This is an old Ducati favorite. Bike doesn’t want to turn over and is a poor starter. Many’s the good battery blamed unjustly for the problem. And it’s not the starter motor either. It’s the cables. Apparently they build up resistance over time. But to be honest, fitting such spindly cables in the first place looks like a triumph of hope over experience. Easy fix. New cables all round: battery-solenoid; solenoid-starter motor; and a new earth strap to double-up with the original. Easy to make yourself. Buy all the bits from Vehicle Wiring Products.