Whether you hike, camp, or just drunkenly lie in the sun at Coachella, a solar backpack’s an outlet-free way to juice up your gear. But you might not have upwards of $200 lying around. If you ARE rich in time and patience, Treehugger’s got a tutorial via Instructables for wiring up your own solar bag.

DIY-solar-backpack-instructables
Kajnjaps

Here’s the gist of it: You attach four encapsulated two-volt/200-milliampere solar panels together, fusing their wires with a soldering iron (you have one of those, right?). When you end up with a positive and negative cable, you connect it to a battery box to charge four NiMH batteries. That part looks pretty tricky — please don’t electrocute yourself (or get into a soldering gun battle … that shit burns!).

Once you’ve got the unit of solar panels, the battery box to go inside your bag, and connectors to power your iPhone with the batteries, you’re ready to head outside. Easy peasy, right?

Or not. You could always get a little solar charger like the Solio ($65), the Poweradd ($46), or the Nomad ($80) if you aren’t technologically inclined. Hopefully in the future, solar panels will be increasingly integrated in apparel — and not just on bikinis, either!