Had the same Optimate and fused flying lead on 4 different BMWs, and it's worked perfectly. I just leave mine connected all the time I'm not riding it. For anyone who hasn't fitted one before there's a red positive post just forward of the battery umbehind the right hand cover which you can use to save having to take the battery out. Connect to that 1st, replace the red cover, then use the negative terminal on the battery for the black lead. Job done. GLWS