Outer Line Adventures: Real Overland Power
Outer Line Adventures runs extended overland tours through some of Australia's most remote country — the kind of trips where reliable power isn't a luxury, it's safety-critical.
Their requirements were demanding:
- 4–6 week tours without shore power access
- Running a 60L Engel fridge/freezer continuously
- GPS tracking, satellite communication, drone charging
- Camera equipment charging overnight
- Two-person team, cooking with an induction cooktop occasionally
The Build
The Outer Line team worked with us to spec a dual-battery system with a Revolution Power 12V 200Ah LiFePO4 auxiliary battery.
Key components:
- Revolution Power 12V 200Ah LiFePO4 — main house battery
- Victron SmartSolar MPPT 100/30 — 200W roof solar
- Victron Orion-Tr Smart 12/12/30A — DC-DC charger from alternator
- Victron BMV-712 — battery monitor with shunt
Why a DC-DC Charger is Essential
One of the most important lessons from this build: always use a DC-DC charger between your starter battery and lithium house battery.
Without a DC-DC charger, a lithium battery connected directly to the alternator will draw maximum current as soon as the engine starts — lithium's high charge acceptance rate means it can demand more current than the alternator can safely provide. This overheats the alternator and may void its warranty.
The Victron Orion-Tr Smart limits charge current to 30A and isolates the two batteries, protecting both the alternator and ensuring the starter battery retains enough charge to start the vehicle.
Performance in the Field
After 8 weeks of testing across the Kimberley and Top End:
- Fridge ran continuously — even on heavily clouded days, the solar kept up
- 3 days of autonomy without solar — from a single 200Ah charge
- Zero battery issues — BMS handled one short circuit event without damage
- Weight saving vs AGM — 10kg lighter than equivalent AGM capacity, noticeable on corrugated roads
What Outer Line Would Do Differently
The only change they'd make is adding a second 200Ah battery for longer solar-free stretches in dense tree cover (common in Arnhem Land). Their recommendation: if you're planning extended remote touring, size for 4 days of autonomy without solar.
Building Your Own Touring System
The principles from the Outer Line build apply to any serious 4WD touring setup:
- Battery first — size for your real daily draw, add 30% buffer
- Solar — 200W minimum for the tropics, 300W for higher latitudes
- DC-DC charger — always, without exception, for lithium
- Battery monitor — a shunt-based monitor like the Victron BMV gives you real state of charge, not just voltage
Our team can spec a complete system for any vehicle and touring style. Contact us with your vehicle, fridge size, and typical trip duration and we'll design the right setup.