Powering Our Paddle With a $250 Voltaic Solar Box | Mississippi Source to Sea 2023

  • Updated: August 30, 2023
  • Post By: Matthew Hengst


The piece of gear which provoked the most comments during our extended journey down the Mississippi was our solar box. I assembled it from pieces sold by a company called Voltaic with the goal of having something we could just set out on the boat and have it generate power without us having to micromanage it when the weather got bad.

I have always loved the idea of solar but at least so far I've found that the state of technology doesn't really lend itself to being usable on long distance hikes. When you're getting started early and hiking until evening you can't really set a panel out for any length of time during the effective hours of sunlight and putting it on the pack while hiking usually doesn't work real well due to the fact you invariably end up partially shading the panel. And then there's the fact that lighter panels tend to be fragile and even the few folks that I've met who have made it work seem to have had to replace them multiple times. And I'm harder on my gear in general than all those fine folks.


But when we started planning for our Mississippi Source to Sea paddle one of our goals was to avoid the constant need to go into town to charge our hiking batteries. Because it's one thing getting a ride into a hotel when all you have is a backpack and quite another when you have to deal with a 17 ft canoe loaded down with gear. And in fact we only slept in town 6 times over 75 days and when we did indulge it was never driven by the fact we were lower on power.

Since after the headwaters the river is quite wide we didn't have to worry about overhead trees shading the box. And I worked around the fragility issues by using a hard panel vs anything bendable or foldable.


And this was the end result which successfully saw us through 10 weeks and 2,460 miles despite all the rain, wind, boat wake, and heat waves. 

How I built the Voltaic box

All pieces were ordered from the Voltaic website. Total cost was around $250 with tax which I paid myself. I ended up buying from Voltaic after coming across their online store while researching various types of solar kits.




I then threw in a lightning to USB A cable I had sitting around since the V75 batteries only have a USB A output and I had a completely self contained system.


With the case conveniently pre drilled with a waterproof port to connect the outside panel with the batteries inside it was just a matter of plugging things in and then figuring out how to attach the panel to the top of the box. I used some heavy duty velcro tape which had the advantage of being theoretically removable though in practice I've avoided this since it felt like it might crack the panel.

I liked this solution since we could just set the box out anywhere and not have to worry about panel positioning or putting it away when it rained. And it was easier to manage since it was just a single piece.


I started with a single V75 battery when we did our warm up paddle of the Suwannee and afterwards decided to add a second. This was to give me extra capacity if we ended up with multiple days of cloudy weather.

How we used it

Since we make daily videos documenting our adventures our power needs tend to be a bit higher than your average hiker or paddler. I'm also an audiobook addict usually listening for 7+ hours a day and we use our phones heavily for navigation. Add on to this we were often trying to upload videos to YouTube via cell tower.

Our general routine was to take one of the batteries into the tent with us at night to charge my phone and other electronics while we left the often sandy box outside. In the morning we would plug in whichever battery was currently lower and set it on top of the Bill bag right in front of the back paddler so they could keep an eye on it. We never really worried about positioning it vs the sun and because of the weight of the two batteries and the case we never had an issue with it sliding around when we were fighting heavy winds or getting thrown by waves.

I found the box did well enough and that with the two batteries I always had enough power though I was usually running down over time. Though do keep in mind I wasn't near as disciplined on my power use since we had a renewable source along.

It was enough along with my backup hiking battery to easily get me maybe two weeks between towns without any serious concern about running out. And when we did go into town we would top off the V75 batteries using my hiking wall charger to the USB C input port on the top.


There were only two real pain points. The first was the usb mini connector didn't seat super securely so we were often paranoid about verifying that the battery was charging after it had been moved around. That just required popping the box open and checking the lights on the battery were blinking when the panel was exposed to the sun. We usually did this at least once a day once the sun was up.

The other issue had to do with the port added to the nanuk case.


Because it came out the bottom and stuck out so far we had to constantly be on guard so that we didn't bang the wire and break it or cause the port to leak. This included needing to pick the box up by the sides instead of the handle since doing the latter would bang the wire on the ground.

What I would do differently

I'd originally hoped that the box was going to be big enough for the panel to lay flat and not have any ends sticking out over the edge. It turned out the 909 box is a little too small and curved.


It worked fine but were I to do this again from scratch I'd probably find a bigger flatter waterproof case where the 9v panel wouldn't stick out at all. And then I would try to make the wire coming out protected somehow so we didn't have to constantly be on guard.

I might have wished for a slightly bigger panel but considering we carried this onto two airplane flights there were advantages to having it relatively small.

A note about other options out there

That there are a number of folding solar panels on the market that can generate significantly more power since they have more surface space. I did evaluate a few and even ordered a 36 watt BigBlue to try out around town and on the Suwannee warmup trip. 


While others have managed to use these successfully I personally didn't care for it to the point we didn't even bring it on the Mississippi as a backup. The panel is water resistant but the documentation warns you not to get it too wet which can be difficult with how quickly the weather would change on us and the risk of boat wake occasionally coming over our sides. Also I found I started to have some issues with some of the ports after about a week of everyday use.


We also found that positioning the folding panels in the boat was a pain and it was easy to accidentally end up partially shading one or both of the sides. This combined with the fact we had to watch it if the wind kicked up and put it away during major rain had us just deciding to use the power box after the first few days.

And in conclusion

We found the solar box both met our needs and satisfied out expectations and I fully intend to use it again for future long distance paddling trips. 

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