917.254422, Onan 20HP Twin...Turn key on, indicator light comes on, try to start and light fades immediately.
Hook up charger with 50 amp boost and it starts.
All terminals etc. are clean.
Once it is running for a few minutes and turned off it will start with no problem.
This battery is less than 2 years old and only used to start, electric pto and deck lift, headlights never used.