High output altenators

[admiralslater]

I have installed 5 of the Firefly Carbon plate batteries on our Outremer. We have about 600 watts of solar controlled by 2 blue sky mppt 2512i units. Our engoines have the standard yanmar alternators on them.

I was reading the Firefly thread and some mentioned that if you have high acceptance batteries that you Must charge at a high rate other wise you damage your batteries. Do I need to replace the alternators, or did I misinterpret the statement

[a64pilot]

AGM batteries will accept higher charge rate, having said that I doubt many have the charging sources to be high rate.
I have 185 amps of charging and a 660 AH bank of Lifelines, and even at 185, the batteries in theory would take much more than that. I say in theory because they have to be well down on charge, this morning I was down about 20%, cranked the generator and the chargers stayed in bulk for less than three or four min., then they hit absorption voltage and of course then charge current slowly begins to lessen.
Add to that that it is my opinion that small frame high amp alternators rarely put out rated current for long, heat builds and the regulator turns them down to protect the alternator.

If I were you, I would keep my alternators, but add programmable regulators, if for no other reason than I'd bet their voltage is not what the Firefly batteries would like to see.


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[admiralslater]

A64pilot,
I should have mentioned that I use balmar 614 s and have set them up as required by Firefly. I know that they get to absorption as the idiot lights come on the panel as the regulators shut down the alternators.
Electrical is not my strong suit, would love to get he boat into mainsails hands for a week or two

[exMaggieDrum]

You certainly need to use the alternator temperature sensors with the Balmar 614 to protect your alternators.

[molo0928]

Could you please state what the Firefly's require? Thanks

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[admiralslater]

Originally Posted by molo0928

Could you please state what the Firefly's require? Thanks

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The manual (which is on line ) says charge at 14. 4 and float less than 13. 2. They don't want them float charged