Recently I have done the 20w solar charge controller well and I still need to finish the power output. Currently, I can charge items like battery pack and mobile phone via 5v usb. To charge 3. The 7v 18650 battery voltage must be reduced from 5 v. Simple matters of TP4056 lithium battery charging module. 3. The 7v 18650 rechargeable battery can be purchased through a variety of distributors, and can also be recycled from discarded laptop batteries. When the battery in the laptop can no longer keep the laptop charging normally, the fault usually lies only in the discovery of 18650 sets or two sets of batteries bundled together to provide the required voltage. They can recycle and use these very useful batteries instead of discarding themg. flashlights ( Either diy or online) Arduino or other electronic items. This explanation explains a simple and cheap way to charge solar energy. 7v 18650 battery. Read On. . . . . In the image above, I have included an earlier version of this project on the right. In this earlier version, I installed the solar charging module and battery seat on a thick piece of plastic. This time, we will omit the plastic pieces and stick the solar charging module directly to the back of the battery holder: 3. 7v 18650 battery stand with 6 \"leads from ebay, about 50 cents to $1 If I could find a more \"solid\" battery stand, I would spend more money. These are very fragile, but do the job well. The TP4056 mini USB lithium battery charging board 1A 5v is about $1 more. If you purchase multiple usb to mini or micro usb cables, it depends on the tool of the purchased TP4056 charging board: the Thermal glue gun connects the TP4056 charging board to the back of the battery rack and keeps the wires in the information related to buying from the Chinese market and buying locally. When buying from the Chinese market, very good bargains are available. In some cases, how do they deliver to my door at no more than postage I can\'t understand watering the electronics! As a newbie to electronics, I did make a lot of stupid mistakes, turning brand new parts into a bunch of useless stinks! Even those of us with limited income can make a mistake here & buy there when the parts are cheap. There are many reasons why we have to buy locally. Of course, it may be a little more expensive to compare local prices. But with this, there are benefits. Better packaging, faster delivery, understandable specifications and instructions, better quality and product assurance & what about the work of people involved in manufacturing and selling? I hardly mentioned this topic because the problem is too big to get into here. Something to Remember when buying parts. There are very few welding in this project. The positive and negative poles on the battery stand need to be welded to the TP4056 after trimming a few inches from the end of the wire. After welding the TP4056 module to the battery bracket, heat bonding is performed. Then add more hot glue to better stick the module to the battery rack & keep the wires firmly in place. Please pay attention to the safe work of the heat surface. This is especially true for hot glue because it looks cool when touching, in fact it can cause severe burns to your fingertips! Make the glue time hard. It doesn\'t take a long time. Connect the mini usb cable and slip bar to the battery that needs to be charged. This project is about solar charging. 7 v 18650 li- Ion rechargeable battery, usb cable can be plugged anywhere in 5 V ( & 500 mA to 1 amp)are available - Whether it\'s a laptop, pc, power strip, battery pack, etc. Thank you for taking the time to read my instructions. Let me know if you find any errors and/or any improvements you have made. Come on! That\'s it. Because they are cheap, it won\'t hurt to do one or two or three. I have entered my instructions in MAKE ENERGY: A US- Innovation Challenge in Mexico Thank you very much for your vote on my project! Please vote at the top of this page if you wish! Thanks! A couple found the same circuit board on ebay, but about 50 cents per piece of circuit protection, but you need to buy 5 pieces and I would say it\'s a big deal! If some of you like the project but don\'t have the time or interest to put it together, I found out on ebay that someone has put together a version of this project & is selling us 5 bucks here I found other people posting. Ion battery charger using tp4056 on the Internet. Prove that this is a simple functional design worth repeating! To be honest, they posted it before me!