Move hitachi alternator wires to house instead of engine battery

[GBS]

Hey all, 

I'm curious if anyones rewired their Hitachi (my engine is a Yanmar 3GM30F) alternator to connect directly to the house battery instead of the engine battery thru the starter, which is how I understand the default Yanmar wiring is.  If so I have a few questions about wiring and if it made a difference to charging a larger house bank.

thanks!

[GBS]

ok I didn't want to resurrect a dead thread for nothing but thought I'd report what I discovered in doing this. I've read a bit online and in documentation about alternators and decided to give this a try. I've been struggling with charging from the standard alternator, had it tested and discovered it was bad. I got a new hitachi, the 90Amp model that fits the 4GM30F but is a bit bigger than the regular 55 I had before. Charging was improved but as soon as I put loads on the batteries the voltage, at battery,  would drop from the no load 14.2-14.3 to 13.6. I heard one of the fixes is to connect both + and - straight to battery, as well as the sense wire to + on battery. 

I did the wiring today using 4 gauge wire to a stud fuse on the battery and to my surprise its now charging at 14.2 at idle, running at higher RPM with/without prop load. Also turning on all electronics, including radar and fridge still kept the voltage exactly at 14.2. There are also a few other reasons such as shutting off the power switches would open circuit the alternator output but I mostly did it because of my charging issues. I've had limited long term experience of course but the charging system is behaving more like everything I've read it should and all in all a simple install once I got over my high amp fear and figuring what battery is in fact being charged and how the alternator is connected.

I'm still curious why there was a drop when turning on the loads but I suspect the harness for the alternator, all the connectors creates a drop that the regulator in the alternator doesn't recognize but does now that its wired directly to the destination for the charge. Curious if anyone has opinions but this seems a much better setup, as many experts say. I'm thinking a smart regulator would improve results even more but I think this is a good upgrade for reasonable cost.

Cheers!