>>2948885
The FET blew up from spiritio effect, swapped it for a Darlington, still failed, and my cathode half eroded because not enough current was flowing. Tried to refactor it with high-side transistors, it worked but the pass transistors and linear regulators got too hot with the increased current. Tried to fix it with rudimentary heat-sinks and another lower voltage rail from the transformer (still need the higher voltage for a solenoid actuator), still got warm, and the voltage dipped low enough that things started not working for some strange reason. The backup battery charger would just turn on and off periodically. All the refitting of the same vero-board made it a mess of wires.

I give up, I’m buying some CC/CV buck converters (one for charging the battery and another for electrochemistry), and a 2S balance BMS with another 3.2V cell so I have the voltage headroom to power them. Maybe I should pick one of those buck modules with the screen and buttons built in. Either way I’ll drive the buck converters significantly below their maximum power capability, hopefully they’re reliable enough. Then I can add a buzzer that makes noise in case the battery charging or electrolysis fails, or in case the shorting of the electrodes isn’t fixed with a solenoid pulse. Might be a good job for an ATtiny13.