A fridge eats most of a 700Wh battery before you turn anything else on.
700Wh on the label is about 560Wh you can actually use. Our fridge takes 360 of it on a normal warm day, and 528 in a Gulf-coast summer. Here is the whole budget, in real numbers.
Worth knowing before you plan: every AC load pays a translator on the way out.
Step 1 · Where the 560Wh actually goes
Every figure below is a load we run and have measured. A day is 24 hours of fridge, 8 hours of fan overnight, 5 hours of lights, and phones on the charger in the evening.
Where 700Wh becomes 560Wh+
Two deductions, and neither is a defect.
You should not run a lithium battery flat. Leaving roughly 20% in reserve is what keeps the cycle count you paid for, so a 700Wh label is about 560Wh of working capacity. Estimate
AC costs more than DC. Anything you run through the inverter pays a conversion tax on the way out. Run the fridge and fans on 12V and you keep more of the 560 than the spec sheet implies.
One piece of good news: the sub-$500 stations we actually recommend are 768Wh, not 700, so the real working number is closer to 614Wh. Every total on this page is the conservative version.
Step 2 · Pick the scenario that matches you
The same three setups, with the arithmetic done. "Days" means days from a full charge with no recovery at all.
Weekend minimalist
Phones, lights, a small fan. No fridge. This is the load 700Wh was built for, and it is genuinely comfortable.
- Fan overnight: 120Wh
- Lights + phones: 80Wh
- Makes it viable: almost anything. A drive every third day covers it.
Fridge + devices
The most common full-time setup, and the one the whole page exists for. On a warm day it spends the entire usable battery in exactly one day.
- Fridge, warm: 360Wh, before anything else runs
- Fan, lights, phones: 200Wh
- Makes it viable: recovery every single day. Not most days.
Fridge + fan + work
Full-time living plus remote work. This does not fit in 700Wh at all. You are refilling inside the day, every day, or you are rationing.
- Laptop alone: 350Wh, most of a fridge
- Everything else: 560Wh
- Makes it viable: honestly, the next tier up
The one that should stop you is Setup B. A 700Wh station running a fridge is a one-day battery. That is not a reason to avoid it. It is the reason this whole site ranks recovery speed above capacity: at this size, how fast you refill matters more than what you hold. In a Gulf-coast summer the same loads come to 728Wh and you do not finish the day at all.
Totals are Estimate, summed from the measured loads above. Your fridge, your climate and your hours will move them. Run yours in the calculator →
Step 3 · What changes your margin
Tap the factor that's eating your margin.
🌡️ Heat + humidity Fridge + fan rise
The fridge runs harder and longer; fans don't catch a break. Treat baseline cooling as non-negotiable. Comfort flexes around it.
🔌 AC vs DC routine Conversion costs
Every AC habit you don't notice (chargers, the router, an inverter left on with nothing plugged in) is paying a translator. DC-first paths stretch a small system noticeably further.
🍳 Cooking spikes Short, high-draw
An induction burner or kettle pulls hard for ten minutes and the margin's gone. Daily heavy cooking on 700Wh pushes the whole system into a different tier.
☁️ Cloudy days Refill drops
Two cloudy days and the math you trusted last week stops working. If solar is your only refill, cloudy stretches break it.
Example math (illustrative only): a 100W device on a perfect 700Wh battery looks like ~7 hours on paper. In reality you'll see less. The inverter takes a cut, and you'll want to leave some battery in reserve instead of running it flat. Use it for direction, not promises.
Step 4 · The upgrade ladder
Where each tier stops feeling fragile.
Entry baseline
Full-time minimum. Works when loads stay disciplined and recovery is reliable, and gets stressful when either slips.
- Forces routine before purchase
- Validates your workflow
- Cleaner upgrade path later
Comfort margin
Better daily margin and fewer tradeoff decisions. Sweet spot for most full-timers.
- 1–2kWh, fast wall recovery
- Stops feeling fragile
- Workday-reliable
Buffer for everything
Mixed routines, cloudy-day resilience, occasional cooking spikes handled.
- 3kWh capacity, expansion options
- 1,200–2,400W solar input, depending on the pick
- Stop counting hours until plug-in
Step 5 · Quick decision shortcut
Three lenses. Pick the one that matches.
- Outlet access weekly? Buy for fast AC recharge: plug in, top up, move on.
- Park in sun often? Get real solar capacity and keep one backup recovery path.
- Drive most days? Plan around alternator recovery first; everything else is bonus.
Not sure which lens is you? See solar vs. alternator charging.
Step 6 · Go deeper (only if you need to)
FAQ: what 700Wh covers+
Can 700Wh run a fridge overnight? Overnight, comfortably. Our fridge averages 15 Wh/hr on a warm day Measured, so twelve hours of dark costs about 180Wh of your 560. The problem was never the night. It is the other twelve hours, which cost the same again.
Why does my "700Wh" feel smaller? Because about 140Wh of it is not yours to spend. Leave roughly 20% in reserve to protect the cycle life, and anything you run through the inverter pays a conversion tax on top. Plan on 560Wh, not 700.
Is 700Wh enough for full-time? With a fridge, only if you refill every day: the loads come to 560Wh against 560Wh of usable capacity. Without a fridge it is genuinely comfortable, around 200Wh a day. The fridge is the whole question, not the laptop and not the lights.
What about cooking? A kettle is about 100Wh a go and an induction dinner about 750Wh. Estimate One induction meal is more than a whole 700Wh battery. Occasional spikes are survivable; daily electric cooking is a different tier of machine.
Bigger capacity or faster charging? For most van users, faster recovery improves day-to-day stability sooner than a moderate capacity bump alone.
Can solar alone carry it? Sometimes in ideal exposure. Mixed weather and shade usually need backup recovery.
Why we start at 700Wh++
Below 700Wh, many van routines turn into active power management instead of stable living. You spend more time deciding what to turn off and when to recharge.
At 700Wh and above, you usually get enough breathing room to validate your routine, tighten your workflow, and build a cleaner upgrade path, without the system feeling fragile.
The mistake: capacity without a recovery plan+
Capacity without refill strategy creates false confidence. A bigger battery you can't refill is just a heavier paperweight by Thursday.
Build recovery first:
- Shore when available
- Solar when harvest conditions are real
- Drive recovery when travel patterns support it