Free-camping for weeks means your house battery alone keeps the fridge cold and the lights on. Wattonomy sizes your lithium bank, solar and DC-DC charger to how you actually tour, and specs the fused, AS/NZS-referenced wiring to match.
A real Wattonomy output — a touring caravan house bank
System
12 V
Battery
5.12 kWh
Solar
600 W
Inverter
MP 12/1600
SmartSolar 100/501×
200W solar panel3×
Battery → inverter cable4×
Battery → inverter fuse1×
Wire & fuse sizes follow AS/NZS 3001.2 — each conductor carries its fuse and stays under a 3% voltage drop.
Built to AS/NZS standards
Gauge · fuse · volt-drop sized
Every spec sourced
A flat battery in the bush ends the trip.
Out past the last powered site, the fridge, lights and water pump all lean on the house battery — and the alternator only tops it up while you drive. Wattonomy sizes the bank to your real days off-grid, matches the DC-DC charger to your alternator, and keeps lithium out of the living area per AS/NZS 3001.2.
What an Aussie touring rig has to get right
Long stints off the grid and big distances between towns change the maths.
House battery
Sized to your days free-camping on honest lithium depth-of-discharge — kept off the starter battery.
Charge while you drive
A DC-DC charger (Redarc/Enerdrive-style) turns alternator running time into a charged bank, balanced with roof solar.
Lithium placement
Per AS/NZS 3001.2, lithium stays out of the living area unless in a sealed, vented enclosure — we flag it.
Sized wiring
Every run gauged for current and voltage drop, referenced to AS/NZS 3008.
What you walk away with — free
A house-bank + solar design sized to your real days off-grid
DC-DC / alternator charging worked into the plan
A wiring diagram with gauges and fusing
A parts list you can take to any 12V shop
Building it for real? Unlock the build binder.
Free gets you a safe, correctly-sized design. The build binder gets you the documents to build it right — and prove it's right.
Printable wiring diagram, yours to keep & tape inside the caravan
Full parts list, every line sourced
The volt-drop & fusing calculation trail — the "why" behind every spec
The build binder is a one-time unlock — no subscription, no auto-renew.
Questions
Does it size the DC-DC charger?
Yes — it matches the DC-DC charger to your alternator and battery so you actually recharge while you drive, on top of solar. Charging never shrinks the battery you carry.
Is the wiring to Australian standards?
Cable and fusing are sized using the AS/NZS 3008 method and the design flags AS/NZS 3001.2 lithium-placement rules, so you or your auto electrician can check it. It is a design aid, not a substitute for a licensed electrician on the 240V side.
AGM or lithium?
It sizes around modern lithium usable depth-of-discharge by default — roughly 200Ah lithium does the work of about 360Ah AGM.
Do I need an account?
No — design free, no email. Accounts only for saving builds or the build binder.
The standards we build to
Plain version: these are the recognized rulebooks your design is sized against, so the numbers hold up to a surveyor, an inspector or an insurer.
AS/NZS 3001.2The Australian standard for RV/caravan electrical, including lithium placement.
AS/NZS 3008The Australian cable-selection standard — current rating and voltage drop.
Wattonomy applies these standards in its calculations. It is not certified, sponsored or endorsed by ABYC, ISO, NFPA or Victron — it sizes your design to meet what they require, and shows the working.
Sized and checked to AS/NZS 3008. Last reviewed June 2026 — see the full methodology for the exact rules behind every number and how each design is validated.
Built by anABYC Certified Master Technician