I had a similar problem on my bike, two days after I bought it. It was cranking slowly and almost didn't start. My dealer's mech. found that both cables were loose. The next day I shut it off at an errand and came back 5 min. later and it wouldn't crank at all. A fellow Triumph rider with a new Bonneville was parked next to me, and he fetched a set of cables and got me going (Cheers, Mark!). When I got to my dealer they checked it with the scan tool and it showed a defective battery. With the new battery, so far, so good. It fires after 3-4 cranks, even when hot.