The life you're building
starts with the right system.
For van builders, motorhome owners, and 4x4 adventurers. Plan, build, monitor, and travel — all context-aware, all interconnected.
Sarah had a spreadsheet with 47 tabs and still didn't know if 200Ah was enough — had her full system spec in 12 minutes.
“Your fridge is 60W running 24h. That's 1,440Wh a day. With 5h of sun you need at least 360W of panels just to break even on the fridge alone.”
— Watt, Watt to Sarah, planning her first van build
Load calc · Cable checker · Build guide · Trip planner
Size your system in 60 seconds — no sign-up needed
Tell us your rig type, your region, and what you want to run
You're not building alone.
A build-aware community, not a forum. Real builders, real rigs, real answers.
Real builds.
Real people. Verified.
Every build is submitted by the builder, reviewed by the community, and verified against real specs. No marketing fluff.
Montana Off-Grid Cabin
Jake R. · Bozeman, Montana
800W
solar
300Ah LiFePO4
battery
4 days
autonomy
$4,200 USD
cost
“The community helped me size this correctly. First attempt, no mistakes.”
Join the home of off-grid
Free forever. No credit card. Your rig, your community, your home base.
Real builds. Real problems.
Watt finds what you miss.
This is a real community rig — with a real flaw Watt identified. Not a demo. This is what proactive monitoring looks like.
Dave's Transit Build
Dave M. · Victoria, AU
Vehicle
2019 Van / Transit
Battery
200Ah LiFePO4
Solar
400W (2×200W)
MPPT
Victron SmartSolar 100/30
312
Days off-grid
1.4kWh
Avg daily use
18
Trips completed
2.4k
Community views
Flaw identified
Thermal risk under peak loadMPPT output cable
6mm² cable on a 30A MPPT output — should be 10mm² for that run length
Watt
2 days ago
I noticed the cable between your MPPT and battery is 6mm² over a 2.1m run. At peak solar output your 30A controller can push close to its li...
Dave M. replied
“Watt caught this before I did — I'd been ignoring a slight warmth on that cable. Ordered the 10mm² today. Exactly the kind of thing I'd never have spotted myself.”
Watt monitors every connected rig proactively — not just when you ask. Dave's build is one of 10,000+ in the community.
Seven pillars. Two foundations.
Everything built around your context.
Understand, plan, monitor, and travel — all context-aware, all interconnected. Underpinned by a build-aware community and a support engine that knows your system.
Your system planned from real context — everything interconnected.
Generic tools give you a number with 30% padding. We know your exact loads, your location's solar hours, your cable runs, your fuse ratings, and your local regulations — and they all talk to each other. Change your battery size and the cable checker updates. Add a load and the component wizard re-filters. It's not a calculator — it's a living plan built around your actual rig.
Watt Architect — Your Real Daily Draw
Add every appliance, set hours per day, get your exact watt-hour requirement. No guessing, no padding.
Component Wizard — Pre-Filtered to Your Numbers
Every product shown has already been screened against your calculations. No incompatible gear, no expensive mistakes.
Cable & Fuse Checker — Regulation-Aware
Not just a size — the right size for your run length, ambient temp, install zone, and local wiring standards.
Everything Interconnected — Change One, Update All
Your loads, location, solar hours, cable runs, and regs all talk to each other. One source of truth for your whole system.
The Difference
Generic answers vs.
answers built for you.
Every other platform gives you the same answer as everyone else. We give you the answer for your system, your location, your loads.
"How big a battery do I need?"
→ "200Ah should be fine, add 20% buffer." No knowledge of your fridge wattage, your location's sun hours, your cable losses, your charge sources, or your local regulations. An educated guess with fat thrown in.
"How big a battery do I need?"
→ We know your 6 loads (187Wh/day), your location (3.4 peak sun hours), your MPPT efficiency, your alternator input, and your Queensland wiring regs. Answer: 150Ah LiFePO₄. Not 200Ah with padding — 150Ah because that's what your system actually needs.
Common questions
Quick answers before you dive in
From your first idea
to your hundredth sunrise off-grid.
Seven pillars. Two foundations. Everything adapts to your rig, your skill level, and your location. And everything you give back makes it better for the next builder.
Underpinned by Community + Ask Watt — you're never building alone