Battery Stopper seat tube clamp
Aluminium piece that clamps around the seat tube of the e-bike, just below the seat post clamp. Although this piece looks like a seat post clamp, it is not. It goes underneath it, around the frame tube itself.
Its function is to limit the movement of the vertical battery pack on older eZee bikes, to preserve the life of the battery terminals.
Since 2016 it has not been necessary except with the tall battery pack (eg 28Ah or 34Ah) and even then only in some cases.