I needed a powerbank for some situatons, when i cannot charge my phone for a longer time. But i wanted to create my own, because everyone can buy, and i have a lot of remains of faulty devices at home. And recycling/reusing is always a good thing!
First, i thought that i have 2 batteries for my old phone, almost unused, but fake capacity of 2200mAh. Together, they are 2000, i thought, it will be enough.
Purchased a powerbank PCB from ebay, for $2. This is the one new stuff in it. Dual USB output, 2A charging, flashlight function.
Then i looked for a case, and found that a dead external HDD's case is perfect, the components exactly fit, and looked good. Soldered the two paralelly connected battery to the PCB, and glued into the housing. The original connector side of the case was removed, this is the place of the USB sockets now. I decided to cover this with a semi-transparent foil, from a dead PC PSU, so the flashlight is usable.
The PCB was fixed with two screws into the case.
The flashlight switch was at the bottom of PCB, so i decided to glue an appropriate length tube of a wall-plug on the PCB to side, so if i press the case bottom enough at the WD logo, the flashlight turns on. Otherwise, the top of case can be easily removed, and put back. The charge level indicator LED's are also at the bottom of PCB, so i made 4 tiny holes for them to the bottom of the case.
Putting it together was about an hour long, so it was an easy hobby project, and i got used some plastic and batteries which would be go in trash at others -and it was cheap. Works great, pushes up the phone from 0 to 60% .
Layout
With cover, but with uncovered front
With the front foil
