trek powerfly 5

Hi, this afternoon I wheeled my Trek Powerfly 5 out of the garage to go for a nice ride in the sun, only to discover that the battery (Performance Line 500) is totally dead. I am not getting anything at all on the Purion display, and when I take the battery out of the frame and plug in the...

I am almost at the point of getting this bike, for both road and off road use. Any thoughts or experience with this bike. I was going for the Trek powerfly 7 HT for £2800 but saw that you can get the Trek Powerfly 5 FS for £3000 slightly less spec though, will be for road and off road use.