Replace dead cells with fresh cells in fifteen tiny electronics. It will require soldering.

Task list for my project: 1. Desolder wires from the depleted batteries. 2. Solder in new batteries. 3. Leave a little extra wire at both ends for easer disassembly next time it's needed, to avoid the ends breaking away from their solder points. 4. Do not desolder any wires from the small round sensor with tiny LED. 5. Avoid the wires breaking free from the end with the threads. If it happens, remember how they're soldered, so they can be replaced. 6. Clean all soldering areas, especially the end with the threads. 7. Insert into the provided sleeves, with the writing on the tube placed at the end with the sensor, not at the end with threaded cap. 8. Test each one to ensure the LED end lights up, and they provide good vapor (this must be done by drawing air from the mouthpiece covering the atomizer that screws onto the end with the threads.) 9. Make sure each unit charges (the LED on the charger will be red until charging is completed, then it turns green when finished.) The LED end of the device also turns red while charging, (and it turns off when charging is completed.) *There are two black wires; one that runs from the battery to the tiny circuit board, and the other that runs from the battery to the end with the threads. There is one red wire that runs from the battery to the tiny circuit board. There is one yellow wire that runs from the tiny circuit board to the opposite end to attach to the cap with the threads. *I will send all parts needed for testing, but I will also need them back. *I will not send the small caps that go onto the end of the battery sleeves, as those aren't necessary for testing. They just serve as an LED cover to give them more of a realistic look. I'd rather put those on myself upon getting the devices back. I have two units I will send partially assembled, so you'll have a visual of how they get put back together, but they will also need a battery change. I have disassembled all the other ones, so you don't have to do it.