Regulator for an Alternator?

[smac999]

I don't understand. did they remove the internal regulator and run constant 12v to the field winding? that's one of the dumbest things I've seen.

if they figured it would only run for a few mins then why even put the alt there...

[mestrezat]

That's exactly what they did except it kept producing 14+ volts not just 12. They asked me about it when they did it and since I was so new--had never seen a diesel engine until about 3 months before this, I went along with their suggestion figuring they, as "professionals" knew best and had done this to many other boats.

[atoll]

Originally Posted by mestrezat

That's exactly what they did except it kept producing 14+ volts not just 12. They asked me about it when they did it and since I was so new--had never seen a diesel engine until about 3 months before this, I went along with their suggestion figuring they, as "professionals" knew best and had done this to many other boats.

if you could be more specific,and post a photo or identify the make and model of alternator .

it would make giving advice on a fix a lot easier!
it may just be a case of swapping out the bodged units,or attaching a wire if the built in regulators are still present!

[Neptune's Gear]

Personally, I don't agree with those who say to put in the internal regs again. The internal regs are automotive ones, very basic, and designed only to return engine starting currents and run a few lights. While this may be OK for the start battery, it is not OK for the deep cycle house bank. A proper, hot rated alternator with a 3 stage temp compensated regulator is the only way to go. It will charge the batts as fast as possible - without overheating them. There is a balmar agent in phuket who can sort this system properly - run by a kiwi if I remember correctly. Either he or I can send you the appropriate regulator if you wish. Balmar, or next step or similar is the way to do it properly. Oh yes, the bad news is you will almost certainly need new bats as well. Also, there is a boatyard in Penang that can help. Send me a pm if you're stuck. Good luck!

Sent from my Nexus 7 using Cruisers Sailing Forum mobile app

[mestrezat]

It used to be an old AC Delco if memory serves me but having been rebuilt a few times, I'm sure there is nothing left of the original guts in it. It's not a big and beefy alternator since it only has to top off the start batteries but the house.

[bletso]

I remember the good old days, well, the old days where the regulator was mounted on the fire wall and consisted of three or four relays. Now it's a potted part and I can't stick my grubby inquisitive fingers in it to fix things, (yea, sure)!

[colemj]

Originally Posted by Neptune's Gear

Personally, I don't agree with those who say to put in the internal regs again. The internal regs are automotive ones, very basic, and designed only to return engine starting currents and run a few lights. While this may be OK for the start battery, it is not OK for the deep cycle house bank. A proper, hot rated alternator with a 3 stage temp compensated regulator is the only way to go. It will charge the batts as fast as possible - without overheating them. There is a balmar agent in phuket who can sort this system properly - run by a kiwi if I remember correctly. Either he or I can send you the appropriate regulator if you wish. Balmar, or next step or similar is the way to do it properly. Oh yes, the bad news is you will almost certainly need new bats as well. Also, there is a boatyard in Penang that can help. Send me a pm if you're stuck. Good luck!

If the OP was looking to buy a new alternator for his house bank, then what you say makes sense. However, he already has an externally-regulated alternator on his house bank and is looking to fix a small automotive alternator for his starting battery in which the internal regulator was removed. Even putting an external regulator on this alternator for its purpose is way overkill.

I think having a dedicated alternator for the start battery is a poor idea because it is wasted for 99.99% of the time it is running - he should instead put that output onto the house and use a combiner or like to top off the start.

Mark

[Dockhead]

Originally Posted by Rusty123

Depending upon what make and size of alternator you have/need (and you don't need much if it's dedicated to your start battery), you might be able to purchase a used or remanufactured internally regulated alternator for not much money (certainly less than a three step external regulator). I think an external regulator is overkill for a dedicated start battery (equivalent usage to your car).

I agree.

Alternator internal regulators are designed for charging start batteries. And they work fine for this purpose. That's what I would do for an alternator dedicated to a start battery.

Internal regulators do a poor job charging house batts, which are often chronically undercharged with internal regulators. You do really want external regulators for this.

