Build your perfect
12V touring system
Work out the right battery, solar, DC-DC charger and inverter for your 4WD, caravan or camper — using your actual gear and how you really travel, not best-case guesses.
Everything you need to size a reliable system
Each recommendation shows the numbers behind it, so you can check the reasoning instead of trusting a black box.
Battery sizing
Works out the capacity you need from your real daily draw, your battery chemistry and how long you sit without a charge.
Solar sizing
Sizes the array for your season, regulator and how much shade you camp in — not a best-case lab figure.
DC-DC charger
Recommends a charger based on your driving time and the battery's charging limits.
Daily power use
Add your fridge, lights, Starlink and 240V appliances, then tune the run hours to match how you actually camp.
From the tracks
Built from real camping, not catalogue figures
AMP'D started with the same questions most campers have: how long will the fridge run, is the battery big enough, and will the solar keep up when the weather turns?
The calculator combines practical 12V experience with conservative system losses, so the result is useful in the bush—not just perfect conditions on paper.
Why AMP'D 12V?
Most calculators either oversimplify your setup or quietly oversize every component. This one uses transparent, real-world assumptions — derated solar, honest charger limits, and battery figures that account for how deep you can actually discharge.
- Built around Australian touring conditions
- Real-world appliance draw, adjustable to your run hours
- Brand-neutral — the maths comes first
- Free to use, nothing to sign up for
- Works for 4WDs, campers and caravans
Build your system in three steps
Add your gear
Pick your fridge size, then add lights, Starlink, CPAP, a 12V oven or anything running through an inverter.
Tell us how you travel
Driving hours, season, shade, battery chemistry and how long you'll go between charges.
See your system
Battery, solar, DC-DC and inverter recommendations — plus a trip simulator you can resize live.
Ready to build your 12V system?
It takes a few minutes, it's free, and everything stays in your browser.