Phase 1 was a re-fit. The original [35 amp] Hitachi was removed and replaced with a new alternator of higher output. The Hitachi was intended to maintain an engine start battery. However, it was ill suited  to restore charge of a large capacity house battery bank and could barely cope. The new 100 amp unit will be a big improvement.

In order to do a proper job the original 3/8″ V belt was changed to a 10 rib Poly Micro V belt (aka serpentine) with pulleys. This was not easily accomplished. The Yanmar 3QM30 diesel is an ancient (but solid) lump of iron that was manufactured between 1976-1980. They aren’t that common these days and it’s a challenge to find parts. As such, it was hard to locate a belt drive conversion.  I searched and made inquiries and finally found encouragement from a lone blog post from a  trailblazer who appeared to have success.

the Before (note the belt dust!)

and the After…

With the higher output, new temperature sensors on both the alternator body and battery itself were added. These talk to an advanced charging controller (fka a generator regulator) to insure long life for all components. The Hitachi had an internal regulator that output 14v regardless. This was fine for old tech lead-acid batteries but state of the art batteries are AGM and they need special feeding utilizing a 3 step charge algorithm.

Smooth running and no more belt dust and shredding failures. Over-tensioning the old V-belt would have helped to cut the slippage but doing so would overstress the water pump bearing and did I mention that parts are hard to find? There is only one guy I know of that can/will rebuild a 3QM30 fresh water pump so handle with care.

Phase 2 – Solar Energy!