|RadioShack 6V solar panel|
Typical power output : 1.5WBecause of the relatively small output current the solar panel can produce, it is recommended that this charger to be used to charge a power bank or a shut-down smartphone. If the charger is used to charge a power-up smartphone, the net current used for charging might not enough to charge the battery because the smartphone will consume most the the charging current.
Typical voltage output : 6V - 5%
Typical current output : 250mA -5%
Overall size : 129.8mm x 84.8mm x 3.2mm
[25 NOV 2013]
I conducted a simple experiment on how much the solar panel power will produce to fill up my 2600mAH power bank. For a full day of Sun, it fills up about a quarter of the power bank. I guess that's why commercial solar charger for outdoor use include about four solar panels to get the right amount of power to be useful at the outdoors.
Bill of materials
- 6V RadioShack solar panel
- 1N4937 diode
- Wire connectors
- Old USB extension cable
- A short bypass wire
Prepare the blocking diodeBecause I am so lazy to dig out my soldering equipment for such a simple project, I decided to use screwed wire connectors. This is how it looks like:
|Blocking diode to prevent the current back flow to solar panel|
Prepare the solar panel housingSince RadioShack packed the solar panel with a nice plastic housing, I decided to use it as my solar panel housing and thus provided me with weather proof feature (some what).
- Wash the housing clean.
- Drill a small hole enough for a USB cable to go through at the bottom.
|Hole at the bottom for the USB female connector cable|
Prepare the USB female connectorFor the USB female connector, I used my old USB extension cable.
- Cut the USB extension cable into two and use the female connector part of it.
- Strip the cable and to pull out the wires for power connection.
|USB extension cable cut into two|
|Stripped wires for connection with the solar panel|
Assemble the solar panel USB charger
- Get the USB cable through the hole at the housing.
- Connect the red wires to the diode. Note the direction of the diode. The correct current direction is from solar panel to USB cable.
- Connect the black wires to the bypass.
- Put the solar panel and the description cardboard back into the housing.
|USB cable going through the bottom hole|
|Solar panel and the USB cable connected to the solar panel with a blocking diode and properly palced back into it's original housing|
|The original description cardboard placed back into the housing|
- The housing is perfect for my use case. With a carabiner, I can hang it on my backpack or windows or anywhere there are sun light.
- It's some what weather proof to drops and little bit of rain.
- The original housing looks great too.
|Completed solar panel USB charger|
References, Sources and Credits: