What the spec sheet says vs. what we actually got.
Eight years, one ProMaster, real climates. Every number below is from gear we owned and ran, not a launch-week press kit.
MaxxAir publishes no amp draw at all. Every figure in circulation is third-party, and we put a meter on ours.
On 12V, low setting. It spikes past the plate for the first minute of a cool-down, then holds 45W until it hits temperature and shuts off. Neither number is what your battery sees: the compressor duty-cycles, and that averages out to 20–25 Wh/hr in Florida heat.
Full sun on the panels, controller sitting there doing nothing. Dead until we hauled it indoors to thaw.
It faded gradually across seven years of full-time use. The sharp drop came after eight months sitting in storage, not from the road.
This spec was accurate. What nobody prints is what it buys you: a two-hour coffee shop stop, and 8% to show for it.
Five numbers, one van, eight years. Every one is sourced below, and every one is free to cite. Tap See the receipts under any section for conditions, instrument and method.
Roof fan draw: the number MaxxAir doesn't publish
Not on the product page, not in the install manual. Every figure in circulation is third-party, and they disagree with each other at the top of the range. So we put a meter on ours.
See the receipts +
| What we ran | Spec / claim | What we measured | Conditions | Source |
|---|---|---|---|---|
| MaxxAir 4500 & MaxxFan Deluxe 7500, one fan at speed 10 | Reported MaxxAir publishes none. Third-party tables say 3.7–4.4A, or 44–53W. | Measured 32W, about 2.7A at 12V. Both fans read the same figure, so the 7500's rain dome costs airflow rather than watts. | Read at the power station's DC output. Unchanged blowing out or blowing in, and unchanged with the T-vent windows open or shut. It is the motor, not the airflow path. | 8-year MaxxAir review |
| Both fans together, speed 10 | Estimate 64W, if you assume two fans cost double one | Measured 58W. The pair consistently drew a few watts under double a single fan, in every configuration we tried. | We cannot fully explain the gap. A fixed overhead inside the station being counted twice would fit the arithmetic, but the unit reads 0W with nothing connected, which rules that out. Reported as measured. The practical note: a power budget built by summing devices you measured one at a time can come out a little high. | Best van fans |
On the instrument, because it matters: this is a power station's own DC output readout, not a bench meter. Call it ±5%. It is still the only measured figure we can find for this fan anywhere, including from MaxxAir, and it is repeatable across configurations. Eight hours wide open works out to about 256Wh per fan, or 464Wh for the pair.
Where the 240 to 380Wh comes from: two fans at the third-party range is 88 to 106W. Ours measured 58W for the pair. Over an eight-hour night that is 240Wh at the bottom of the range and 384Wh at the top.
Recharge speed: the number that decides your week
Whether a cloudy stretch wrecks you comes down to this one figure. Going from the Yeti to the Elite turned a full-day charge into a lunch break.
See the receipts +
The Yeti's Spec 60W input capped it near 25 hours wall-to-full. Coffee-shop top-offs netted only about 8% per two hours, so a three-hour session recovered roughly 150 to 200Wh.
The Elite's Spec 1800W input refills the whole day over a lunch break, about an hour to 80%.
Sources: Yeti 1400 review · Elite 200 V2 review · what I wish I'd known
Fridge draw: the climate sets the number
The figure every "how many watt-hours do I need" calculator gets wrong, because they use a rated number instead of a lived one.
What it pulls with the compressor actually running
Measured on 12V, low setting.
See the receipts +
The two numbers are the same fridge, measured two different ways, and mixing them up is the most common power-budgeting mistake we see. 45W is the compressor's draw while it runs. 20 to 25 Wh/hr is what a whole hour costs once you account for the compressor being off most of that hour. Multiply 45W by 24 and you get 1,080Wh, roughly double the real cost of a hot day and about four times the cost of a mild one.
What the climate changes is how often the compressor runs, not how hard it pulls while running. That is why the same fridge costs twice as much in Florida as it does in mild weather.
What we are deliberately not publishing: a duty-cycle percentage. You can divide the hourly average by the running draw to get one, and we did that at first. It does not hold up. The 45W is a spot reading on 12V at the low setting, while the hourly averages are long-run figures from years of normal use with no operating mode recorded. Dividing one by the other mixes two different conditions and produces a number that looks precise and is not. Low mode plausibly runs the compressor gentler for longer, which would change the answer. Timing the compressor over a full hour is the honest way to get that figure, and we have not done it yet.
