Selecting an Alternator

[hanleyclifford]

Not sure why you wanted to bump this thread. In the time that has passed since I first put that bracket on the engine I am more convinced than ever the alternator should be mounted this way. Quite apart from the charging advantage, this change frees up the accessory drive position for a water pump so the FWC system could have two mechanical pumps. I wonder if even the Catalina 30 crowd might be able to make room for that sheave on the flywheel (about 5" needed)?

[sastanley]

Hanley, No way... even if we removed the flywheel housing, any pulley attached would rub the settee 'box'. The bottom of the flywheel housing is less than 1" from the dinette box, the top, maybe 4".

I'll take a picture the next time I am at the boat for you. But thanks for thinking of us!

FYI - when Catalina started putting in diesels instead of the Atomic 4, they had to cut into the seat cushion to accommodate the engine's height..it was already tight when they shoehorned the A4 in there!

[jerkeene@gmail.com]

New Alternator and Smart Regulators?

Hello, I'm rewiring my old 78 Ranger 33 this winter, adding a 200Ah house battery bank (probably gel cell), and replacing the stock alternator. Two questions:

Will the 55A alternator be sufficient or do I go with the 120A high-output alternator? After reading Don's old post in this thread, I'm leaning toward the bigger one.

These are internally regulated. Everything I've read says to use a multi-stage smart regulator to get full charge without damaging the batteries. My goal is to keep it simple, but the batteries are going to run $600-700. Do I invest another $300 in the smart regulator? And if I do that, do I need an alternator that is not internally regulated?

Thanks for the help!

[edwardc]

Keep in mind, as Hanley has frequently pointed out, that you're not going to get 120A out of any alternator driven off of the accessory drive. You just can't spin them fast enough to get the rated output. It will run cooler, however, and probably last longer, so that's a reason in favor of a higher rated alternator.

Hanley had to mount a huge pulley on the front take-off and mount the alternator up there in order to get a 3-to-1 ratio to spin the alternator fast enough. And he found that it was lugging the A4 too much. You've essentially turned it into a 30HP generator, with little power left to push the boat! He has since backed off to a smaller 2-to-1 rig.

As for the multi-stage smart regulator, you really want to go that way. Not only will it help maximize your battery life, but it will minimize the amount of engine run time required to charge the batteries. The built-in internal regulators are essentially automotive regulators, and back-off to a trickle charge way too soon. Any decent alternator shop should be able to modify an alternator to bypass the regulator and bring out the feild terminals. Just be sure they know its for marine use so they install the proper seals to protect against igniting any gas fumes. The smart regulators will pound the amp-hours into the batteries at the fastest rate they will accept it, until they're about 80% charged. Only then will it back off to a slower charge rate for the last 20%, and then back off to a trickle/sustaining charge.

This minimized engine runtime becomes important when you're passage making, and have to run the engine so many hours each day to maintain your "power budget".

[joe_db]

http://www.morganscloud.com/category/electrical/

Follow all the AGM discussions on there. You may end up thinking twice.

Hello, I'm rewiring my old 78 Ranger 33 this winter, adding a 200Ah house battery bank (probably gel cell), and replacing the stock alternator. Two questions:

Will the 55A alternator be sufficient or do I go with the 120A high-output alternator? After reading Don's old post in this thread, I'm leaning toward the bigger one.

These are internally regulated. Everything I've read says to use a multi-stage smart regulator to get full charge without damaging the batteries. My goal is to keep it simple, but the batteries are going to run $600-700. Do I invest another $300 in the smart regulator? And if I do that, do I need an alternator that is not internally regulated?

Thanks for the help!

[roadnsky]

Hello, I'm rewiring my old 78 Ranger 33 this winter, adding a 200Ah house battery bank (probably gel cell), and replacing the stock alternator. Two questions:

Will the 55A alternator be sufficient or do I go with the 120A high-output alternator? After reading Don's old post in this thread, I'm leaning toward the bigger one.

These are internally regulated. Everything I've read says to use a multi-stage smart regulator to get full charge without damaging the batteries. My goal is to keep it simple, but the batteries are going to run $600-700. Do I invest another $300 in the smart regulator? And if I do that, do I need an alternator that is not internally regulated?

Thanks for the help!

An important question...
Will you have SHORE POWER available on a "regular" basis?

[Mo]

I've had a Delco 90 amp with internal regulator on mine for 4 summers and am pretty pleased with it. I use the boat during summer almost every day and we spend most weekends aboard, either on a little cruise or in the surrounding area. Running two marine starter batteries and always have starting and light power.

Also have a 1000 watt inverter. The only thing about that is that I need the engine running to run the vacume cleaner. I think if I was cruising I'd have a larger battery bank, but for what I do it works fine. It's nice to have something that will throw a charge back into those batteries.

[joe_db]

FYI : I am unhappy with my AGMs and will go back to gels next replacement.

[jerkeene@gmail.com]

An important question...
Will you have SHORE POWER available on a "regular" basis?

No. We are setting the boat up for a year-long cruise, so shore power will be "irregular" at best. I'm planning to add two 80W solar panels to supplement charging with the engine.

I'm definitely concerned about robbing power from the prop - I think I'm over-propped already.

[edwardc]

FYI : I am unhappy with my AGMs and will go back to gels next replacement.

Joe,

What's the source of your chart?

