DIY Solar Bicycle Trunk Bag

I am hoping to do a fair bit of bicycle touring this season. I wanted a method of keeping my electronic devices charged without having to carry around dozens of disposable batteries. I decided that a solar powered bicycle trunk bag would be ideal given my own touring configuration. Searching about the web found one such product, but that device was expensive and had a single small solar panel; I was skeptical as to how much energy could be generated. When I found Benjamin Morrison's Custom Solar Bike Panniers, I felt that I had stumbled upon a solution that I could modify for my own purposes.

From Voltaic Systems, I ordered three 1.5 Watt 6-Volt solar panels and a Mini USB Circuit Box Set. The nice folks at Voltaic were willing to also send along a used/damaged Voltaic Converter shell for me to use as spare parts.

I had a simple Trek Bicycle Trunk Bag available and ready to be converted. Just about any bicycle trunk bag whose top can be sewn through will do.

The first step was to begin disassembling the Voltaic Converter for parts. I used an X-Acto hobby knife to carefully cut the threads on the front section . . .

. . . until I had removed the solar panel holder section in its entirety.

After this picture was taken, I carefully cut away the zipper.

Next, I used the hobby knife and a pair of sharp scissors to separate each panel holder individually.

I also removed several other portions of the bag, just in case other fixtures might come in handy later. You never know.

I installed the solar panels into the panel holders and verified functionality.

The LED that came with the Voltaic USB Circuit Box lit up immediately, which allayed a great many of my fears.

I used a soldering iron to melt a small hole through the top of my trunk bag. It worked great, but my housemate is annoyed that I used his iron. I would suggest using a heated nail instead.

I threaded the solar panel's output cable through this hole . . .

. . . and carefully sewed the first panel directly to the top of the bicycle trunk bag. Note that I re-used the stitching holes on the solar panel holder. No reason to add extra holes in the material unless you need to!

In this version, I removed sections of the bag's upper padding with scissors, sewed sections of the panel to the bag and then replaced sections of padding. If I were to repeat this project I would omit this step and simply sew through the padding itself.

I decided to create side panels out of spare black cloth that matched my bicycle trunk bag.

I sewed a piece of 1/8" foam between two layers of fabric, punched a hole for the solar panel's output cable, and then carefully sewed the panel holder to the fabric.

Next, I sewed the side panels onto the trunk bag.

I used a lock stitch sewing awl for this portion, and sewed through the bag in the fabric right below the zipper.

I also melted two more holes through the back of the trunk bag so that I could feed the solar panel's output cords into the bag itself.

Finally, I constructed simple supports to hold the side panels horizontal to the ground.

The supports were made of plastic sewn inside channels of the same black fabric, and are held on with industrial strength velcro. When the supports are removed, the panels are held to the bicycle trunk bag's side by the same velcro mounting points.

The solar powered bicycle trunk bag mounts beautifully to my recumbent trike.

I'm looking forward to my next tour!