Plan a fridge from the manufacturer spec sheet and you'll pencil in a 10 to 15W average and feel conservative. In mild conditions you might be right. In a dark van in a Florida July with no shade, you are undercounting by 50 to 100%.
Over a full day in serious heat the fridge alone can eat 480 to 600Wh before you have touched a laptop, a fan or a light.
Conditions: one Dometic CFX65DZ running 24/7 in a black 2017 ProMaster, across Gulf-coast summers, Colorado winters, New York fall and Arizona dry heat. The running-draw figures were read on the BLUETTI, the same instrument as our fan numbers, so call them ±5% as well, with the fridge on 12V at the low setting.
Sources: van fridge real power draw · Dometic CFX65DZ review
Cold weather: the number nobody puts on the box
A spec sheet won't tell you the battery quits before you do.
See the receipts +
| What we ran | Spec / claim | What we measured | Conditions | Source |
|---|---|---|---|---|
| Goal Zero Yeti 1400 (NMC) | Spec lithium low-temp charge cutoff | Measured won't accept a charge once internal temp drops near freezing. Solar controller just sits there in full sun. Dead until warmed 6–24 hr indoors. | Two to three Colorado winters. Took a run of days around 20°F, not a single freezing night; we hauled the unit into a Lakewood house to thaw. | Cold weather killed my charging |
Cycle life: rated vs. what the road did
Rated cycles are a lab number. Here is what the road did to ours, and what eight months parked did after it.
See the receipts +
| What we ran | Spec / claim | What we measured | Conditions | Source |
|---|---|---|---|---|
| Goal Zero Yeti 1400 (NMC) | Spec ~500 cycles rated | Measured ~7 years full-time (2018–Nov 2025); gradual fade, then a sharp drop after 8 months in storage. Eventually zeroed out on an induction burner. | Daily cycling, all climates. Maintained at 30–80% during the storage stretch and still lost real capacity. | Yeti 1400 review |
| BLUETTI Elite 200 V2 (LiFePO4) | Spec 6,000+ cycles rated | Measured in progress, owned since Black Friday 2025. We won't fake a number we haven't lived yet. | Daily driver since the Yeti retired. We'll update this row as the years stack up. | Elite 200 V2 review |
Solar vs. driving: where the watts actually come from
The roof is already full, and it is still the small number.
See the receipts +
Two MaxxAir fans mean three panels fit. A fourth would cost a fan, so 300W is this van's ceiling no matter the budget. That constraint is the whole reason we went after alternator charging instead of a bigger array.
The BLUETTI Charger 2 is rated to move up to 1,200W combined while we drive. Spec Ours does not: since a 2026 firmware update the real ceiling is around 800W, and solar is cut rather than blended when the total goes over. Measured The readings are here.
Sources: Renogy 100W review · alternator charger changed everything
The calibration step that fixed both our stations
Both the Yeti 1400 and the Elite 200 V2 drifted on their battery-percentage readout. The fix is the same on almost any station, and it’s the first thing we do with a new unit: run a full 100% → 0% → 100% calibration cycle. Drain it under load, then refill it at a steady wattage with nothing pulling from it, starting the moment it reads zero. Do it the day you unbox.
Put these numbers to work
Every measured figure on this page feeds our 7-Day Off-Grid Simulator. Pick a station, a season and your loads, and it plays out a full week hour by hour, using this data as its inputs. It will tell you whether you make it, or the exact hour you don’t.
How we label every figure
Order of trust is measured → spec → reported → estimate.
Measured tested firsthand on our own unit · Spec manufacturer-stated · Reported third-party, not from the maker · Estimate planning figure
Rule of the house: a measured charge time and a spec charge time are not the same promise. Full methodology at how we test and label claims.
Citing this data
Writers, forum posters, fellow spreadsheet people: every number on this page is free to cite, just link back here as the source. It’s one van, one couple, and gear we paid for ourselves, labeled spec vs. measured, and we keep updating as the miles stack up.
Grab a ready-made citation, pick whichever format your platform takes:
Real-world van power data (8 years measured): recharge times, fridge draw by climate, MaxxAir roof fan draw, cold-weather cutoffs. https://www.createavanlife.com/real-world-power-data/
[Real-World Van Power Data: Measured, Not Marketed](https://www.createavanlife.com/real-world-power-data/). 8 years of measured recharge times, fridge draw, MaxxAir fan draw, and cold-weather data
<a href="https://www.createavanlife.com/real-world-power-data/">Real-World Van Power Data: Measured, Not Marketed (Create A Van Life)</a>