Battery conundrum

I’ve recently completed an extensive battery rework on my 1978-vintage Tollycraft 48. This rework has resulted in a 1250-AH house battery bank (Fullriver 6V AGMs), and a single Fullriver 8D AGM as a start battery for both main engines.

Battery charging duties while dockside is accomplished via a Blue Sea Systems multi-stage 40A “smart” charger. While I recognize this charger is marginal in capacity, I’m assured by Blue Sea that it is up to the task, and will not be overloaded in any way, even while charging such a large house battery bank. It’ll simply take a while! This charger has three charge outputs-one to the start battery, one to the house battery, and one to the generator battery.

Battery charging duties while underway are handled by two (2) Delco-Remy 105 Amp alternators. These alternators have been modified for external regulation, and are controlled via Balmar MC-614-H regulators. Balancing of regulator outputs is handled via a Balmar Centerfielder. Both alternators charge the house bank, with start battery charging duties handled via a Xantrex Echo Charger off the house bank.

I have read until my teeth bleed any and all documentation I can find on how to properly program these regulators. That programming has resulted in a setup primarily in accordance with Rod Collin’s direction in his most excellent website (https://marinehowto.com/), where he goes into extensive directions, including some video support, on how to program the Balmar 614s.

My conundrum is this. If I read Rod’s directions correctly, he is primarily concerned with making sure my batteries are not driven into “premature floatation” (a low-voltage state, 13.6V for my Fullrivers) underway. His concern is, with a partial SOC after being off-grid, not allowing the alternators to stay at a high voltage state (14.7V for my Fullriver AGMs) long enough will not return the batteries to at least the 80% SOC that seems to be the universal “sweet spot” for off-grid charging in a reasonable amount of time. So, having drunk his Kool Aide, I have dutifully dived into the advanced programming of my regulators, and forced my alternators to stay in absorption for 6 hours. When I’ve been on the hook overnight, and my battery bank is depleted, and I get underway for my next destination, all is well. My alternators put out ~160A for hours on end. And yes, they’re properly de-rated to handle belt loads, and are equipped with both alternator and battery temperature sensors as well.

BUT, on the first leg of my trip, my batteries are at 100% SOC, having been on the shore power battery charger for days at a time. So on my first leg, my alternators are humming along in absorption mode (14.7V), the batteries are fully charged, and their charge acceptance is very low (~1-2A, depending on house loads underway. And I’m sitting aboard, stewing over the fact I’m sitting on about $6K of brand new AGMs, being subjected to a 14.7V charge voltage (albeit at very low current). I simply don’t want to barbeque this new battery bank by misunderstanding the charge regimen I’ve programmed into them.

And it’s my understanding that Rod’s concern for this conundrum is small, as he’s witnessed 99.9% of AGM batteries damaged via undercharging, and virtually none from this overvoltage state.

Anybody else share my concern?

Personally, unless getting maximum charging from the engine alternators is a requirement, I'd keep the alternator voltage down a bit. Personally, I'd set their absorption to something in the 14 - 14.2 range. Yes, they'll charge slower, but it's safer for the batteries in the case where you're starting out already charged.

It may be that the net current is 1 or 2 amps but the because of house loads the actual current out of the alternators is high enough that it won't signal the regulator to begin the float stage of charging... an ammeter on the alternator output would confirm this...or just turning off all the dc loads, one other thing to check is the absorption time on the regulator.


I have lifelines and their absorption voltage is lower then what you are using.

AGM - Batteries charging rate voltage

I Agree -- 14.7-volts is to high for AGM's.

I recommend 14.4-volts for AGM long term charging.

You won't go wrong with these numbers.

Good Luck.

Alfa Mike

A quick look at the Fullriver charging profile and 14.7v charging voltate is what they recommend at 77F. Float is 13.65v at that temp. Lifeline's voltages are quite a bit less. The Fullriver recommendations are about the same as some other AGMs I've seen.


So, it all depends.

I'd agree with your plans if you are planning regular multi-day cruises anchoring out.
If you normally just anchor out for a single night, I'd reduce the 6 hours @ 14.7V volts a bit or use solar panels do the topping up while underway.

