Greybeard

Hi Folks,
I've got a 2000 SV650SY. For completeness (and to prove that I read the instructions) it has a Piper air filter, intiminators, KX10R rear shock, pointy inlet cams and an R6 throttle tube, but none of that will affect the question.
When I bought the bike the battery was distinctly dodgy. I replaced it and all was well until I took the bike out for a track day a couple of weeks back. The track day was fine, but the "new" battery wouldn't start the bike the next day, or after a full cycle on the optimiser.
A quick check revealed that it was charging at a nice 14.8V at 5000rpm but up to 18V at 8000rpm. In short it looks like the reg rec isn't doing it's thing and I've fried the battery.
I happen to have a nearly new Electrex one from an ST1100 in my shed, but the darn thing has seven wires on it.
I'm ok with the idea of a battery live and a live after the ignition switch, but unclear on the remaining one. Has anybody fitted a seven wire to a curvy, or found out that you can't?
I've found a few threads on reg rec in general but nothing addressing this problem.
Cheers