How to build a solar-powered radio of your own

Who can deny the practicality as well as novelty of a solar powered radio? Beyond the usage of sustainable renewable energy, such a contraption can do its duty even in remote locations, be it on your weekend fishing trip or camping trip. After all there are places in the world where batteries are actually not available. So either you can pack a lot of batteries (which makes the trip unwieldy), or you can make your very own solar powered radio that actually accentuates upon its portability.

Solar Powered Radio Set

Such a type of battery powered radio generally runs on DC electrical current, and that is exactly what a solar panel supplies. So a portable radio can just as easily be conceived by a little bit of your precious time and some heartfelt dedication. Without further ado, let us check out the basic steps for contriving one.

Difficulty level

Moderate (Requires basic knowledge)

Time required

The project will actually take less than even 2 hours if the basic steps are taken correctly.

Resources required

1. A radio which is portable (2AA or 3AA battery type).

2. A single 4 or 4.5v 80 mA solar panel. It can be salvaged from a solar light.

3. Ideally a BAT43 Schottky diode, though a Silicone IN4001 can also be used.

4. Soldering iron, solder and a red and black cable with lengths of 6"

5. 2 or 3 NiMh rechargeable batteries

Estimated cost

Less than $5, without the cost of the radio itself (we can use the older ones lying around the house).

Instructions

1. The first step would always be to salvage the solar panel from the garden LEDs. We should make sure the panel has 8 strips (for provision of 4.5v 80 mA output). After that we have to carefully remove the plastic and metal rims and then strip off the panel (generally glued to the inner surface) from inside the light fitting with the help of a screwdriver.

2. The next step involves the checking of the positive and negative points (connections) of the batteries by removing the rear cover of the radio. After finding out the connections (we can use a multimeter), we have to solder the above mentioned 6" cables. The red wire has to be connected to the positive, while the black cable to the neutral. Now the rear cover can be fixed back, though now with a drilled hole for the wires to pass through.

3. This next step involves the soldering of a blocking diode with the positive terminal of the solar panel, to prevent any reverse current occurring from the battery pack. We can always check if we had made the right connection by utilizing a multimeter (in volts). The right connection will exhibit a bright light from the panel.

4. The last step is to fix the modified panel on to the body of the radio system, or even on top of it. We can do this by using components like double sided foam adhesive tape. Finally, we have to solder up the positive and negative wires from the radio to the solar panel, and use insulation tapes to cover up the joints.

Frequently asked questions

1. How to check the battery connections?

A. We have to definitely make sure that the multimeter doesn't exhibit negative value. If it does so, then we have to change the alignment to the correct way.

2. How to check the diode connections?

A. Once again we use the multimeter (in volts). The right connection will exhibit a bright light from the panel.

Quick tips

Make sure that the solar panel has 8 strips for adequate output of 4.5v 80 mA. And for the blocking diode, usage of BAT43 Schottky type diode is preferable because of its low voltage loss.

Things to watch out for

Initially the portable radio would have been a battery powered contraption. Thus the battery pack inside them can have a leakage problem, which can be corrosive in nature. So, we have to be more careful when removing such hazardous components from inside the radio.