Balmar is a good one, but not the only choice. Sterling have a clever system which people seem to like. I use an Adverc, with which I have been extremely pleased.

No regulator at all??? I agree with the above comments that this is just crazy. Some people use solar panels with no regulator with decent results when the panels are small compared to the battery capacity, but not alternators!!!

[Neptune's Gear]

If its only the start bat alt, a simple, single stage external reg is probably cheapest and easiest - like these http://store.alternatorparts.com/specialregulators.aspx pretty much like what was internal before.....

Sent from my Nexus 7 using Cruisers Sailing Forum mobile app

[hellosailor]

I had a Found On Road Dead in the good old days with the regulator being a box of relays on the firewall. And at least twice a year it needed adjustment or replacement. The integral solid state regulators are WAY more accurate and efficient and durable. Arguably cheaper too. Harder to repair, sure, but way less likely to ever need repair.

Could be the shop removed the internal regulator because it was bad and they couldn't get a handy spare. If a shop isn't placing wholesale orders every week, it may not be practical (in time or money) to special order one replacement part from the wholesalers, who usually aren't local. A regulator that cost $25 wholesale from a national supplier (20 years ago) was $100+ from local auto dealers who could get it next day as a service part. The same $100 would buy a used (junkyard) alternator in good condition with a 90-day warranty, or a junk quality "allegedly rebuilt" one.

The shop might have intended this as a temporary kludge. Or maybe they were just evil.(G)

[colemj]

It sounded like the shop questioned this being done, but the "electrician" demanded it.

Mark

[Tripod]

Originally Posted by hellosailor

The shop might have intended this as a temporary kludge. Or maybe they were just evil.(G)

Or maybe they sell batteries too.

[Fuss]

Originally Posted by colemj

If the OP was looking to buy a new alternator for his house bank, then what you say makes sense. However, he already has an externally-regulated alternator on his house bank and is looking to fix a small automotive alternator for his starting battery in which the internal regulator was removed. Even putting an external regulator on this alternator for its purpose is way overkill.



I think having a dedicated alternator for the start battery is a poor idea because it is wasted for 99.99% of the time it is running - he should instead put that output onto the house and use a combiner or like to top off the start.



Mark

Absolutely...
An alternator dedicated to the start battery is such a waste of resources.
Replace it with another high output one to the house bank.
Echo charge the start battery from the house bank.

You see it time and time again, an alternator dedicated to the start battery. Some systems are even designed to priority charge the start battery first on the basis that it's so important.
The only thing important about the start battery is that it is only used for starting and nothing else.

[Dockhead]

Originally Posted by Fuss

Absolutely...
An alternator dedicated to the start battery is such a waste of resources.
Replace it with another high output one to the house bank.
Echo charge the start battery from the house bank.

You see it time and time again, an alternator dedicated to the start battery. Some systems are even designed to priority charge the start battery first on the basis that it's so important.
The only thing important about the start battery is that it is only used for starting and nothing else.

I think on the contrary that an entirely separate start batt with its own (small, cheap, car type) alternator and no connection to the house batts or charging system is very sound system architecture.

Engine start may be a life safety critical function. The less points of failure for that, the better.

Especially when it's so easily arranged - the alternators marine diesels are delivered with are not suitable for charging house batts anyway. So why not just leave them in place to charge the start batt, and add a second continuous rated, high capacity alternator designed for producing power in bulk, for charging the house system? Simple, redundant, and good system design, in my opinion.

[Rusty123]

Originally Posted by Dockhead

I think on the contrary that an entirely separate start batt with its own (small, cheap, car type) alternator and no connection to the house batts or charging system is very sound system architecture.

Engine start may be a life safety critical function. The less points of failure for that, the better.

Especially when it's so easily arranged - the alternators marine diesels are delivered with are not suitable for charging house batts anyway. So why not just leave them in place to charge the start batt, and add a second continuous rated, high capacity alternator designed for producing power in bulk, for charging the house system? Simple, redundant, and good system design, in my opinion.

An opinion shared by Nigel Calder, as well.