started 23rd July 2021
I once won an auction for a Canon Power Shot SD750 on ebay and it came without a battery charger. I bought one, and what I got was a fake CB-2LVE. It generated anxiety, from needing a "death o' dapter" for its non-UK plug, via the presence of AC mains on a dubious PCB (marked PXH662-A) to what it might be doing to the battery. But it did work, until the day it didn't. I got off lightly, it just stopped working without any smoke.
Looking on the web I found someone using a TP4056 battery charger break out board for the same Canon NB-4L battery. I could have 3D printed that design, but what appealed was to 3D print a piece of plastic that would allow a TP4056 board to fit in the existing charger case - I got to use the battery connector.
There is an excellent article about the TP4056 here and a video on repairing a genuine Canon charger here.
In the original charger the black plastic containing the mains socket, which slots into the case, is used to support the PCB. I designed a 3D print which holds the TP4056 board in a similar way. Another print, which I glued in, is a block that holds a couple of 3 mm LEDs over the translucent plastic in the case.
The TP4056 board came with a resistor to give a charge current of 1 A (it is the one marked 122 i.e. 1.2 KΩ), I replaced it with a 5.1 KΩ resistor giving a charge current of 250 mA). The two on board LEDs were removed and wires run from their former locations to the new LEDs in the printed block.
