Wes Siler wanted a big refrigerator-freezer for his truck camping trips. And we mean big. As in 70 liters.

"Not only does it allow me to take nice food off-grid for longer periods," he writes for Outside magazine this month, "but also bring along the raw meat that I feed my three large dogs daily and keep anything I catch during my hunting and fishing trips as fresh as possible."

So he attached a couple of 100-watt solar panels to the roof of the camper body on his Ford Ranger pickup. The solar array charges a portable lithium battery that powers the fridge and other accessories, even when the engine isn't running.

"I installed this solar-power setup specifically to enable a very large fridge-freezer to keep ice frozen indefinitely," he writes. He uses the ice to chill a massive 220-liter cooler.

Photo by Travis Hess/Outside

Siler describes his solar solution as "surprisingly cheap, extremely effective, and easy to install." Total cost was about $1,500.

He tested it by driving his truck around town normally for a week in August, running normal errands and making no effort to park in direct sunlight. Otherwise, the truck sat in his driveway (shaded for half the day).

"The battery would typically charge to over 90% capacity while running that freezer in its hardest-possible-duty cycle, then discharge to around 10% overnight—not a huge margin for error but it worked."

The solar system runs separately from the truck's main electrical system, so the fridge and other accessories don't run down the battery needed to start the engine.

"I've obtained a significant added luxury without sacrificing any of my stock truck's reliability," Siler writes, "and at a cost that would have been unbelievable just a handful of years ago.

Also, "I'll always have a cold beer ready at the end of a hard day."