Hiya, fitted one of these gubbins last year, can't remember the brand got it from DS. Made up my own bracket to fit it where the old voltage control unit was, there was enough play in the wiring to allow this. Bracket was made from half of an old brass window hinge, cut and drilled to suit, no rust, no paint, and a good earth! Had to start bike on kickstarter, had only just made it home, meter was showing 15.65 volts which did not surprise me with a nearly flat battery. Have not checked it again since, head in sand attitude! Have had to add miniscule amounts of top-up fluid about 3 times since then. If it aint broke, don't fix it. Had a similar unit as a standard fitment on a Stiga mower, when that one went wrong it gave plenty of warning, smell from battery which was very hot, and a reading of 19.5 volts!!! So don't panic quite yet.
Regards, Mick.