Griso 8v blowing B fuse and won't start, what's up?

[actwin]

 Went to start my 2011 Tenni Griso for the first time this year,today and hear the click, snick sound. The B fuse was blown so I replaced it and blew it again. The battery shows 50% charged so I swapped it with the B1100 battery and it fired right up. I let it run a couple minutes, shut it off and hit the starter again, click, snick and blown B fuse. I put the battery back in the Breva and went for a ride , now I need to find the problem, it did this to me last year but after I replaced the fuse it has been fine till today. I'm gonna get a new battery for sure, this one is 7 years old. Any help would be great.

[beetle]

Check the connections in your starter motor, both positive and ground. This can also be contributed to bad battery connections, but if you swapped batteries from the B11, then your connections are probably OK. This is the common 'startus interruptus'. Some folks throw in a 20 amp fuse and are OK. The wiring goes through the ignition switch to the starter relay and sometimes there's enough voltage drop to prevent start. If you rewire directly from the battery to the starter relay, this is usually a permanent solution.