You have to make call, it’s urgent. And you see your cell phone battery has run out of charge. That’s very annoying. With no nearby cellphone charger you might feel like tearing hairs apart or kicking in your own rear badly. Don’t worry; many of us felt the same way several times in our life. But hold on. You can avoid the pity. With little effort you could build a solar powered mobile phone. The job is not much tricky and requires very few inexpensive resources. Once done you would only need to keep your mobile phone lying on open daylight and battery would start running again. With solar panel, installed on the back side of the phone, you won’t need to carry anything extra separately. So there is no chance of forgetting. Just carry the phone wherever you go. To know more scroll down:
Difficulty level: Moderate
Time required: 2 to 3 hours
Estimate Cost: Around ₤10
1. A mobile phone, preferably cheaper one like F3 from Motorola
2. A small solar panel with 4.5V capacity
3. A 1N5817 Schottky diode
4. Soldering machine
5. Aluminum tape
6. Epoxy and super glue
7. Drill machine
8. Enameled wires
1. First of all, you have to attach the solar panel on the back side of your phone. For better bonding you need to drill holes on the back cover. These holes would not only allow better fixing but also drain out extra adhesive through them, which you can wipe out later.
2. Once done with installation of solar panel, you have to place the diode. This would confirm steady one way flow of electricity and save solar panel from accidental discharge electricity flowing from phone battery. So diode is an inexpensive but very crucial part of your project. You have to place and connect it properly.
3. Trim a small part inside the frame of the phone, enough to house tiny diode with it two trimmed metal legs. Diode should be placed horizontal to the side frame.
4. Clearly remember cathode and anode sides as now you have to solder the wires and connect them to the battery charger terminal.
5. Keep wire connected with cathode separate from the wire connected with anode. This would eliminate chances of shorting.
6. Use aluminum tape for covering the wirings. Conductive aluminum tape would lower the risk of circuit breakage and shorting too.
7. Once done with connecting diode with internal lithium-ion charger, you need to connect solar panel circuit with the diode.
8. This internal wiring is a bit tricky as you need to hide everything inside the body and at the same time need to keep them safe from shorting. Here, you can apply your imaginations and make an individual way out.
9. Finally before closing the back cover test the circuit. Once tested properly, just close the back panel and switch the phone on.
Frequently asked questions
Q. Can I use other mobile phone models?
A. Yes, you can. However, after busting the back side of your phone and running circuitry inside, you would definitely loose warranty on the phone. So, avoid using expensive phones. Besides, solar panel would definitely obstruct backside camera. So you have to avoid those phones too with camera lens on the back cover.
Q. What size of solar panel should I choose?
A. Remember to match the size of the back cover of your phone with solar panel dimension and the panel should yield voltage not below 4.5V. Solar panel lying outside the phone body won’t be practical solution.
Q. How long I need to keep the phone on open daylight?
A. From phone to phone, charging time would differ. But, there is a thumb rule and that is, 6 hours of sunlight could run the battery for near 18 hours. But that’s just a thumb rule. For exact calculation, you need to do a bit calculation on standby power consumption of your phone and capacity of the battery.
1. You can do with super glue but epoxy works well and it is kind of permanent solution.
2. Clean out the gloss from the back cover with sand paper when gluing the solar panel. Adhesive would work better.
Things to watch out for
1. Extra cover of solar panel on the back side could obstruct signal reception by the internal antenna. So, you could face difficulties in using the phone within enclosed compound.
2. be extra careful when using soldering machine.
3. Clearly mark positive and negative terminal of internal charger and connect cathode and anode accordingly. Any exception, even unintentional, would spoil the internal electronics.