External Regulator- Any Point?

[Madehn]

So my voltage regulator failed and cooked a bunch of stuff on the boat- we were able to buy an inexpensive 60 amp alternator with internal regulator that got us home-- i now have a 120 amp alternator that is fine but that i will need to purchase an external regulator in order to use again - should i go that route or should i just go buy a new 120 amp alternator complete with internal regulator. battery bank is 4 big AGMs 8ds and the starter bank is two slightly smaller AGMs. - what i most want is reliability-- a couple of hundred dollars either way wont make any difference in the long run

[steamgoat]

You may find this interesting/useful, also Mainsail sells these systems
Automotive Alternators vs. Deep Cycle Batteries Photo Gallery by Compass Marine How To at pbase.com

[fallingeggs]

Your alternator will run full bore for a few hours charging that bank, possibly resulting in the alternator cooking itself. External regulators (such as the Balmar MC-614) with their temperature sensing prevents this as it will derate the alternator when it heats up.

I'd be willing to bet that MaineSail (linked in the post above) would say that an external regulator is required for any alternator charging a large AMG bank.

But hey, your 60 amp replacement hasn't melted down yet... Maybe it will any day now or may you never deeply discharge your bank, so the alternator never works hard.

[Madehn]

THANKS!!!! quick answer that helped a lot!!!! quote from the source listed:

"AGM Batteries - I always recommend external regulation with alternator and battery temp sensing at a minimum. I have seen a number of dumb & super-dumb regulated alternators burned down by the high acceptance rates of AGM batteries. Temp compensation of the batteries is a requirement for these expensive batteries and factory alternators don't do it correctl"

appreciate the help - now to find the best external regulator

[fallingeggs]

Originally Posted by Madehn

appreciate the help - now to find the best external regulator

No problem... You won't beat the Balmar MC-614. If you don't care about the belt manager functions (i.e., you never had belt slippage / eaten through belts with the 120 amp alt before) Balmar makes the ARS-5. Others that come to mind are from Ample Power and Mark Glasser.

[a64pilot]

From a price point, Mark Grassers is hard to beat, and it works. Take the money you save and put it toward a serpentine belt conversion, you won't regret that.
It's a little conservative on temp protecting the alt, but I guess thats better than burning one up.


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[meridian28]

Sterling power also makes a good unit


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[phorvati]

You definitely need 3stage regulator as soon as you get into deep cycle batteries. If you're in texas, and relying on your 3 stage regulator to provide energy you are going the wrong way about it. Get some solar panels and let the sun do the work. Then use your "smart" regulator to make up for the difference. I have amptech and like it about as much as Balmar folks like theirs. How did you fry stuff to begin with? Regulator can fail many different ways.

[Madehn]

have added just over 1000 watts of solar since the regulator incident- not sure what caused the initial failure.

[phorvati]

We're you properly fused? Fuse of adequate size and location for each source.

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[donradcliffe]

You can buy a dumb external regulator from NAPA for $25.

[roland stockham]

You may as well say "gearbox, do I need one?" it is an essential component in a charging system. I have used the same sterling one since I built the system about 15years ago and never had a problem. My batteries are also 10yrs+ and still better than 75% capacity. Try Sterling they where a lot cheaper than Balmar and very high quality.

[Sailorman Ed]

Can a stock Hitachi be converted to external regulation?

[Sternwake]

Transpo540HD is about 25 dollars and has a potentiometer inside for adjusting target voltage.

2 screws removed the Lid.

I cut the leads to this potentiometer, soldered some wires to the legs, and remotely mounted a 10 turn 2k Ohm bourns potentiometer with turns counter.

Range is 12.8 to 15.3v

I also thermal epoxied an additional heatsink to the underside, and epoxied a K type thermocouple to alternator casing.

I am not into automatic anything concerning battery charging. Much rather have a dial to turn.

[doublewide]

You need external regulator absolutely. Your alternator puts out a float voltage too high for your AGM's. It will destroy them in a few months. They will boil off the electrolyte, dry out and die as sure as anything.