^Hmmm. I never remember getting directions with my original VR715, so it is quite possible that I connected it before it had a ground (but I always disconnect the battery before doing any such work, so I'm not sure it would matter). This time around, I'm going to make absolutely sure that I do it right. This VR does have rubber mounts, so it uses a ground wire.
I never had any lost connection, battery or overcharging issues.