Charging problem.

2008 750 breva. Last time out the battery boiled dry, checked charging rate at 15/16 volts at tickover. Bought a new regulator/rectifier fitted it and I am still registering 15 volts at tickover. Anyone know what is wrong.
I am not a mechanic and my knowledge and practical skills are basic, please respond with this in mind.
As an example it took me six hours to fit the regulator !

If it were me on my old crap I’d probably investigate the alternator first as being the source so to speak. As you can tell though, I’m no expert either. Incidentally it takes me at least six hours to do anything and these days you could probably double it if you include time to work up the enthusiasm.
Roy Green from the Forest of Dean

I may be wrong but I seem to remember these type regulators need a good earth, they work by reducing alternator Volts which is otherwise too high. But as I say I’m only surmising.

Roy, Mike, thanks for your replies.
I could investigate the alternator, but I would have no idea what I was looking for,unless it was something simple like a broken wire but that would not seem to be the case here.
Six hours working up enthusiasm seems fairly quick to me!

Mike, do you mean the unit itself being earthed or one of the wires is an earth wire?


A regualator rectifier unit woudld normally have an earth wire, it’s alway good to make sure the casing is well earthed as well, usually through it’s mounting.

Thanks Don.