FWIW, The wire can go directly to the battery, but it gets messy quick...I go to the 50 amp circuit breaker I have installed which then goes to the main lug on the starter..Just cleaner IMO...
If you have more than a 25 amp alternator, 10 ga is too small, should be closer to 6 ga. Most marine alternators are 35 amp (I have a 50 amp...so size the wire apropriately......
GT