@alfamike #4

I Agree -- 14.7-volts is to high for AGM's. I recommend 14.4-volts for AGM long term charging. You won't go wrong with these numbers.

Click to expand...

Sorry, this is very bad advice.

If the mfgr. states 14.7VDC (temperature corrected, of course) they mean 14.7VDC. AGMs are particularly susceptible to partial state of charge (PSOC) issues. So not reaching the prescirbed absorption voltage and holding it until the tail current is somewhere around 0.05C (varies with battery manufacture) will chronically undercharge them and they will prematurely fail by sulfation and, to some extent, stratification.

CharlieJ said:

If the mfgr. states 14.7VDC (temperature corrected, of course) they mean 14.7VDC. AGMs are particularly susceptible to partial state of charge (PSOC) issues. So not reaching the prescirbed absorption voltage and holding it until the tail current is somewhere around 0.05C (varies with battery manufacture) will chronically undercharge them and they will prematurely fail by sulfation and, to some extent, stratification.

Click to expand...

That is true. However, if the engines aren't being relied on as the primary method of charging the batteries and they'll get topped off from other sources (such as solar), a little lower charge voltage won't hurt anything. They'll just take a little longer to reach full charge (provided they aren't dropped to float too soon).

@rslifkin #8
Sorry, I will take my advice about a very important and expensive component on a boat from the manufacturer.

It is, however, your boat.

CharlieJ said:

@rslifkin #8
Sorry, I will take my advice about a very important and expensive component on a boat from the manufacturer.

It is, however, your boat.

Click to expand...

The manufacturer advice is generally the best way to charge the things. However, they don't tell you to run them up to that voltage for hours when they're already fully charged. So if your electronics can't avoid doing that under some conditions, that's when the "lesser of 2 evils" decisions come in.

JP
I take it you do not have an inverter charger that puts out 125 to 150 amps. It would seem that at some point a high charging rate would be of benefit when at anchor to reduce genset run time and likewise load it up.

BTW that T48 is a nice vessel. What engines does she have?

You need a bigger charger. You generally don't equalize AGMs...although Lifleine has some sort of procedure. They desulfate via a hefty bulk charge....and a 40 amp charger or even those alternators still aren't likely enough. Do you know what Odyssey recommends as a charger for their AGM batteries??? One half the amp/hour bank size....in your case approx 600 amps. I have seen/heard of boats that had 40 amps chargers that could not even support the house loads while the charger was running at full capacity!!! For heaven's sakes....you spend all that money on those beautiful batteries....please get a proper charger to take care of them. 40 amps is 40 amps....Yeah Blue Seas may say they are up to the task...meaning it won't hurt them. But your batteries will suffer from sulfation in this state.

Hi Baker,

With all due respect, I'm afraid you don't grasp the issue I'm dealing with. It has ZERO to do with the size of the battery charger that is used to bring the batteries up to a 100% SOC on shore power.

Why would I care what Odyssey recommends for a bulk charge rate on their batteries? Mine are Fullriver, whose documentation states ".... The initial charge current is recommended to be set at 0.20 x C (250A in my case) in order to fully charge the batteries within a reasonable amount of time. It can be set lower; however, please be aware that charge time will increase so make sure the batteries have enough time to fully charge before being put back into service."

This is absolutely NOT my conundrum. I recognize I can't charge at an "optimum" rate, ever. But I desire to charge at an optimum VOLTAGE always. On shore power, underway, or while running my auxiliary generator. On the first leg of my trip, or the Nth leg.

You plead with me to "...For heaven's sakes....you spend all that money on those beautiful batteries....please get a proper charger to take care of them." Again, NOT the issue at hand. I'm REALLY NOT trying to elicit electrical system redesign opinions for my boat. It's about as optimized as I can afford. So things like solar, large-frame alternators, multiplexed inverter/chargers, bigger AC battery chargers, etc. are off the table. Not perfect, but all boats are a compromise.

I'm really only trying to make myself happy and glad I'm not inadvertently barbequing my battery bank, with my given Balmar regulator configuration. Honest.

Regards,

Pete

Who has an engine room temp at 77F when running? Certainly not mine. What voltage does FR recommend for at the running temp of the OP's ER? Do the installed chargers have temperature sensing for compensation?

