How to make a solar panel for your phone

An active lifestyle of modern man implies that leisure time , he mostly spends not a concrete jungle metropolis, and in the bosom of nature. But this very nature for some reason not ozabotilas power of our mobile favorites. Plug in the trees are absent, and hungry gadgets constantly asked to eat . Meanwhile, our generous ( especially these days ), and absolutely free supply of solar energy . We can only take advantage of this gift .
For several years, leading handset manufacturers with an enviable regularity produce a model with solar panels ( eg LG GD510 and Puma Phone) , and the number of chargers that can convert energy from the sun , is large enough - for every taste.
However, the " solar " phones in their characteristics are rather weak in technical terms model and use a small demand . Charger is a solar-powered - is the extra weight , volume and cost. The best compromise , in our view , would release the manufacturers battery cover or covers with solar cells . This option we offer to make yourself .

What will

To begin with one needs to buy back the phone and power connector. The cost of a suitable Chinese products will not exceed 50-100 rubles at an acceptable quality plastic. A major challenge at first glance, it may be searching for suitable size of solar cells .

Solar cells , as one of fotovoltnyh converters , there are several types : based on gallium arsenide (GaAs), silicon single crystal , polycrystalline silicon and amorphous silicon. The first type of elements used in space and the sale of practically does not occur , although it has the highest efficiency ( 40% ) and space costs. Among the most widely used silicon mono - and polycrystalline elements for decent efficiency ( 9-16 %) and mature fabrication technology. Of the minuses is worth noting the fragility of such batteries , expensive and the fact that they are influenced by rainfall. Amorphous solar cells are much cheaper to manufacture , resistant to external shocks , but have low efficiency (6-8% ), and the time of their work is limited to 5-6 years. Nevertheless, so far only on the basis of their manufacture flexible pipes, including in the form of films .

When choosing a solar battery should take into account two things: size of cells and the desired voltage. Single element provides approximately 0.5 volts at maximum coverage - and, consequently, their need at least 10. We do specifically omit a question with current, generated by elements of various sizes . Important for us to fit a solar panel on the limited surface and output a desired voltage .
When assembling a battery of individual cells based on monocrystalline silicon can be difficult when soldering . The fact that silicon conducts heat well and strongly oxidized during heating . Therefore , in the absence of advanced soldering skills it is desirable to draw attention to the finished solar cell modules .

Frankly, weld themselves normal battery of miniature ( 15h6 mm ) monocrystalline modules author of the article failed . The design turned brittle and rough surface. This is purely a commercial version , and repeat it at home is not worth it. However, the battery provides sufficient energy level , and even greater than that of an option that we used below.

The shops of electronic components can be seen as separate elements , and has already collected in the battery modules . The ideal would be a module of 10 single-crystal elements with an output voltage of 5 V and a suitable size to the phone. Plus there is also the fact that the elements already soldered and covered with transparent plastic for protection from the external environment .
Buy a battery can be in one of the many Chinese online stores.
It is also possible that it would be easier and cheaper to get solar cells from Chinese calculators with solar powered or LED garden lights .
In the calculators are used mainly amorphous solar cells, where a layer of a semiconductor caused by a thin glass plate. However, the output voltage of these modules is seldom more than 1,5 - and hence their need at least 4 units with serial connection.

Assembly

We have chosen a more practical alternative to the battery of the LED flashlight keychain - cost 50 rubles .
In the bright light solar module confidently gave 5,5 B, and the two connected in parallel generated short-circuit current of about 200 mA.
Of course, the load current strength will be significantly lower. It is worth noting that, other things being equal monocrystalline elements generate a higher current. Welded together in parallel a pair of modules are placed on the cover of the phone with bilateral adhesive tape and fluster power connector , observing polarity.
In addition to the positive terminal of the battery must Soldered diode . It will serve as a valve , not allowing the battery discharges through the solar battery . Diode , by the way, you can vypayat the board flashlight .
For convenience and ergonomics , we reviewed the standard plug and left only the core of contacts . Maybe for another model phone, you can come up with different and more elegant solution.
To design was more durable , you can fill with solar cells on the ends with hot .

Findings

Thus we have an additional power supply to the phone . Enough to turn the device back side to the sun or a bright lamp, a turn on charging mode . Unfortunately, our home-made power supply can not provide a full charging current to the battery and will serve as makeup , slightly prolonging battery life . It is a little - depends on the area of batteries and extravagance of the phone . At least the battery on the Sony Ericsson G500 worked on a couple of hours more than without the " solar cover . What can be considered satisfactory result.
More effective would be battery powered directly from a solar module , bypassing the control circuit the phone . But this solution may lead to failure of a battery and phone.