Barebone DIY USB Battery Bank, li-ion 18650 ( fat AA )
Barebone DIY USB Battery Bank, li-ion 18650 ( fat AA )
Double 18650 battery box
Got this DIY battery bank off ebay.
These are very common on ebay.
They are probably factory surplus.
The cover has to be preyed open with a plastic tool.
I smoothed out the clips so that I can open it with fingernails.
It comes with battery springs and voltage booster ( to USB ).
It does not come with a battery, not for $1.99 USD.