Sizing your system starts with daily behavior, not product marketing. The right answer for a weekend camper is completely different from the right answer for a remote worker — and most buyers figure this out after they’ve already bought the wrong thing.
Track real device use first. Then choose capacity.
Why Raw Watt-Hours Mislead#
Marketing emphasizes total capacity. Real van life cares about usable capacity per day and how fast you get it back.
Two systems both rated at 1,000Wh can behave completely differently:
- System A charges at 1,200W (AC) and 400W (solar). Back to full in under two hours from shore or a full sun day.
- System B charges at 200W max. Takes five-plus hours to recover the same load.
If you’re parked somewhere with power every few nights, System B might work. If you’re moving daily and relying on solar or alternator, System A is a different class of tool. The number on the box doesn’t tell you this.
Build Your Daily Load Estimate#
List everything you actually run and how long you run it. Don’t estimate from memory — track for a real day if you can.
Common van loads (Estimate):
| Device | Typical Draw | Hours/Day | Daily Wh |
|---|---|---|---|
| Laptop (15") | 45–65W | 6–8 | 270–520Wh |
| Mobile hotspot / router | 10–20W | 8–10 | 80–200Wh |
| LED lighting | 5–20W | 3–5 | 15–100Wh |
| 12V fan (low–medium) | 15–30W | 6–8 | 90–240Wh |
| Phone charging | 10–18W | 2–3 | 20–54Wh |
| Coffee maker (travel) | 300–600W | 0.1 | 30–60Wh |
A typical remote worker day — laptop, hotspot, lights, fan, phone — lands somewhere between 500 and 900Wh of actual consumption. Not 1,500Wh. Not 200Wh. Right in the middle, and heavily dependent on how hot it is (fan draw), how many hours you work, and whether you’re running a heater.
Add Margin, Then Double-Check Recovery#
Once you have your daily estimate, don’t buy exactly that capacity. Add margin two ways:
Capacity margin: Buy 1.3–1.5× your daily estimate. This preserves battery health (LFP performs best when not fully cycled every day) and covers heavier days. A 700Wh daily estimate points toward a 900–1,100Wh station.
Recovery reality check: Can your charging sources recover that load in the time you have? This is where most buyers skip a step. A 1,000Wh station that only charges at 150W solar input needs nearly seven hours of full sun to refill. That doesn’t happen in most of the US outside of summer.
The Remote Worker Case#
Remote workers often assume they need massive capacity because laptops feel power-hungry. In practice, the load is manageable — but the recovery requirement is stricter than expected.
Running a laptop and hotspot eight hours a day is roughly 400–600Wh. A 700–1,000Wh station handles this with headroom. The problem is that you need that station substantially recharged by the next morning, every morning.
That makes charge rate the deciding factor — not total Wh. A 700Wh station that charges at 800W AC and 300W solar is more useful for daily remote work than a 1,500Wh station that charges at 100W solar only.
Where Most Buyers Go Wrong#
Chasing maximum Wh. Bigger sounds safer. But a large, slow-charging station leaves you anxious every cloudy day and every extended stay without power access.
Ignoring realistic solar harvest. A panel rated at 200W doesn’t deliver 200W except in ideal conditions. Budget for 60–80% of rated output on a good day, less in partial shade or overcast. If solar is your primary source, size input capacity accordingly.
Forgetting the heat and HVAC wildcard. If you’re running a 12V fan most of the night in summer, that adds 100–200Wh to your daily total quietly. Do the math with the fan on.
Quick Sizing Targets (Estimate)#
| Van Use Pattern | Daily Load Range | Suggested Station Size |
|---|---|---|
| Weekender, minimal devices | 150–300Wh | 500–700Wh |
| Part-time remote work | 400–600Wh | 700–1,000Wh |
| Full-time remote work | 600–900Wh | 900–1,200Wh |
| Heavy use (CPAP + work + cooking) | 900–1,400Wh | 1,200–2,000Wh |
These are planning ranges, not guarantees. Your actual load depends on your specific devices, climate, and habits.