Build a small portable solar panel to charge two AA rechargeable batteries in a day or two. Make any battery using the battery- Solar power equipment. Build a small portable solar panel to charge two AA rechargeable batteries in a day or two. Make any battery using the battery- Solar power equipment. Or use the panel to power the small DC electronics directly. The panel consists of eight 1 \"x 3\" solar cells, which are connected in series with barrier diodes mounted on the board and protected by transparent plastic. In this configuration, the panel provides about 250 mA at 4 volts, which will charge two batteries in a day or two depending on weather and battery capacity. For example, other solar cell configurations can provide more or less power to charge directly to 3. 6 volt cell phone battery or provide faster charging for AA battery. There\'s a lot of off- There are ready-made small solar panels on the Web, but build one yourself and have the flexibility to configure it to provide the voltage and current needed for the project. And it could be cheaper. My initial goal was to charge the phone using several small 1 \"x3\" solar cells I purchased a year ago. For my first panel, I connected nine units in series and installed them very simply on a board without a lid. This generated enough power to charge my phone directly. However, it has several shortcomings. First of all, I find that I need to charge my phone when the sun is not bright. Second, when I want to answer the phone, when I am inside, the phone often charges outside. Third, the cells are dirty and one is broken. Finally, because the circuit can run in any direction ( Non-blocking diode) , When there is no light, the cell phone battery will discharge to the panel. My way to solve these problems is to add flexibility by charging two AA batteries instead of the phone, and put the charged battery into Minty Boost to charge the phone. To better protect the batteries, I glued them to the back panel and covered them with transparent plastic sheets. Blocking diodes prevent battery discharge. The inspiration for installing the battery comes from other power. ComI can\'t find any other resources on the Internet that contain the details of creating their own solar panels, but there must be something. Before designing the panel, it would be helpful to know some basic principles about solar cells. All common solar cells, like the multi-Crystal batteries used in this manual, produce 0. 5 volts or so. That is, there is a 0 before and after. 5 V difference. The size of the battery determines the number of amps. A full-sized cell (6\"x6\") It can produce three amps according to its design, but the smaller battery may produce only 250 amps or less. To increase the voltage of the panel, connect the battery in series. To increase the number of amps, connect the battery in parallel. Eight solar cells ( I bought polycrystal cells online. Try Silicon Solar, Plastecs, eBay, or Google search, for example. ) Small size wiireribbon line ( Flat wires commonly used to connect solar cells to each other. I purchased cells that have been connected to the ribbon in front of each cell. You can connect with normal wires, but the flat straps are unlikely to cause the battery to break when installed. )clear plastic ( I use 0 plastic. 1 inch thick) Four to six wooden screed battery stand for two AA batterieswood, about 1/2 thick panel paint adhesive ( I used an adhesive/sealant for the bathroom, but the silicon should work properly) Soldersoldering ironwire knife/stripperdrillpaint brushsawCut the correct size of a whole solid wood plate, responsible for solar cells. I arranged the solar cells in two columns and four batteries ( Make the panel more square than the rectangle). This covers 6 1/2 \"x4\", in addition, I also added the wiring space and fixed the cover to the back, with a final size of 8 \"x 5 1/2\" for the wood backing \". Sand and paint wood. Put it aside to dry. All cells will be connected in series, that is, the front of each cell will be connected in series to the back of the next cell. Cut the ribbon into ten pieces about 1/2 long. Weld eight of them to the front of all eight batteries, allowing about half of them to reach out to each battery. ( The extra will be welded to the back of the next unit in the series. ) I found it easiest to first apply welding on half of each ribbon and let them cool, then put the welded ribbon part on top of the battery, weld it without adding more welding. Apply the solder to the top of each ribbon outside the extended battery. This solder will be used to connect to the back of the battery. Flip the cells carefully and arrange them in two columns of four cells. Position them so that they are close to each other, but do not touch ( Maybe a quarter. inch apart-- They expand at high temperatures). Bend the ribbon so that the welded part touches the back of the battery. Weld the ribbon on the back. Weld the remaining two ribbons to the two unwelded backs. Remember to apply the solder to the ribbon first. You should now have two