The blue sea chargers do have a sensor for temperature compensation

alfamike said:

I Agree -- 14.7-volts is to high for AGM's.

I recommend 14.4-volts for AGM long term charging.

You won't go wrong with these numbers.

Click to expand...

Depends on battery maker. Odyssey suggests 14.7V... as apparently does FullRiver.

-Chris

jungpeter said:

Hi Baker,

With all due respect, I'm afraid you don't grasp the issue I'm dealing with. .........

I'm really only trying to make myself happy and glad I'm not inadvertently barbequing my battery bank, with my given Balmar regulator configuration. Honest.

Regards,

Pete

Click to expand...

The "issue you are dealing with" doesn't matter when your very expensive battery bank will be dead in 4 years. It would be double that(plus) with (significantly) better charging capacity. If that makes you "happy", have at it.

Good luck amigo!

PS....and to answer your question with a question....is there a way to manually control the alternator field so you could turn it on and off as you monitor the SOC of the battery bank so you do not fry your batteries in some of your scenarios?

High Wire-I put my IR temp gun directly on my house battery posts after being underway for several hours. None exceeded 72 deg F. My battery bank is located between my main engines, as low as possible in the bilge of my Tolly 48. Don't forget-here in the PNW, we operate in roughly 50 deg F water 24/7. So the entire underbody of my boat's bathed in a relatively cool thermal sink. Yup, the temp at the ceiling of my engine room is higher. But the batteries are pretty cool 24/7.

And as stated in my original posting, the chargers (the main engine alternators while underway) are temperature compensated via temperature sensors on the house batteries.

Baker-Again, with all due respect, perhaps we should agree to disagree. You continue to admonish me to "...get (significantly) better charging capacity." Due to the inherent design of the 3208 CATs (my main engines), and the resulting cramped installation in a Tolly 48 engine room, there simply isn't physical space to accommodate higher output alternators, or the attendant drive belt requirements. And the as-installed 105A Delco-Remys are WAY more capable than the 78-vintage 65A internally-regulated OEM CAT alternators. Those went away years ago under previous ownership.

If you're referring to my puny Blue Seas 40A shore power charger, I would LOVE to upgrade it. But given it's only used to put in the last residual charge deficit remaining upon plugging into shore power whenever possible, I think it'll do. It may take a while, but it gets the job done, usually within 24 hours.
And it is programmed to deliver a similar charge profile (14.7V bulk/14.7V absorb/ 13.6V float) as the Delcos.

And finally to answer your question regarding manually controlling the field of my alternators underway, the answer is yes. A published "fix" for this situation is to run a lead from the voltage regulators' temperature sensor port to a on/off switch at the dashboard. One can then artificially trip the sensor, signalling the alternator that an over-temperature state exists on the alternators, which immediately reduces the output to something like 50%. But given I'm already at way-less than full-field (SOC is 100%) upon leaving the dock at the beginning of a trip, and the combined output of the alternators is only sufficient to compensate for the running DC loads, the result is ???

And I guess if that's my only option, I guess I may post a full-on rant to Balmar, and those that promote it's virtues and programmability so highly, that (in my case) an approximately $1000 regulator/centerfielder combo requires manual operator intervention to operate "properly". Say it isn't so!!!

Regards,

Pete

jungpeter said:

High Wire-I put my IR temp gun directly on my house battery posts after being underway for several hours. None exceeded 72 deg F. My battery bank is located between my main engines, as low as possible in the bilge of my Tolly 48. Don't forget-here in the PNW, we operate in roughly 50 deg F water 24/7. So the entire underbody of my boat's bathed in a relatively cool thermal sink. Yup, the temp at the ceiling of my engine room is higher. But the batteries are pretty cool 24/7.

And as stated in my original posting, the chargers (the main engine alternators while underway) are temperature compensated via temperature sensors on the house batteries.

Baker-Again, with all due respect, perhaps we should agree to disagree. You continue to admonish me to "...get (significantly) better charging capacity." Due to the inherent design of the 3208 CATs (my main engines), and the resulting cramped installation in a Tolly 48 engine room, there simply isn't physical space to accommodate higher output alternators, or the attendant drive belt requirements. And the as-installed 105A Delco-Remys are WAY more capable than the 78-vintage 65A internally-regulated OEM CAT alternators. Those went away years ago under previous ownership.

