Last year my DuoClear 130 control panel wouldn’t keep it’s settings when turned off. The manual doesn’t mention what kind of battery the unit uses if it fails. Finally I took the control unit apart to find it contains a ML2032 cell (this is very much like the CR2032 but a rechargeable version.

I was able to order a replacement battery for a few bucks on Amazon. I soldered two wires to the board and taped the new battery in so it works like new.