External alternator regulator

[Mike Schmidt]

Is it advisable to have an external regulator on the alternator (19SI) to deliver a much better charge profile for my AGMs? I’ve read quite a bit of literature from different manufacturers, and the Balmar MC-614 looks like a good unit, but some objective advise would be welcome at this point. It’s also unclear to me how complicated it would be to hook up the MC-614 to my 19SI alternators.

My setup is twin 6BTAs w/ 19SI alternators running to AGM start batteries which are connected to VSRs (cut in at 13.8V) to AGM house batteries

Topic

[Swimmer]

Voltage Regulation follow up question

I have the stock Delco 22SI/160A alternator on my 2018 QSB. I have read the above comments and a few articles on the subject of voltage regulation for better battery charging.

My current use is 4 to 5 hour runs, a 10 hour periodically. That may change in a year if we do the ICW/Loop so much more frequent and longer runs. I have 960Amp hr AGMs.

A few questions :

1. Would it make sense to get a smart alternator for my future use case? 

2. External voltage regulation on the existing Delco, or..

3. A new alternator such as a Balmer with the built in voltage regulation preferred? We live on the boat 6 months per year, and I have alot invested in the AGMs (new 2023) so I don’t mind making the investment if it makes sense.  

[firehoser75]

Mike,
Clark hits good points regarding your use of your boat. That is a very important factor.
I am going to assume the reason you are “tweaking” your stock alternators is that they are not currently meeting your expectations. Depending on what battery type your house bank is (flooded lead acid, AGM, Firefly, Lithium, etc.) your time required to recharge will vary. For example, even with an alternator that is well setup for charging the house bank (external regulator with alt temp compensation), it will take 5-6 hours of run time to fully recharge FLA batteries. They will only accept a very small amount of charge for the final 5% of charge, and if you constantly operate FLA or AGM batteries at a PSOC (partial state of charge – meaning not 100% fully recharged regularly) the batteries will have a shorter than optimum lifespan. What you can gain by changing your alternators to external regulation, is a more effective charge during the “bulk” stage (going from 60% to 90%) and a better acceptance voltage compared to a stock alternator. However, unless you do long runs regularly you will not achieve fully recharged batteries often enough.
If you are going mainly from anchorage to anchorage, I would recommend installing some solar panels to complete the final “push” to fully recharge (100%). Over time, the cost of solar will most likely pay for itself in terms of longer battery life. A battery monitor (like the Balmar Smart Gauge, Victron, etc.) is a good investment to let you know what is happening with your batteries at all times.
There are many factors and variables involved in this so some research is needed to understand it and to get the best value from your money spent, which also leads to less problems when out on the boat.

1 user thanked author for this post.

Mike Uliasz

[Tony Athens]

Clark,

One of the features I really like is that the DVM’s are on 24-7-365.. The second you get on your boat, you know exactly what going on…Always a good feeling.

Thanks for your “confirmation”..

[Clark Leighs]

I agree with a direct to the battery Vmeter and yes, fused at the battery. I have not done it ,YET, but it will be done this winter. I have picked mine.

That way you know exactly what the battery is getting from the charge source and how they are handling the loads when the charges sources are OFF. It could be a tip off to a developing problem that has not become bad enough to show in other ways..

EDIT: If your alternator regulator is going haywire, a too high voltage, they will tip you off that something is amiss long before most other means will.

[Tony Athens]

Clark,

What are you thoughts about monitoring Battery Terminal Voltage as in this article? I know you’ve been around the block with DC power distribution on a boat, and the fact that you are into remote regulators in some applications, offering your take on “seeing” what is actually taking place at the batteries would be valuable to our readers..

Installing Digital Volt Meters (DVM) on Your Boat

[Clark Leighs]

Almost without exception you will need to have the alternator modified to be operated by an external regulator.
I have a 22SI that I mod. about 10 yrs ago.
I am replacing that with a 24SI , again to be modified to be run by an external regulator.