If you're referring to my puny Blue Seas 40A shore power charger, I would LOVE to upgrade it. But given it's only used to put in the last residual charge deficit remaining upon plugging into shore power whenever possible, I think it'll do. It may take a while, but it gets the job done, usually within 24 hours.
And it is programmed to deliver a similar charge profile (14.7V bulk/14.7V absorb/ 13.6V float) as the Delcos.

And finally to answer your question regarding manually controlling the field of my alternators underway, the answer is yes. A published "fix" for this situation is to run a lead from the voltage regulators' temperature sensor port to a on/off switch at the dashboard. One can then artificially trip the sensor, signalling the alternator that an over-temperature state exists on the alternators, which immediately reduces the output to something like 50%. But given I'm already at way-less than full-field (SOC is 100%) upon leaving the dock at the beginning of a trip, and the combined output of the alternators is only sufficient to compensate for the running DC loads, the result is ???

And I guess if that's my only option, I guess I may post a full-on rant to Balmar, and those that promote it's virtues and programmability so highly, that (in my case) an approximately $1000 regulator/centerfielder combo requires manual operator intervention to operate "properly". Say it isn't so!!!

Regards,

Pete

Click to expand...

If I understand correctly, you are wanting to have the alternator regulators go immediately into 'float' charge if the battery is already full from the shore power charging when you start a journey since the are already full from shore power. Is that correct?

The Full River documentation states that the maximum absorption phase of charge is 8 hours @ 14.7 volts followed by float charge @ 13.65 for a minimum of 8 hours, so doing that absorb phase again for a long period of time after it has already been completed by the shore power charger would seem to violate that part of the specified charge regimen.

Given that, the MC-614 is pretty smart. You can set the bulk and absorption times pretty short (6 minutes) and then let it perform the calc-bulk and calc-absorb so it will back off if the batteries are already full, and go with the manufacturer's recommended voltages for those phases. If you pull the shore power plug as the first thing you do when you arrive to use the boat you can deplete the batteries a little bit and the 614's should do a good job of topping them back off and not overcharging getting to float pretty quickly.

The documentation also says that 20 hours is the maximum total charge cycle time, so your 40 amp shore power charger, if used to replenish the batteries from a 50% charge state would be unlikely to be able to meet that requirement. You didn't ask about that, but it is the case. On a 48' boat, I'm surprised it can handle dock-side 12V power needs alone if you use the boat at the dock at all.

Hi sbman,

If I understand correctly, you are wanting to have the alternator regulators go immediately into 'float' charge if the battery is already full from the shore power charging when you start a journey since the are already full from shore power. Is that correct?

Click to expand...

I believe you're correct. Upon leaving the dock on leg 1 of any trip, the batteries are at a 100% SOC after being sustained on shore power for a substantial period of time. I'd like the regulators to recognize that SOC, and thereby go to float ASAP. And not come off float until such time as the batteries' SOC degrades to some TBD level. And then go back to the bulk/absorb/float charger profile as required.

And after spending the night, where the SOC can dip to as low as 50%, for leg 2 (or leg N, depending on the particular cruise de jour), I'd like the regulators to recognize that SOC, and go into the bulk/absorb/float charge profile, again as specified by Fullriver. And it is this exact behavior that my current Balmar setup is accomplishing, every time I start up, whether or not my SOC is 100% or 50%. The only difference is the current provided via the alternator/regulator setup is 160A @50% SOC, vs ~1A at 100% SOC. But the voltage and time profiles are exactly the same.

So maybe my conundrum goes back to my lack of understanding of the chemistry of energy exchange in a Fullriver AGM. The charge profile as specified by Fullriver's specifications is programmed into my Balmar 614s. It executes that profile perfectly, every time the engines are running. And it is (in my understanding), just what the doctor has ordered to keep my large house bank happy for years to come, ASSUMING THE BATTERIES ARE DISCHARGED SIGNIFICANTLY UPON STARTUP!

But how about that same profile against a fully charged battery bank? Are AGMs damaged by high VOLTAGE, or high CURRENT? Clearly, they're damaged by high current exceeding their recommended charge acceptance rate (20%C, 250A in my case). But I ain't doing that. So, are they damaged by high VOLTAGE, with little current (~1A, in my case) for long periods of time?

