Yeah,could be a wiring fault,.....like a trapped or chafed wire somewhere.Around the headstock is a common area.As with a previous post,...time to get busy with a multimeter.Doubt it is a duff cell,...but yer never know.It's gen one sorry should have stated that unless the new battery has a bad cell
sounds like a winner. no idea about the nitro, but the battery is something I'm usually ok with a premium for quality. got a yuasa in every one of my last 3 bikes and never been stranded.
that being said, I've tempted fate, and shall be noting down the roadside assist # now for use later today
cheers