Van Life Power Budget: A Realistic Daily Watt-Hour Worksheet

Why Most Van Power Budgets Fail

They fail in one of two directions. Optimists add up the loads they remember, forget the fridge runs while they sleep, and buy a station one class too small. Pessimists read a forum thread, conclude they need 600Ah of lithium and an alternator charger, and spend $4,000 solving a $1,200 problem.

The fix is a line-item worksheet: list every load, multiply draw by hours by duty cycle, sum it, divide by 0.85 for inverter losses, and match the result to a station class. Twenty minutes of arithmetic replaces both failure modes. This post builds the worksheet; the runtime calculator automates it.

The Worksheet: Line Items That Cover 95% of Van Builds

The formula per line: delivered Wh = watts × hours × duty cycle. Duty cycle matters only for thermostatic loads (fridges) — everything else is 100% while in use.

#	Load	Draw	Hours/day	Duty	Delivered Wh/day
1	12V compressor fridge	60W	24	40%	576
2	Laptop (work hours)	60W	4	100%	240
3	Starlink (if working remote)	75W	6	100%	450
4	Phones (2 people × 2 charges)	15Wh/charge	—	—	60
5	Lights (LED string/puck)	20W	4	100%	80
6	Vent fan	15–30W	8	100%	~180
7	Water pump, misc 12V	—	—	—	~50
8	Coffee, 1 pot (drip)	950W	~10 min	100%	160

Three profiles fall out of which lines you include:

Profile	Lines included	Delivered Wh/day	Rated capacity needed (÷0.85)
Weekender (no remote work)	1, 4, 5, 6, 7	~946	~1,115
Remote worker	all eight	~1,796	~2,113
Minimalist (cooler, no fridge)	4, 5, 6, 7	~370	~435

The pattern worth internalizing: the fridge is a third to a half of almost every realistic budget, and Starlink is the second-biggest line the moment work enters the picture. If you're running the dish, read the dedicated breakdown in Can It Run: Starlink — the workday math deserves its own page.

Matching the Number to a Station Class

The rule: your station's rated Wh should cover one full day at minimum, because solar income is never guaranteed. Margin beyond one day buys weather insurance.

Minimalist (~435Wh/day): 500Wh class

The Goal Zero Yeti 500X (505Wh, 300W AC, 12.9 lbs, WattScore 72) covers the no-fridge budget with a sliver of margin. Its NMC chemistry and 300W inverter are dated — but for a lights-fan-phones van, it's sufficient.

Who it's for: weekend vans with a cooler instead of a fridge. If you're buying new and prices are close, stepping to a 1kWh LFP unit future-proofs the inevitable fridge purchase.

Weekender (~1,115Wh/day): 1kWh class — barely

A EcoFlow DELTA 2 (1,024Wh, 1,800W AC, 27 lbs, WattScore 88) lands about 90Wh short of the weekender budget on paper — close enough that driving (12V charging while in motion) or a single panel closes the gap daily. Its 1,800W inverter also covers the coffee line and any future kitchen ambitions.

Who it's for: weekend and part-time vans with a fridge. The honest caveat: zero-margin sizing means a cloudy, stationary Saturday ends with a warm fridge Sunday morning. If your trips are stationary, size up.

Remote worker (~2,113Wh/day): 2kWh class

This is the budget that surprises people — work-from-van roughly doubles the weekender number. The 2kWh class fits it with thin margin:

Station	Wh	Usable (×0.85)	vs. 1,796Wh/day delivered	Solar in	lbs	WattScore
Jackery Explorer 2000 Plus	2,042	1,736	0.97 days	1,400W	61.5	89
Bluetti Elite 200 v2	2,073	1,762	0.98 days	1,000W	53.4	88
Anker SOLIX F2000	2,048	1,741	0.97 days	1,000W	67.2	85

All three are one-day units against this budget, which means solar isn't optional at this tier — it's the other half of the system. The Explorer 2000 Plus's 1,400W input ceiling is the differentiator: more panel headroom equals faster recovery on marginal days. The Elite 200 v2 counters with 8–14 lbs less weight and a 70-minute 0–80% wall charge for pedestal stops. The F2000 is the pick only when discounted.

