Error 30 remains. Used a Q-tip and alcohol and the battery snapping sound is gone.

error 30 started a week ago. I checked all connectors and used dielectric grease on them and on the battery connections. I was able to get the bike going by simply dis- / reconnecting connectors. It worked for 2 30 rides. Now a cannot get error 30 to stop. The snapping sound at the battery happens even when I disconnect the cable to the hub. Many thanks for reading, Mark