TEAfternoon: 858D EARNING ITS KEEPDumbass dwagon toasted the charge circuit in his beard trimmer last night by mixing up his chargers.
Took it apart and found it uses a TP4056 charge IC
(datasheet attached below), which I happened to have oodles of on Li-Ion BMS boards I keep as handy Lego-type building blocks. OVP/LVP on protection IC work as expected testing with CV/CC power supply and ballast resistor, and new TP4056 is showing charge status with current right at 300mA.
Now to monitor the unit through a few charge/discharge cycles and see if it behaves.
EDIT: Completed charging in aboot an hour with terminal voltage right at 4.2221V; STBY 4.0840V.
mnem