High Output Alternators & Serpentine belts

[Loren Beach]

The other consideration, besides ability to handle the load with a normal charge, is the possibility of state of charge dropping too low. The idea of draining batteries while cruising and having no sure way of starting the engine is pretty disturbing. If extended cruising were not part of my intended use, I would be more comfortable with a single battery bank.

Oops. I did omit that part about adding an "emergency" 12 volt battery to our boat, about 20 years ago, Currently it's a "spiral cell" AGM, in a custom mounting beneath the aft berth, I test it on a cold start once or twice a year. So our House Bank of two Trojan T-145 GC batteries is not the only DC source on the boat. At 260 AH, this House Bank provides a multi day reserve with power to start the engine after being anchored out.

 

[Christian Williams]

My third/reserve battery is mere peace of mind. If my house bank were to fail, I could still start the engine. Batteries are reliable, but sneaky. At the point they no longer hold a charge, they may still seem fine initially on the battery monitor. I formerly carried a portable car charger as backup, but a permanent install is less self-conscious. You can't hand crank a 5432, or so I am told.

 

[Vtonian]

The other consideration, besides ability to handle the load with a normal charge, is the possibility of state of charge dropping too low. The idea of draining batteries while cruising and having no sure way of starting the engine is pretty disturbing. If extended cruising were not part of my intended use, I would be more comfortable with a single battery bank.

As a project sailor of the PNW harbor hopper fleet, I assumed a $500 Craigslist Honda generator was standard issue and had it on my short list of additions. The little EU1000i is small, light, whisper quiet and way easier/cheaper to replace than the $$$ engine and more dependable than PNW sunshine on the solar gear. Just enough power to run small loads or charge batteries when all else has failed.
FWIW, my boat came with a 120A alternator and serpentine kit, and hp loss is not an issue for the 57hp Yanmar the PO installed. $1k ea injectors are though...

 

[Kenneth K]

.... and attached it directly to the alternator. Like a capacitive resistor.

Both Balmar and Sterling sell alternator protection modules for just this purpose. Should work for AGM auto-shutoff, I suppose. I have one on my old lead-acid set up to protect against 1-2-ALL-OFF switch fault or misuse.

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[Phr3d]

i just heard back from John from Electromaax about the alternator belt making a smoky smell on the Yanmar 3GM30F. And, Electromaax has a serpentine belt kit. They also have an assortment of 120 amp + alternators.

 

[peaman]

Calling either house or start makes no sense. Just bank 1 or 2. I can start the boat off of one, the other, or both. Way overkill for sure

A few other factors motivated my present arrangement. For one, I was concerned that I could put myself in a bad spot by forgetting to switch the 1-both-2 switch and either not charge the "house" bank, or discharge both banks, etc. Also, my boat has a smallish dual battery compartment built in, and the PO placed a larger pair of batteries in a nearby locker for house loads. In searching for a new, modern battery charger, I found the Blue Sea "BatteryLink" charger to have an ideal form factor and capability and it has a built-in ACR. So it is intended for service to 2 dedicated banks, through a two-pole battery switch which connects both banks separately to their respective loads in the "on" position, and it also has a "both" position for emergency situations.

I very much like that I can turn on both batteries when I step on the boat, whether for a daysail or extended cruise, and I don't need to touch the switch again until I'm ready to put the boat away until the next sail. The house bank will be used for all house loads, and will be charged by solar or engine when available. The start bank will be used only for start loads and charged the same through the ACR. I described my system in detail, with photos when first installed two years ago.

My layout seems more complex than the more common arrangement, but in use it is dead-simple, very reliable, and aesthetically as clean as one could hope (especially in a little 32 footer).