Overland power that survives the Dempster, not just the driveway
Trail rigs see vibration, cold, and long alternator runs. PowerLab sizes for real-world overlanding, not a marketing brochure.
DC-DC + alternator audit
Know exactly what your alternator can sustain. Don’t fry it feeding a 40A DC-DC on low RPM.
Trail loads covered
Fridge, roof fan, lights, winch, recovery gear, CB/ham, inverter for tools. All real amps.
Cold-weather derate
Winter overlanding — auto-derate for below-freezing battery charging and load spikes.
ABYC-grade wire runs
Marine-standard wire sizing because trail vibration is worse than most boats.
Typical loads we already model
These are realistic watt draws and duty cycles pulled from the PowerLab appliance catalog. When you start a design, you pick from this catalog and customize \u2014 nothing to re-type.
| Load | Watts | Hrs/day | Wh/day |
|---|---|---|---|
| 12V fridge (50L) | 45 | 12 | 540 |
| Maxxair roof fan | 30 | 6 | 180 |
| LED overhead lights | 40 | 3 | 120 |
| Inverter (incidental tools) | 300 | 0.5 | 150 |
| Starlink Mini | 35 | 4 | 140 |
| Ham radio (receive) | 5 | 10 | 50 |
| Winch (rare, peak 4000W) | 4,000 | 0.05 | 200 |
| Sample total | 1,380 Wh/day |
Typical real-world band for this niche: 600\u20132,500 Wh/day (midpoint 1,550). Your actual number depends on your gear and how you use it; PowerLab calculates it exactly.
Ask these once your design is loaded
PowerLab Co-Pilot sees your exact design and can answer questions in plain English. Starter prompts for this niche:
- \u203aWill my alternator sustain a 40A DC-DC charger at idle?
- \u203aWhat’s my usable battery capacity at -10°C?
- \u203aSize the winch feed wire from starting battery to solenoid.
Frequently asked
Can I skip the second alternator?
Usually yes — a properly-sized DC-DC (30–50A) on the OEM alternator handles most overland loads. The alternator audit tool warns if you’re pushing the OEM spec.
What battery should I run in -30°C?
LiFePO4 with a heating pad + low-temp charge cutoff BMS, or AGM if your trips are short and you’re charging only on the road. PowerLab’s cold-weather reasoning shows both paths.
Is a winch compatible with my dual-battery setup?
Yes, but the winch should feed from the starting battery (never the house bank). PowerLab’s wiring tab separates them and sizes the fuses.
Design yours in the next 10 minutes
Free tier gets you load + battery + solar sizing for up to 3 designs. No credit card required. Upgrade when you need the Co-Pilot, live BMS monitoring (Victron live today), or permit-ready PDFs.
Start designing free