I have an industrial strength 12V charger. Initially it would not turn off on battery removal. Replaced the triac and now works 95% of the time but in some cases it still does not turn off.
The way it works: Controller triggers triac to supply charging power(from transformer). The controller senses the voltage from the battery to determine how to charge the battery(full charge, "trickle", etc...).
Either the controller is bad(not turning off the triac), the triac is bad, or the circuit used is not well designed for the application(and/or designed for a specific triac).
Again, what happens is when the cables to the battery are disconnected the controller stays on instead of turning off as normal(and again, does not happen most of the time).
Simply because of the sparking involved when removing the battery cables it is obviously inductive(obviously because of the transformer). I believe that a snubber is probably in order(not sure if the controller has one and/or is bad/weak).
Any other obvious possibilities that I'm overlooking?