With a Balmar reg. get and install the alternator temperature sensor. If you don’t and you run the batts down then the regulator may cook the alternator without that protection. Actually any external regulator should be able to be so equipped.

A lot depends upon how you use the boat. If you are a marina hopper and plug in, charger on, most nights then I suspect you don’t need it.

If you are mostly a fisherman out for the day and then back at night with the boat plugged in , charger on, then again I suspect you don’t need it.

If you spend a lot of time on the hook , running from anchorage to anchorage, depending upon the alternator to recharge the batteries then it is a good way to go. I will suggest that if the latter is your use then do the mods to your 19SI but keep an eye on the batteries. If you are still not getting the charge needed between anchorages then you may need a larger output alternator. But the external regulator is a good start.

THe 19SI and the 22SI are now obsolete although parts will be available.

I don’t use the Balmar but from my friends who do they are a good regulator but they do take some effort. Don’t be afraid to call Balmar for help.

I am also going to suggest the following for you to read.

https://www.trawlerforum.com/forums/s4/balmar-mc-614-regulator-settings-16464.html

1 user thanked author for this post.

Tony Athens

[Richard G Cook]

My boat has a single 6BTA 5.9 M3 330hp, originally with the stock 19SI alternator. My batts are all AGM.

I bought a replacement alternator from Seaboard that fit exactly but put out more amps – 145 amps vs the stock 19SI’s 105 amps. An alternator shop converted the new unit to external regulation ($86). I installed it with the Balmar 614 regulator, including battery and alternator temperature sensors connected to the 614. Works great – much better than the stock setup.

You could wire one existing alternator to charge the start batteries for both engines, and use an upgraded and externally regulated alternator to charge the house battery bank, where it makes more difference. Or you could convert one stock 19SI to external regulation.

I kept my stock 19SI as a spare. If either the upgraded alternator or the Balmar 614 failed, the stock 19SI could be re-installed, reverting to internal regulation until the newer equipment was fixed.

[firehoser75]

Hi Mike,
You are correct in that most stock alternators are not set up nor designed to charge a house bank on a boat (even more of an issue if the bank is relatively large). What they are usually set up to do, is to put a “top up” charge into the start batteries which means they do not put out at a high rate for very long (think car alternator). To change your alternator(s) to external regulation will require changes to the alternator itself. When I did this on my sailboat (some years ago), I took the stock alternator into an auto electric shop and had them do the work to remove the internal regulation and set it up for the attachment of the same Balmar unit you are talking about. I do not know if that Balmar can connect to 2 alternators at the same time or if you will need 2 Balmars??? I suspect you will need 2 Balmars.
You will have to set it up to temperature compensate for alternator temp or you will burn out the alternator(s) as they are not designed to run at “full” output for long periods of time. Forcing them to do so, in a hot ER will kill them. If you are relying on your alternators to meet most of your charging needs, you may be better to switch to alternators that are designed for high output (even these need temperature monitoring and compensation). Balmar and others make high output alts.
My intent here is to give some general info, look for more detailed and complete answers from the “pros” here.

[Mike Schmidt]

What I mean by “charging profile” is the voltage at which the alternator charges the batteries. Since different battery chemistries require different voltage (e.g., LA = 14.2v-14.5v vs AGM = 14.6v-14.8v absorption charge), the alternator will only provide a correct and complete charge if it’s set up with a three-phase external regulator set to the correct profile (agm, lead acid). This is the information I’m working with that makes me question whether or not an external regulator upgrade my 19SI alternators would help in getting my house bank charged faster and to a full charge. I’m not even sure what is involved to convert the 19SI for external regulation, so any information about that would be great as well!

As for my monitoring battery terminal voltage, I’m using a Victron BMV-712 monitor.

[Tony Athens]

Are you set up to monitor battery terminal voltage? If so tell me how your are doing it ( simple schematic) ? Unless you are, how would you even know what your current “charging profile” is?

[Author]

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