Again, per Rod Collins, he claims 99.9% of AGMs fail from chronic undercharging vs overcharging. So am I trying to overthink this thing, and should I simply ignore my high voltage state upon startup, recognizing I'm dealing with 99% of my problem correctly?

Given that, the MC-614 is pretty smart. You can set the bulk and absorption times pretty short (6 minutes) and then let it perform the calc-bulk and calc-absorb so it will back off if the batteries are already full, and go with the manufacturer's recommended voltages for those phases. If you pull the shore power plug as the first thing you do when you arrive to use the boat you can deplete the batteries a little bit and the 614's should do a good job of topping them back off and not overcharging getting to float pretty quickly.

Click to expand...

Yeah, but that defeats the major benefit of the 614's, which can be programmed to NOT go to float too soon. "Premature floatation" (going to float within a few minutes) is deadly on AGMs that need recharge. And I'm going to resist to the day I die any manual intervention required to "trick" the regulators into a float condition. I spent WAY too much money to date to fall back on (IMHO) neanderthal battery management.

The documentation also says that 20 hours is the maximum total charge cycle time, so your 40 amp shore power charger, if used to replenish the batteries from a 50% charge state would be unlikely to be able to meet that requirement. You didn't ask about that, but it is the case. On a 48' boat, I'm surprised it can handle dock-side 12V power needs alone if you use the boat at the dock at all.

Click to expand...

Well, yeah, the puny Blue Seas charger can and does replenish my residual charge deficit within 24 hours. And I believe you've perhaps misinterpreted the Fullriver charging instructions a tad. Figure 1 of that sheet shows "...charging time no limit" along the abscissa. And again, yeah, even with refrigeration running 24/7, and many halogen lights still left aboard, the battery charger easily sustains the boat dockside on shore power.

Thanks for your comments and questions. Hopefully my pea-brain is absorbing this stuff, and I can learn accordingly.

Regards,

Pete

ps-in retrospect, the Wakespeed WS-500 is looking better and better. Just BOAT!

jungpeter said:

Yeah, but that defeats the major benefit of the 614's, which can be programmed to NOT go to float too soon. "Premature floatation" (going to float within a few minutes) is deadly on AGMs that need recharge. And I'm going to resist to the day I die any manual intervention required to "trick" the regulators into a float condition. I spent WAY too much money to date to fall back on (IMHO) neanderthal battery management.

Click to expand...

I don't see how that is the case. The default for the 'mandatory' bulk and absorb cycles is 18 minutes each, it moves out of those after that time period and moves into it's 'Auto' modes. The purpose of the auto-bulk and auto-absorb are to monitor the battery and not over charge it. Auto-bulk will use a voltage trigger and auto-absorb should use a current trigger.

If the batteries are already full, it needs to get to float quickly, a long absorb charge on an already full battery will be overcharging it. With the default times it would take 36+ minutes (18 for bulk, 18 for absorb plus the automodes and other cycles it goes through) to reach float. If you do that all the time starting up with full batteries, decreasing the mandatory cycle times to less might be a good idea, and that does not mean it won't stay in absorb longer when the battery is actually needing charged, it just moves to the auto modes faster.

I guess the point is the purpose of the auto-modes are to do exactly what you are wanting, stay in absorb when the batteries are empty but not stay in it long when they are full, if it isn't then something may not be right.

Typically bulk is stopped when a certain voltage threshold is reached. Then in absorb, a fixed voltage is held and when current tapers to the tail current it is moved to float, this compensates for the state of charge of the battery automatically.

Hi Sbman,

I don't see how that is the case. The default for the 'mandatory' bulk and absorb cycles is 18 minutes each, it moves out of those after that time period and moves into it's 'Auto' modes.

Click to expand...

I'm afraid you're confusing me with some of your terminology. There are no "mandatory" bulk and absorption times in the 614. There are "default" times of 18 minutes of bulk, absorption, and float charge states, assuming you select the AGL (AGM) battery type during basic programming for battery type.

