How much solar does a teardrop or off-road trailer need?

Answered by RV Parts Giant · Upland, CA · October 11, 2026

Short answer: A teardrop or off-road trailer running only a 12V compressor fridge plus lights, pump and phone charging uses about 550Wh a day. For three days off-grid our calculator sizes that at 150W of solar and a 200Ah LiFePO4 battery with a SmartSolar MPPT 75/15 or 100/20, and no inverter.

Small trailers carry less, but they are usually taken further from a plug and for longer. The calculator's off-road / teardrop preset reflects that: fewer loads, more days.

What the preset assumes

Load	Amp-hours a day (12V)
Lights, water pump, phone charging, vent fans	18
12V compressor fridge	25
Total	43Ah, about 550Wh

Three days between recharges, about five peak sun hours, parked at camp. The math uses a 12V bank, 85% usable LiFePO4 capacity and 75% real-world solar harvest.

The result

Battery: 200Ah. Three days at 43Ah is 129Ah, and 85% of 200Ah covers it.
Solar: 150W. One 200W panel covers it.
Controller: SmartSolar MPPT 75/15 or 100/20.
Inverter: none. Everything here is 12V, so there is no inverter idle draw eating into the bank.

What changes the answer

Change	Daily use	Solar	Battery
Preset as above	550Wh	150W	200Ah
Two days instead of three	550Wh	150W	150Ah
Cloudy or forest camp (about 3 peak hours)	550Wh	250W	200Ah
Diesel heater or furnace running at night	678Wh	200W	200Ah
About an hour of driving a day, with a 30A DC-DC	550Wh	100W	200Ah

Shade is the one to plan for off-road. If you camp under trees, set the sun to the cloudy option (about three peak hours): the array goes to 250W and the controller up to a SmartSolar MPPT 100/30. A portable panel parked in the sun while the trailer sits in shade is the other way to get there.

A furnace or diesel heater running at night counts as 10Ah in the calculator, which is 128Wh a day and the step from 150W to 200W.

Building it in, or not

The Renogy 200W 12V Starter Kit covers the 150W array. If you would rather not wire the trailer, the calculator's portable match for three days is the Jackery Explorer 2000 v2: 2,042Wh against about 1.6kWh needed. Already own a 12V battery? The ArkPak DC20 adds a 20A DC-DC charger, MPPT and a 1000W inverter around it (battery not included). On a wired build, a SmartShunt shows what the fridge really draws.

Run your own numbers in our RV solar & battery calculator. It opens with the off-road / teardrop preset filled in.