Powerbank 50Wh

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).

My measurements for the INR 18650-35E Cells from Samsung in this setup:
Load:
11570 mAh (5V)
11535 mAh (5V)
11404 mAh (5V)
11469 mAh (5V)

Unload:
8485 mAh (5V)
8578 mAh (5V)
8517 mAh (5V)
8558 mAh (5V)
8429 mAh (~5V)

The datasheet of the cells said: 3400-3500 mAh at 3,7V so in theory 50,3 to 51,8 Wh.

The everage load is ~57 Wh
The everage unload is ~42 Wh

The datasheet of the PCB said conversion should be >85%.

If you want more information about the cells, klick here

Battery positive connects with chip B+,battery negative connects with B-.Please notice that don't transposition,or it will cause great damage to the module.

To check the status of the powerbank you have 4 blue LED´s (I don´t like the 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).

The threads are modified for better fitting. In my case, it works perfect but you definitly need a coolerfan. 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).

The 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 their are some simple tricks to fix your problem.

Itemlist:
4x Samsung Li-Ionen Akku | SDI INR18650 35E | 3,7V 3500mAh or from Banggood (~ 20,- €)
1x Charger Board PCB JX-887Y (~ 2,50 €)
1x Battery Connection Sheet or from Banggood (~ 2,50€)
1x Top case
1x Bottom case
2x Screws
1x Button

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