Yep. That is what i think to do if not get sram oe part anywhere. Some kind little battery or capacitor is in oe part because it works some time if you run bike battery empty.
I think trek must sell this part for customers if someone broke it. Does someone know trek partnumber to that part what goes in derailleurs battery slot?
Yes i know it works allmost every magnet but i mean some ready product. Looked some shimano disks with magnet but will it work out of box because i see there are different option on magnet location/dimensions.