Hello,
I recently bought a new battery for my Roomba 650. After that it no longer charges on the dock. I can attach the charging cable directly to the Roomba and it charges but doesn’t charge on the dock. If I press the ‘Dock’ button it finds the dock correctly and then wiggles trying to find the socket but then undocks itself and goes off. Seems like it is unable to recognize that the dock charge.
Sorry, my English is not very good (thanks Google Translator) have you tried to clean the charge connectors ?. Clean them with alcohol. Sometimes they get dirty and in that case they do not make good contact.