Hi Guys, I have decided my battery is dead after it failed to start my bike for two days in a row, even though it had been on an optimate 4 for 24 hours.

With the ignition off, no optimate, I measured 12.87V
When cranking the bike this dropped to 7.somethingV
About thirty seconds after the failed attempt the battery read 12.05V

=

DEAD!!!!

So I am about to buy a new one, and I hope I don't annoy anyone asking ("Question asked 101 times now! no worries" quoted from Capt from one of the many old threads I searched through lol) which battery am I after?

In a few threads Capt linkd to this one: http://cgi.ebay.co.uk/Yamaha-XT660-R-04-MF-Gel-Battery-CT9B-4_W0QQitemZ140301022401QQcmdZViewItemQQptZUK_Motor cycle_Parts?hash=item140301022401&_trksid=p3286.c0 .m14&_trkparms=72%3A1683|66%3A2|65%3A12|39%3A1|240 %3A1318

which is the CT9B-4,

Whereas in another thread Kev said " Battery type GT9B-4/GS"

The G type is the one my current battery is, also that is the one listed in the Yamaha Parts Catalogue on here.

The C is cheaper and recommended by Capt, just wanted to check I would be ok getting this one instead of the G, I'm guessing it was just a slight revision of the battery and will be A-OK.

Possibly silly question I know, I just don't want to hurt my

Thanks again!