Who they're for: full-time and work-from-van builds. Pick by your recharge style — big solar: Jackery; frequent shore stops: Bluetti.

Margin buyers: 4kWh

The EcoFlow DELTA Pro 3 (4,096Wh, 4,000W, 113.5 lbs, WattScore 92) holds roughly two remote-work days. In a van, its weight demands a permanent mount and its price overlaps DIY 12V house-battery territory — the honest comparison at this tier isn't between stations, it's between a station and a built-in system. The station wins on zero-install and portability between vehicles; DIY wins on cost per Wh.

Who it's for: full-timers in cloudy regions who want two-day autonomy without touching a crimper.

The Solar Replenishment Side of the Ledger

A budget has two columns. Income: panel watts × 0.7 real-world derate × sun hours. The 0.7 covers heat losses, off-angle mounting, and morning/evening ramp — flat van-roof mounts often do worse; tilted ground panels do better.

Array	Real output	4 sun hours yields	Covers which profile?
200W	140W	560Wh	Minimalist, plus margin
400W	280W	1,120Wh	Weekender (exactly)
800W	560W	2,240Wh	Remote worker (just)

Read the third row carefully: a remote worker needs ~800W of panel and four good sun hours to break even daily. That's most of a long-wheelbase van roof, or a roof array plus deployable ground panels. With 400W, a remote worker runs a ~900Wh daily deficit — about two days until empty, which is fine for a workweek punctuated by a campground stop, and not fine for indefinite boondocking.

Driving helps less than people hope: a 12V socket delivers 100–120W, so two hours of driving returns ~220Wh — real, but a fraction of one sun-hour on a proper array. (Dedicated DC-DC alternator chargers change this math substantially, but that's an install, not a station feature.)

Build Your Own: The Five-Step Procedure

1. Inventory every load — check nameplate watts, don't guess. The fridge label, the laptop brick, the fan spec sheet.
2. Assign honest hours and duty cycles. The fridge runs 24h at ~40%. Your laptop runs your actual work hours, not your aspirational ones.
3. Sum delivered Wh, divide by 0.85 to get rated capacity per day.
4. Pick the class that covers ≥1 day, then add margin for your weather and recharge pattern.
5. Size the panel array to your daily total using the 0.7 derate and your region's realistic sun hours — winter sun hours, if you van in winter.

Then sanity-check the candidate units against the full spec table in our station database, and stress-test your numbers in the runtime calculator. Our modeling assumptions are documented in the methodology.

FAQ

Why divide by 0.85 — where does that energy go?

Inverter conversion losses, BMS overhead, and self-consumption while the unit is on. Rated watt-hours measure the battery; you can only use what survives conversion. Running DC loads (fridge, USB) directly off the DC bus loses less than 15%, so a heavily-DC budget gets slightly better than our model — treat the 0.85 as conservative.

Should I just build a DIY 12V system instead of buying a station?

Below ~2kWh, the station wins for most people: no install, full warranty, an inverter and MPPT included, and it moves to your next vehicle. Above ~4kWh of need, DIY's lower cost per Wh starts to dominate. The 2–4kWh zone is a genuine toss-up decided by whether you want to do electrical work.

How much margin should I add to the worksheet total?

Add 20% if you have reliable solar and move often (driving charge opportunities). Add 50–100% if you park for days in variable weather. Margin is cheaper than the failure mode — a warm fridge or a missed workday.

Does cold weather change the budget?

Yes, twice over: LFP stations charge poorly below freezing (most refuse or throttle charging until the cells warm), and the vent-fan line often becomes a heater line. Winter vanlifers should treat their worksheet total as a floor and keep the station inside the insulated envelope of the van.