The stock 55 amp alternator (see picture) on the boat may be fine for standard day sailors. However, given the heavy loads involved with living aboard yet still be able to get out of the marina with all the electrical stuff (TV, DVD, Microwave, Gamecube, Radar, GPS, etc.) upgrading to a high capacity alternator with a smart regulator seemed a requirement. Also, since I am using heavy duty 6 volt AGM batteries which require the charging be carefully monitor to avoid damaging them I was further compelled to upgrade.
The process to upgrade the alternator is not a straight forward as it may seem. I tried unsuccessfully to locate the proper high output alternator and was disappointed that none of the alternators that West Marine stocks would work. Out of desperation I consulted the manufacturers and was referred to Peter Kennedy, who I later found out was a rather renowned expert in the field. He promptly replied to my email with the needed parts, which he offered to package and sell to me via his website, http://www.pkys.com. Also he provided step by step instructions which proved to be extremely complete and accurate. Thanks Peter for the excellent instructions.
The 27 hp Westerbeke diesel engine being rather small would not handle much more than the 75amp Balmar model 90-75 he recommended. Mounting requires a non-standard 8mm mounting bolt which is rather long, and did take some cross town trips to locate. The white case and blue fan makes the new alternator stand out from the red paint that coats every part of the engine.
The standard max charge regulator is mounted in the compartment next to the engine. At first I had it up high in the unused space (see picture); this made reading its status and insuring it was working inconvenient so I relocated it lower on the aft bulkhead of the compartment where it could be plainly seen with the hatch open.
In general the most difficult issue is running the large battery cables through the boat. It starts rather easy going aft from the engine into the port locker than forward via the port aft bunk, which has a run for wiring which is covered by a access panel only held in place by three screws. From here is the hard part, since the wire must go under the floor to the battery compartment. The battery temp sensor wire just reaches the batteries with perhaps 2 inches to spare. The wiring looks rather intimidating once everything is hooks up. The fuse (not shown in picture) is connect directly between the battery and the positive cable. This reduces the voltage drop to the bare minimum to facilitate the best possible charging flow. Introducing fuse blocks or switches quickly builds up resistance and results in both heat and voltage drop, which would defeat the whole purpose of putting a high output, smart regulated charging system in.
The alternator and regulator performed as expected and produced precisely the required charging voltage after gradually ramping up during start up. To finish off the job before going offshore, I would still need to anchor the batteries so they are held down. The four 110amp 6 volt AGM batteries fit the compartment so tightly there is no space for them to move any direction but up; which as you can see from the picture adding anything to hold them down will not be easy. But that as they say, is another story; I will add another page documenting that project when it is complete...