And I'm sorry, I have no idea what your "...'Auto' modes" refer to. If you are referring to the Calculated Float charge stage (again with an 18 minute default time), and assuming the regulator will (in Balmar's words) "...automatically revert to the absorption charge state" at the conclusion of that state, then I think I see where you're going. But I believe you're incorrect in your terminology (confusing enough, as Balmar uses some "creative (non-industry standard) terminology in their Installation and Operation Manual as it is), and I believe Balmar calls your 'Auto modes' "Calculated Bulk" and "Calculated Absorption" and "Calculate Float" states.

The purpose of the auto-bulk and auto-absorb are to monitor the battery and not over charge it. Auto-bulk will use a voltage trigger and auto-absorb should use a current trigger.

Click to expand...

Uh, no. "Calculated bulk" and "Calculated Absorption" don't monitor anything. They are voltage and time states that are controlled by the regulator's monitoring of the regulators' field current, battery voltage, and time.

Auto-bulk will use a voltage trigger and auto-absorb should use a current trigger

Click to expand...

Well, again, the charge states don't "monitor" anything. The REGULATOR monitors battery voltage (and field current, and time) to determine if the alternator(s) should be commanded to move between bulk, absorption, and float stages. And as there is no shunt anywhere in the Balmar installation, the regulators CANNOT measure (and use) current to regulate anything.

To attempt to shorten this rhetoric, I believe what you are suggesting to me is to select the AGL (AGM) battery type in my basic Balmar 614 setup, and perhaps modify some of the battery parameters to match my Fullriver specifications, and let it go at that.

If so, we'll have to part company here, as MANY trusted sources on the WWW liken the default settings of the 614 to using a Bugatti Veyron to shop for groceries. Gross overkill, and a killer of AGM batteries, as those defaults will never allow the alternators to charge a significant battery bank in any reasonable amount of time while underway.

Regards,

Pete

The 614 can be programmed to do a 6 minute bulk then go into a calculated bulk charge which monitors the voltage as the current ramps up if need be. Then absorption charge which can also be programed for 6 minutes then go into calculated absorption ( but staying in absorption doesn't really hurt anything if you think of the wattage going into 3 to 400lbs of battery( you were saying 1 or 2 amps that's 29 (14.7v)watts versus 27 (13.5v)watts at float.. that's a lot of mass and not much power difference...my 900 a/h bank will float at 30amps

Scroll long way down to Tech Tips #6.

https://marinehowto.com/programming-a-balmar-voltage-regulator/

Exhaustive article on programming Balmer regulators.
Hope the simple fix, helps.
Rod

jungpeter said:

I'm afraid you're confusing me with some of your terminology. There are no "mandatory" bulk and absorption times in the 614. There are "default" times of 18 minutes of bulk, absorption, and float charge states, assuming you select the AGL (AGM) battery type during basic programming for battery type. And I'm sorry, I have no idea what your "...'Auto' modes" refer to. If you are referring to the Calculated Float charge stage (again with an 18 minute default time),

Click to expand...

Yes, I was referring to the calc modes. The minimum time spent in each mode is what I meant by mandatory since it won't skip those no matter how full your batteries are, and the default of 18 minutes might be excessive for a full battery.

jungpeter said:

Uh, no. "Calculated bulk" and "Calculated Absorption" don't monitor anything. They are voltage and time states that are controlled by the regulator's monitoring of the regulators' field current, battery voltage, and time.

Click to expand...

I think we are saying the same thing. The charge states are software programs in the regulator that monitor the items mentioned.

jungpeter said:

Well, again, the charge states don't "monitor" anything. The REGULATOR monitors battery voltage (and field current, and time) to determine if the alternator(s) should be commanded to move between bulk, absorption, and float stages. And as there is no shunt anywhere in the Balmar installation, the regulators CANNOT measure (and use) current to regulate anything.

Click to expand...

While this is technically true, field percentage is a good approximation of current and is part of the monitoring in the charge profile run by the regulator.

jungpeter said:

To attempt to shorten this rhetoric, I believe what you are suggesting to me is to select the AGL (AGM) battery type in my basic Balmar 614 setup, and perhaps modify some of the battery parameters to match my Fullriver specifications, and let it go at that.

