In this instructable I'll show you how to build a detachable solar panel and battery charger for your backpack. This can power or charge all your gadgets (cell phone, mp3 player...) while on the road. HAMs can use it to power small QRP transmitters and receivers on a field day etc.
I was inspired by the excellent instructable "Rain or shine solar charger" by Blondietheblond, but wanted to avoid sewing, since I don't have a machine. So this is the result.
Step 1: Gather the stuff you'll need:
0) a backpack (duh):
Most backpacks have enough possibilities to attach stuff. Mine provided these ribbons on the back. No idea what they are supposed to be used for.
1) for the solar panel:
- 4 Encapsulated 2V/200mA solar panels (Velleman SOL4).
- Self adhesive pads for cable ties (3M Scotchlok Ab02).
- Nylon cable ties to fit the adhesive pads above.
- Velcro adjustable cable binders (Tesa 55236-00000, 12mmx20cm).
- Heat shrink tubing.
- Electric wire (capable of carying 0.5A is more than enough).
- Connector to go to the battery box.
2) for the charger/battery box:
Parts list for this is less critical, so improvise. There's an explanation with important details ahead.
- Small plastic project box.
- 4 AA-size NiMH batteries (GP 2700 series is ok, see further).
- Battery holder .
- Two 2-pin panel-mount connectors of some sort.
- Components (see further).
...and some tools:
- soldering iron.
- sharp knife.
- drill for making holes in the project box.