output. Check your station’s DC auto-off setting so it can’t switch the port off mid-night.
- Eberspächer’s undervoltage cut-out is about 10.5 V; a station’s regulated 12 V port should stay above it, unlike a tired lead-acid battery on thin wire.
- Not electrical or gas-fitting advice. Check label / listing.
Where to buy (affiliate placeholders)
Tracked affiliate links will replace these placeholders once QuietWatt is enrolled in each program. Until then, use the official product URLs above and confirm the 12 V port’s amp rating and Wh on the live NZ/AU listing. Confirm your heater’s start-up draw in its manual.
Placeholder anchors: #aff-ecoflow, #aff-bluetti,
#aff-anker, #aff-jackery, #aff-amazon.
Sources
- RV World NZ — Eberspächer D2 Airtronic-2 2.2 kW 12V RV kit — start 100 W, low 6 W, high 31 W; 0.1–0.28 L/h; NZ$2,245 special (checked 2 Nov 2026)
- Eberspächer Airtronic S2 D2L manual — average 31 / 6 W, ≤100 W while starting; undervoltage cut-out ~10.5 V
- Webasto marine catalogue — Air Top 2000 STC — rated 14–29 W, 1.2–2.4 A at 12 V
- Webasto diesel heating FAQ — 6–7 A at initial start, then 1–2 A running
- Webasto Air Top 2000 STC service manual — fuel pump after ~40 s, glow plug off ~110 s later (diesel)
- Burnsco NZ — Autoterm 2D diesel heater 12V kit — 10–29 W, 0.8–2.0 kW, NZ$1,799.99
- Jayco NZ parts — Born To Roam diesel heater 2 kW — 5–35 W, peak 90–150 W first few minutes, NZ$1,033.85
- EcoFlow DELTA 3 Plus (NZ store) — car output 12.6 V, 10 A, 126 W max; 1,024 Wh
- Jackery Explorer 1000 v2 — car port 12 V 10 A; 1,070 Wh
- Anker SOLIX C1000 Gen 2 — car outlet 12 V 10 A, 120 W
- BLUETTI Elite 100 V2 (AU) — 1,024 Wh; 12 V/10 A car outlet per BLUETTI spec sheet
- EcoFlow DELTA Pro 3 (EU) — 12.6 V/30 A 378 W via Anderson port; 4,096 Wh