Controller Discharging?

[rbscebu]

In between rides on my ebike, I disconnect the battery from the controller. I notice that the controller retains a charge after being disconnected. I can discharge the controller by sounding the bike's horn for a couple of seconds.

The question is, should I discharge the controller after disconnecting the battery or should I leave the controller with its internal charge?

 

[e-beach]

The reason your controller keeps a small charge is because one or more of the capacitors in your controller has kept a charge. There is most-likely a bleed resistor that over a period of time will discharge the controller. In any case it does no harm to the controller to leave the capacitors with the charge that goes away when you power your horn for a few moments.

Do you notice a spark when you reconnect your battery?

 

[dogman dan]

The controller will slowly discharge itself when you unplug it, if its connected to the rest of the bike and supplying 5v to the throttle, halls, etc. Takes a few min with no display, a few seconds if a display is being powered.

But one thing to know, if you power up a disconnected controller, it will hold its charge a long time. Meaning you short the wrong thing in there with a tool, and zappo. I found that out once just cutting both battery wires at the same time to put a connector on. Cooked a set of cutters.

Other than making it safe to work on, no reason whatsoever to try to discharge your controller when you unplug.

 

[rbscebu]

Thank you both for your guidance. Much appreciated.