My partner wanted an additional battery for her Trek Domane electric-assist gravel bike. She bought the Hyena range extender battery that mounts to the water bottle cage bosses on the seat tube. But the bike's small frame size made it inconvenient to attach and remove the plug of the charging cable at the bottom of the battery. I looked at a commercial cage shifter but it's designed for water bottles and is too narrow to adequately support the heavy battery. So I made this adapter to shift the mounting holes for the battery mounting plate up by 15 mm. This distance was limited by the available clearance between the top of the battery and the underside of the bike's top tube but it provides enough space for inserting and removing the plug without having to detach the battery from the mounting plate. I printed the adapter using PETG and 50% infill.