The NiCd cells in my Norelco T770 beard trimmer finally gave out, for the obvious reason:
They’re rated at 600 mA·h, as are the much shorter 2/3 AA NiMH cells I also used for those phone packs:
That’s a wrap of Kapton tape around the cells, plus a block of closed-cell foam to fill the cell holder. It’s not a high-stress environment, so this hack-job repair should work fine.
The trimmer’s charge / discharge cycle remains hostile to NiMH cells and I don’t expect a great lifetime from the new cells, either…