Zanshin I High-output Alternator

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The standard alternator that ships with a Jeanneau 49DS is a 55Amp device. This output is reached only when the engine is running at relatively high speeds and at more common engine RPM speeds of around 2000 it only produces about 30-40 Amps. That would mean that I'd need to run the diesel for roughly 10 hours in order to half-charge the bank (880Ah total capacity and I'll assume that the charge rate is constant). Zanshin I was commissioned with the optional 80Amp alternator, and that will put out about 50Amps@2000RPM, reducing my 50% charge time by an hour or perhaps a bit more. In December 2009 when my Fischer Panda generator became inoperative and needed repairs which I didn't wish to make the time for, I opted to further reduce my battery load time by purchasing and installing a 120Amp Hitachi replacement alternator. Now, at 2000RPM, the batteries are charged at over 80Amps, effectively doubling my charge rate and cutting load time in half.
The rate at which batteries can be charged is a function of their type and capacity, on Zanshin I that means anywhere from 88Amps to 220Amps (using 1/10th to 1/4th capacity). This additional amperage also necessitates using thicker cables from the Alternator to the regulator. I would have chosen an even larger alternator, but larger ones require using two belts instead of the single one on my engine, and that would have required major changes on the engine front. I do intend on getting a second alternator installed at some point in the future, but need the help of a machine shop so that they can make the mounting for it, and at the moment I prefer to be out sailing instead of ashore somewhere and waiting for work to be done.

This is the new 120 amp alternator installed on Zanshin I which replaced the 80 amp model. It was essentially a plug-and-play installation, taking only an hour or so - which in This is the new 120 amp alternator installed on Zanshin I which replaced the 80 amp model. It was essentially a plug-and-play installation, taking only an hour or so - which in "boat time" means that it was very quick indeed!
This is the new 120 amp alternator installed on Zanshin I which replaced the 80 amp model. It was essentially a plug-and-play installation, taking only an hour or so - which in "boat time" means that it was very quick indeed!
The companionway steps have been removed for easier access to the engine compartment and the shiny new 120 amp alternator has been installed and tested. The companionway steps have been removed for easier access to the engine compartment and the shiny new 120 amp alternator has been installed and tested.
The companionway steps have been removed for easier access to the engine compartment and the shiny new 120 amp alternator has been installed and tested.
Old and New alternators The original 80a and the new 120a alternators on Zanshin I
Old and New alternators
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