A previous article already talked about how to make a solar panel out of old garden lights. Since the power of the solar cells used in them is not so large, a fairly large number of cells are required to create a medium power panel. After assembling the solar panel, the author still has several garden lamps, but for another solar panel they are not enough. Therefore, the author decided to make a charger based on solar cells used in garden lamps.
Materials that the author used to create a solar-powered charger:
1) a piece of plywood sheet
2) garden lights 4 pieces
3) Schottky diode
4) soldering iron and necessary consumables
5) rechargeable batteries AA or AAA.
Consider the main stages of the creation and assembly of this charger.
To begin with, the author calculated the approximate number of solar cells from the lamps based on their power and the power needed to power the batteries. As a result, to create a charger you need at least four garden lights.
After that, the author proceeded to disassemble the garden lamps in order to get solar elements from them. You can also use the available battery holders, but the board and LED in this design are not useful.
If you wish, you can gently separate the solar cells from the cover of the garden lamp, since the cells are coated with a special resin, they are strong enough and with the proper approach will remain intact. Then place these items in a plastic case. However, to carry out such a procedure is only necessary if you need a beautiful appearance of the product, otherwise the use of elements together with covers is permissible. The author did not add work to himself and simply attached four solar cells with covers to a sheet of plywood. After that, the author began to combine elements in one design.
Below is a diagram of the connection of the solar battery that will power the batteries:
As can be seen from the diagram, all the elements are connected in parallel. In order to prevent the batteries from being discharged through the solar cells in low light, the author installed a Schottky diode in the gap between the solar cells and the batteries. Thanks to this diode, the charger will accumulate energy in the sun, and successfully save it in the dark.
The result was such a charger of 4 solar cells from garden lamps that feed the batteries.