groups of four cells with ribbons in front and back of each group. When the two groups of cells are upside down, put them together with each other the way you want them to be on the finish panel. Make sure that the ends of each group have ribbons attached to the opposite side of the unit. That is, the cell at the top of one column should connect its top ribbon to the front, while the top cell of the other column should connect its top ribbon to the back. Now that they are in place, cut a wire at the right length to connect the two top straps. Weld it to the tape. You may need to flip these cells carefully and do a continuity test. In the case of plenty of sunlight, they produce about 4 volts and 250 mA. Voltage and amperage are reduced in indoor light. Do any fixes now and reverse the cells again. Using blank paper, create a template by tracking the backing profile built in step 6 to the paper. The profile will be used to position the cell to the back. Carefully slide the template under the solar cell and place it in the profile as you want them to be installed on the back. Leave enough space on all sides to connect the transparent plastic cover and the two wires welded to the battery. Apply a dab adhesive of approximately nickel size on the back of each battery. You want enough to stick the cells to the backing, but not enough to spray out from the side, and not enough that the cells will eventually sit high from the backing --- They need to be close to the backing to fit well under the plastic cover. Keep the backing above the cell and use the template profile as a guide to gently press the backing onto the cell. Cells are in danger of breaking on the steps, so be gentle but firm. Pull up the backup and want the battery to stick to it and flip it over. You can do some repositioning to make sure that each cell is pressed well on the back. Cut out two wires about 6 inch in length. Weld a piece to the ribbon attached to the back of the bottom battery so that the Wire points to the right, where it will exit the panel. This is ground connection. Weld the diode to the remaining ribbon. The orientation of the diode is important-- Make sure it does not block the current. If so, pour it over. Connect the second wire to the diode and let it move to the right. Cut a piece of transparent plastic into the size of the backing. Cut four pieces of plastic to form a frame around the cells. These pieces should be thick enough that when they are arranged around the cells, the lid will not touch any cells once the plastic cover is placed on the lid. Make sure there is a small opening in the lower right corner of the frame so that there is room for the two connecting lines to exit the panel. Attach the frame piece along the entire length of each piece to the backing with a small amount of adhesive. Place the connection line in the exit frame. Once the four wires are fixed, place the plastic cover on the panel and drill holes for the wood screws. Make the holes in the plastic a little larger than the screws to prevent the screws from creating pressure on the plastic. Screw the panel in place and seal any joints, especially where the connector wires are sticking out. The adhesive or silicon on both sides should keep moisture well. Weld the battery bracket wire to the connector wire of the solar panel to ensure the correct connection of the positive and negative poles. To protect the battery holder from rain, put it into a plastic container, like a cheap Tupperware container, with a hole on the side of the wire. Solar panel complete-- Put it in the sun and charge your battery. I estimate that the power of the solar panel is 250 mA and it takes 10- 12 hours charge my 1800 mA/hour battery. While diodes prevent the battery from discharging into the solar panel, there is no protection against overcharging, so don\'t leave the battery outside for too long. In addition, the panel may not be able to rain. Even if it\'s sealed, I\'ll take mine in if it looks like it\'s going to rain. Solar panels have been very useful to me for the past month. The AA battery is charged within a day or two and the plastic case has so far protected the battery. Minty Boost can charge my phone with AA battery. ( I had to splice my phone connector to a USB connector. ) By unscrewing the lid, I was even able to parse the diode to the connector wire after it was released in some way. I also made a jumper with a paper clip to allow me to charge only one battery. ( The jumper is installed in the second battery position in the battery holder. ) There was a time when I wanted to improve the solar panel by adding a logic circuit to prevent the battery from overcharging. Also, I would really like to leave the panel permanently outside and put the battery inside, which would be convenient to protect the battery from extreme temperatures. So far, when the weather is good, I \'ve been taking panels and batteries outside and bringing them in when the weather is bad. Just do a bit of work, this panel design can charge 12- Volt battery or external laptop battery.