Shore power in dual battery setup

[ranger58sb]

Originally Posted by The White Whale

My Hitachi 60amp alternator outputs 14,4 volts which to my understanding is too little for AGMs.

Depends on AGM brands. Odyssey likes 14.7V or 14.8V (I forget) for bulk/absorption but Lifeline only wants 14.3V (all this at 77°F). Other makers will have their own recommendations, and mostly it also means "AGMs" and not all universally the same as each other. IOW, you should check your specific brand.

And then 14.4V from an alternator while underway can be respectable anyway, with top off happening easily enough next time you're on shorepower. Your start and windlass batteries won't need (take) much of a charge anyway, given they won't have discharged much during use.

-Chris

[The White Whale]

Originally Posted by ranger58sb

Depends on AGM brands. Odyssey likes 14.7V or 14.8V (I forget) for bulk/absorption but Lifeline only wants 14.3V (all this at 77°F). Other makers will have their own recommendations, and mostly it also means "AGMs" and not all universally the same as each other. IOW, you should check your specific brand.

And then 14.4V from an alternator while underway can be respectable anyway, with top off happening easily enough next time you're on shorepower. Your start and windlass batteries won't need (take) much of a charge anyway, given they won't have discharged much during use.

-Chris

That makes sense. In any case it sounds like there is consensus that any lead acid banks can be slightly undercharged as long as they are fully charged now and then. The question then remains whether to

1) upgrade engine bank to AGM, charge everything with shore power on AGM setting and save the cost of the victron orion

2) keep engine bank lead acid with victron Orion between it and service bank,
2a) route shore power to service bank through engine battery (battery charger on lead acid setting) as well as solar power (with mppt)
2b) charge service and engine banks seperately with shore power (battery charger on AGM setting)

From a cost benefit perspective I'm leaning to option 2 (if I can make do with only one victron Orion 12/30) and in particular 2a. I don't really have a good reason to upgrade the engine battery, I like the smart regulating effect of the victron Orion on the alternator output, and I like that I can monitor all current inflow to the house bank through the victron Orion as well.