[joe_db]

East Penn Deka, maker of my batteries.
I used their gels and got over a DECADE of service. Now on year 4 their AGMS are about beat. I really made a mistake switching. I have been studying this a lot lately and have come to the conclusion that AGMS are inferior in every way but one: They tolerate higher voltages.
Thus they can be used in cars and airplanes without advanced adjustable regulators and thus a vastly larger market.

http://www.dekabatteries.com/assets/base/0139.pdf

QUOTE=edwardc;46109]Joe,

What's the source of your chart?[/QUOTE]

[jerkeene@gmail.com]

As for the multi-stage smart regulator, you really want to go that way. Not only will it help maximize your battery life, but it will minimize the amount of engine run time required to charge the batteries. The built-in internal regulators are essentially automotive regulators, and back-off to a trickle charge way too soon. Any decent alternator shop should be able to modify an alternator to bypass the regulator and bring out the feild terminals. Just be sure they know its for marine use so they install the proper seals to protect against igniting any gas fumes. The smart regulators will pound the amp-hours into the batteries at the fastest rate they will accept it, until they're about 80% charged. Only then will it back off to a slower charge rate for the last 20%, and then back off to a trickle/sustaining charge.

This minimized engine runtime becomes important when you're passage making, and have to run the engine so many hours each day to maintain your "power budget".

Thanks for the advice on the smart regulator, that's the way I will go. Does anyone have a recommendation on an externally regulated alternator that will easily fit in place of the stock A4 alternator? Seems like I should be able to buy what I need without having to modify.

[joe_db]

"Marine" heavy duty externally regulated alternators are very expensive. Delco makes a number of 1 and 3 wire alternators that fit the A4 and can be modified for external regulation, as can the stock Motorola. They are all over FleaBay and also found on this very website.

[BadaBing]

Alternator and blocked arteries

I am seriously considering upgrading my alternator. I’m currently running on a rewound 35 amp atl. Over the past 7 years I have added lots of comfort add-ons that eat up power, stereo, wheel pilot, forward looking sonar, VHS radio, a 3000 watt inverter and the monster consumer, a 2 Gal 11 Amp draw (120 v) water heater. ( 3 large marine batteries #1 a single , #2 2- house)
On a very long sail, over the course of a day, switching back and forth between batteries and refreshing them with a charge I can reheat the water heater for the next nights anchorage.

However, it is a long process as the inverter draws the batteries down, ALL, in about a half hour and it takes another 2-3 to replenish them.
Solution? Speed up recharge tome with a larger alt. ( I considered a Honda or Yamaha 2000 gen. but am leaning far away from that option) After reading the above thread . Moyer's newly offered 70-120 alt seems to be about the best choice and the largest that the A4 could reasonably drive.
After reviewing the wiring for the T30 and the posted wiring schematic offered by Mr. Moyer ( THANK YOU) It looks like adding a larger atl is like having a clogged aorta, pushing more blood won’t help if we have a clog.
The Alt charge wire is a 8ga. Wire and runs a loop, from the alt to the ign switch, to the amp meter, and back to the battery switch, where the wire size jumps up to 4 Ga. (?) battery terminal wire. The 8Ga. length, not counting the small circuit size in the switch and gauge is well over 20’, likely closer to 35’.

It occurs to me that I (we) are attempting to push larger and larger volume and pressure of current through a very small wire, sort of like pushing a 3” fire hose through a ½ water pipe.
The result, so I am thinking, is that the Alt. works much harder to PUSH the current and the wire restricts how much can actually be pushed through it.
Ill going to run a couple tests on my idea but I wanted to share the thought with you all.

My thinking is upgrade to a 70-120 Alt. and to shorten the run from the alt to the battery, actually down to 3-4 ‘ directly to the battery switch, use a larger gauge 6?? Possibly 4) charge wire and see if I can add on a remote type amp meter so that the charge current does not need to pass through the ignition switch and the amp meter. Sort of a double bypass surgery. I think this will improve charge rates and reduce load on the alternator.
Any thoughts?

[joe_db]

You can do something like this:

I am seriously considering upgrading my alternator. I’m currently running on a rewound 35 amp atl. Over the past 7 years I have added lots of comfort add-ons that eat up power, stereo, wheel pilot, forward looking sonar, VHS radio, a 3000 watt inverter and the monster consumer, a 2 Gal 11 Amp draw (120 v) water heater. ( 3 large marine batteries #1 a single , #2 2- house)
On a very long sail, over the course of a day, switching back and forth between batteries and refreshing them with a charge I can reheat the water heater for the next nights anchorage.

However, it is a long process as the inverter draws the batteries down, ALL, in about a half hour and it takes another 2-3 to replenish them.
Solution? Speed up recharge tome with a larger alt. ( I considered a Honda or Yamaha 2000 gen. but am leaning far away from that option) After reading the above thread . Moyer's newly offered 70-120 alt seems to be about the best choice and the largest that the A4 could reasonably drive.
After reviewing the wiring for the T30 and the posted wiring schematic offered by Mr. Moyer ( THANK YOU) It looks like adding a larger atl is like having a clogged aorta, pushing more blood won’t help if we have a clog.
The Alt charge wire is a 8ga. Wire and runs a loop, from the alt to the ign switch, to the amp meter, and back to the battery switch, where the wire size jumps up to 4 Ga. (?) battery terminal wire. The 8Ga. length, not counting the small circuit size in the switch and gauge is well over 20’, likely closer to 35’.

It occurs to me that I (we) are attempting to push larger and larger volume and pressure of current through a very small wire, sort of like pushing a 3” fire hose through a ½ water pipe.
The result, so I am thinking, is that the Alt. works much harder to PUSH the current and the wire restricts how much can actually be pushed through it.
Ill going to run a couple tests on my idea but I wanted to share the thought with you all.

My thinking is upgrade to a 70-120 Alt. and to shorten the run from the alt to the battery, actually down to 3-4 ‘ directly to the battery switch, use a larger gauge 6?? Possibly 4) charge wire and see if I can add on a remote type amp meter so that the charge current does not need to pass through the ignition switch and the amp meter. Sort of a double bypass surgery. I think this will improve charge rates and reduce load on the alternator.
Any thoughts?