Fusing the alternator-battery
 

I have my Optima battery in the trunk. I have one thick wire from the alternator (100amp) directly to my battery. Do I fuse the battery at 100amps?
Seems logical but I am not sure.

No need to fuse the alt to battery - the alt already has a built in regulator. It'll never put a 100 amps into the battery - the battery wouldn't allow that. Batteries really charge on VOLTAGE not really amperage and the regulator in the alt is voltage based.... so you're good.

A circuit breaker or fusible link from the battery to the STARTER isn't a bad idea - although you rarely see anyone do that.

Some wiring harnesses are shipped with fusible links in the ALT to Battery connection but most of those run thru the "fuse box"....

I go from the Alt to the starter on the Battery side

Hey Greg,

You know of any Circuit breakers that can handle cranking amperage on car batteries?

Doing my electrical system now couldn't find anything other than really Mad Electrical's Ford Solenoid, so at least the starter cable is only hot during cranking.

When I rear mount batteries I will use a 100amp 12v breaker near the batt for the alternator feed. Great if for some reason the wire rubs through or when you need to service the alternator you can trip the breaker.