Powerbank 50Wh

thingiverse

A 50Wh Powerbank (4 cells parallel) case with LED Light, 2 USB-A Connections (out 1A & 2,1A) and 1 Micro-USB-B (in 1A).\r\n\r\nMy measurements for the INR 18650-35E Cells from Samsung in this setup:\r\n__Load:__\r\n11570 mAh (~5V)\r\n11535 mAh (~5V)\r\n11404 mAh (~5V)\r\n11469 mAh (~5V)\r\n\r\n__Unload:__\r\n8485 mAh (~5V)\r\n8578 mAh (~5V)\r\n8517 mAh (~5V)\r\n8558 mAh (~5V)\r\n8429 mAh (~5V)\r\n\r\nThe datasheet of the cells said 3400-3500 mAh at 3,7V so in theory __50,3 to 51,8 Wh__.\r\n\r\nThe average load is ~57 Wh\r\nThe average unload is ~42 Wh\r\n\r\nThe datasheet of the PCB said conversion should be >85%.\r\n\r\nIf you want more information about the cells, click here.\r\n\r\nBattery positive connects with chip B+, battery negative connects with B-. Please notice that don't transpose or it will cause __great damage to the module__.\r\n\r\nTo check the status of the powerbank you have 4 blue LED's (I don't like LCD PCB boards). The case at the LED's is very thin. If you use translucent filament, you can easily see the actual capacity (check the pictures).\r\n\r\nThe threads are modified for better fitting. In my case, it works perfect but you definitely need a cooler fan. I recommend to print the 2 screws together or reduce the nozzle temperature. If you print the button, I recommend to print at least 4 of them or reduce the nozzle temperature.\r\n\r\nThe only points for soldering are the 2 connections on the PCB. The cells are jammed between the connection sheet. If you have problems with the assembly, please write me. Maybe there are some simple tricks to fix your problem.\r\n\r\n__Itemlist:__\r\n4x Samsung Li-Ion Akku | SDI INR18650 35E | 3,7V 3500mAh from eBay or from Banggood (~20,- €)\r\n1x Charger Board PCB JX-887Y from eBay (~2,50 €)\r\n1x Battery Connection Sheet from eBay or from Banggood (~2,50€)\r\n1x Top case\r\n1x Bottom case\r\n2x Screws\r\n1x Button\r\n\r\nFeel free to use my affiliate links because I need a beer now. Cheers.