The short answer
A comfortable two-person weekend setup draws 60–90 amp-hours per day. That makes 200Ah of lithium genuinely comfortable, and 100Ah workable if you cook on propane. Pair it with 200–400W of solar and a 30A DC-DC charger — the alternator, not the roof, is what refills a bank fast.
Electrical is the part of a van build with the widest gap between what people install and what they use. We have seen weekend rigs carrying 600 amp-hours of lithium that never dip below 80%, and full-timers limping along on a single undersized battery. Both mistakes come from the same place: sizing the system before listing the loads.
Start with loads, not batteries
Write down everything that will draw power on a typical day, with honest hours of use. A realistic weekend list looks something like this:
- Roof fan on low overnight — roughly 15–20 Ah
- 12V fridge — 30–40 Ah per day, the biggest steady consumer in most vans
- LED lighting for an evening — 5–8 Ah
- Phones, headlamps, a laptop — 10–20 Ah
- Water pump and small electronics — a rounding error
That totals 60–90 Ah per day for a comfortable two-person weekend setup, before any induction cooking or climate equipment. Note how dominant the fridge is: it is the one load that runs whether you are awake, asleep, or out hiking.
How big should the battery bank be?
A good rule: your usable capacity should cover two days of your real total, so weather or a lazy day never forces a drive. For the list above, 200 Ah of lithium is genuinely comfortable, and 100 Ah works for minimalists who cook on propane.
Doubling that again is where budgets go to die. If you are tempted, price the extra capacity against the DC-DC charger that would have refilled the bank you already own.
Charging: solar is the supplement, driving is the workhorse
Rooftop solar earns its keep parked in the sun, but a DC-DC charger off the alternator refills a bank faster and works at midnight in the rain. Two hours of driving can put back what a full day of clouds took out. Most balanced systems pair 200–400W of roof solar with a 30A DC-DC charger, plus shore power for the nights you have a hookup.
Every Camp and Rambler ships with 200W solar, alternator charging, and shore-power charging as standard for exactly this reason — three inputs, so no single one is a point of failure.
Where a drop-in power station fits
For weekend builds, a modern all-in-one power station covers the entire list above without a custom electrical bay: inverter, charging, and monitoring in one box you can also carry to a campsite table. That is the approach our kit electrical package is designed around.
Full custom systems come into their own when induction cooking, air conditioning, or genuine off-grid work enter the picture — and they are far easier to repair in year five. We wrote about that trade-off in why we spec discrete components instead of an all-in-one.
Buy your second electrical system first: the one sized for how you actually camp, not the one sized for the trips you are still imagining.
A worked example
Two people, a long weekend, shoulder season in Colorado. Fridge 35 Ah, fan overnight 18 Ah, lights 6 Ah, devices 15 Ah — call it 75 Ah per day. Two days of autonomy means 150 Ah usable. A 200 Ah lithium bank covers it with margin, 200W of solar keeps pace on a clear day parked, and the drive to the trailhead tops it off regardless of weather.
Electrical options for both approaches are configurable on the conversion build form, and our team is happy to sanity-check a load list before you commit. Browse electrical components if you are specifying it yourself.
Frequently asked questions
How many amp hours do I need for a camper van?
A comfortable two-person weekend setup uses 60–90 amp-hours per day. Size the bank for two days of that total, so 200Ah of lithium is comfortable for most builds and 100Ah is workable for minimalists who cook on propane.
How much solar does a camper van need?
Most balanced systems use 200–400W of roof solar. Solar is a supplement rather than the primary source — a 30A DC-DC charger off the alternator refills a battery bank faster and works at night and in bad weather.
What uses the most power in a camper van?
The 12V fridge, at roughly 30–40 amp-hours per day. It is the only major load that runs continuously whether you are awake, asleep, or away from the van.
Is a portable power station enough for a van build?
For weekend use, yes. An all-in-one power station covers a typical 60–90 Ah day without a custom electrical bay. Custom systems make more sense for induction cooking, air conditioning, full-time living, or when long-term repairability matters.