View Full Version : Automac Alternator Control...do I need it??
03-05-2012, 04:21 PM
I have a 1935 Richardson 32' Cruisabout. She is fitted with a Guest 2615 onboard battery charger and an Automac alternator control. I am considering upgrading the charger to a Genius Gen 3 smart charger. The manufacturer of the Gen 3 is unfamiliar with the Automac system, as am I. My question is this...
Given the specs of the Gen 3, will it potentially replace the Automac system by managing the alternator output under various conditions, or will the unit only handle charging from the shore power source? Here is a link to the Gen 3 unit...http://www.geniuschargers.com/GEN3
I have been able to find posts regarding use of the Automac system, but nothing about what might replace it. I am hoping that there is something out there that is more modern and more automatic.
03-05-2012, 06:23 PM
I reviewed the spec for the Genius Gen 3; didn't see any reference to controlling the alternator. The unit is, I believe, simply a multi-bank 3 stage charger. There are many makes/models of this unit on the market - I have a Guest 10 amp 3 stage charger on Altamira, and it works beautifully - left on all Winter (Virginia is not too cold, this Winter especially) - keeps the engine start and house bank at 13.3 volts, and only requires adding a bit of distilled water about every 4 months - so my 12 VDC bilge pumps are effectively backed up by shore power. Check your existing Guest charger model number - it may already be a 3 stage unit - I don't know the model. As I have said on previous posts, a 3 stage charger is the only way to really get batteries to 100% charge; unless you have a fancy expensive external regulator and a compatible alternator (Balmar, for example); and you operate the engine for many hours.
Most marine alternators (but I am not familiar with Automac) have a regulator (may be internal or external) that regulates the charging, but provides a bulk charge only. Good news is that that works for most boaters, and will not overcharge anything under most circumstances (exception being you operate the boat for 16+ hours a day).
My two cents, if the Automac is working (about 14.0 to 14.4 VDC measured at the batteries when engine has been at cruise RPM for a bit), keep it. Replacing the alternator and regulator won't get you much of anything performance wise. Consider the Gen 3 stage charger for best charging when on shore power - but check to be sure your Guest isn't already a 3 stage unit. If the Guest is a 3 stage, but not multiple bank, you might research a Nandina combiner - that would permit a single bank charger to keep multiple banksd charged. No matter what you do, remember to check the levels in the batteries periodically. You can get away a lot with batteries if you keep the electrolyte levels up.
03-08-2012, 07:16 AM
Thank you for the information Joe. The current Guest charger appears to have stopped working shortly after the bilge was washed and cleaned. I suspect some sort of relationship between the two events. The indicator light on the unit flashes momentarily when shore power is supplied, then nothing. I will have someone more knowledgeable check it out before I retire it.
Two of the three batteries onboard get drawn down over night without constant input from the charger. I suspected the automac might be to blame as I have read that they will draw 2 amps if not switched off. This one appears to not actually switch off when the switch is thrown. I guess I was hoping to solve two issues with one purchase!
03-08-2012, 12:12 PM
Some additional comments:
The Guest looks like a good budget unit. Before buying it, you might want to make sure it is properly sized to your bank so that a full charge (from discharge) can be obtained in under 24 hours. For something like a 200-300 AH system, it should do fine Properly, the shore charger and alternator are two separate systems.
There are also smart regulators (three stage) available for regulating the output of the alternator as V10 indicated. Such regulators are available from outfits like Balmar (previously named), can be fitted externally and are a good addition on a cruising boat. As mentioned, a bit of research on your end should answer a lot of questions. Three stage regulators are not cheap, but are a good idea if you are planning extensive cruising. As mentioned, they are not the first need of a charging system, especially if your shore power charger is up to modern standards and everything else is already working well. On the other hand, a faulty regulator will cook your batteries toot sweet, so if you are experiencing problems with an existing charging system, I think it pays to explore replacing the existing unit with a more modern 3 stage device.
If the boat draws down overnight from a full charge (I don't think you complained of that) then there is likely to be some sort of drain on the system and that needs to be discovered.
Three stage systems make for a much easier routine and reduce battery maintenance considerably.
03-08-2012, 12:31 PM
f the boat draws down overnight from a full charge (I don't think you complained of that) then there is likely to be some sort of drain on the system and that needs to be discovered.
use a multimeter and go circuit by circuit with the switch off. Bilge pumps, bilge alarms, washdown and wastpumps are the usual suspects for current leaks because of their typical mounting locations. But it could be anything --
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