I know this should be in Tech., but I could do with a swift answer..

Do I need to disconnect battery to charge it (don't really want ECU to reset, but one the other hand I don't want to fry it..!)

It's only for a top-up overnight, every month or so. Using a Ring smart charger 4, which comes with plug in ring connectors to allow easy connection/disconnection. Disconnecting would make it a bit more of a PITA.

Battery is an Odyssey PC680.

Cheers, J

 

You can leave it connected fine, chargers now days are much smarter than the old transformers and a couple of diodes things of the past.