If so, we'll have to part company here, as MANY trusted sources on the WWW liken the default settings of the 614 to using a Bugatti Veyron to shop for groceries. Gross overkill, and a killer of AGM batteries, as those defaults will never allow the alternators to charge a significant battery bank in any reasonable amount of time while underway.

Click to expand...

Not quite what I was saying no. I was suggesting you try modifying the time settings and then monitor a charge cycle to see if it improves the situation.

This is of particular interest to me as I am currently working with an almost identical setup with dual large frame 280 amp alternators (on FL120's with a multi groove belt conversion) with dual MC614 and a centerfielder all charging a bank of 800 AH of Northstar AGMs. Your post has prompted me to monitor their charge profile more closely and see how it's doing.

Hi Sbman,

Not quite what I was saying no. I was suggesting you try modifying the time settings and then monitor a charge cycle to see if it improves the situation.

Click to expand...

Thanks. As my install is relatively recent, and I haven't had the opportunity to sea trial it on a significant number of cruises, I'm going to do just as you suggest. I'm going to watch the whole shebang like a hawk, and modify accordingly. I only wish I wasn't using the "infinite number of monkeys" approach to my understanding!

This is of particular interest to me as I am currently working with an almost identical setup with dual large frame 280 amp alternators (on FL120's with a multi groove belt conversion) with dual MC614 and a centerfielder all charging a bank of 800 AH of Northstar AGMs. Your post has prompted me to monitor their charge profile more closely and see how it's doing.

Click to expand...

Wow, I bet you could do some pretty serious DC welding with THAT setup! Obviously very similar. For what it's worth, when and if I do this again, I'm going to take a long, hard look at the Wakespeed WS500 (Wakespeed Products). I sense several advantages over the Balmar 614/Centerfielder setup.

Firstly, no "centerfielder"-like thinghy needed to control the load sharing between alternators. Simply an ethernet cable between them. In fact (although I haven't looked too deeply into this claim), a single WS500 may be capable of controlling multiple alternators.

Secondly, the WS500 uses a shunt to monitor CURRENT into the battery, vice Balmar's choice to monitor %field. In my opinion, as %field is varying all over the place while underway as DC loads from such as refrigeration and inverter loads come and go independently, using %field to monitor SOC doesn't seem like such a great idea, at least to me. Maybe I'm picking the pepper out of the fly sh$% here, but current in/out of my battery bank seems to be REAL important, as does voltage. Monitoring current AND voltage directly, and controlling the alternators thusly, makes sense to me.

As a bit of a ding, on first glance the WS500 seems to suffer from typical tech-itis. "Hey boss, look what we can do with a single line of code". Hence perhaps too complicated for us mere mortals. And I'm waiting for some of the better-known electrical system gurus (Collins, Ellison, Cote, etc.) to weigh in with THEIR experiences with the thing. Maybe for my NEXT boat....!!!

Regards,

Pete

And to all that have kindly responded to my original posting, thank you.

It is obvious to me that, after reading as much technical literature as my brain can accommodate, and digesting the postings to date, that I am well past due to hire a competent, ABYC-certified marine electrician with DIRECT experience with such a setup as mine, and get his eyes on my installation, and provide me with professional advice.

That was my intention from the get-go, but this covid BS has complicated the matter. But no time like the present!

Regards,

Pete

roddy said:

Scroll long way down to Tech Tips #6.

https://marinehowto.com/programming-a-balmar-voltage-regulator/

Exhaustive article on programming Balmer regulators.
Hope the simple fix, helps.
Rod

Click to expand...

Bingo!! I just looked at my notes on this.

To drop an MC-614 from 14.7V to about 13.8V, with the flip of a dash switch, you just need a 1/2W 3.83K Ohm resistor tied into the MC-614's second battery battery temp terminals.

Wire the resistor into the circuit, then flip a dash switch to turn on that resistor circuit, and you now have forced float for when you leave the dock.

We need to remember that the MC-614 is a VOLTAGE regulator. It is not a current and voltage regulator. For current and voltage you'd need a Wakespeed WS500 with the additional shunt.

Field percentage really tells the regulator very little about what portion of that field energy is going into the batteries & which percentage is being used to serve house loads.

You can spend many hours tweaking FbA to suit your average house loads, and can be successful, but we find programming the reg for cruising / PSoC purposes then using a forced float switch to be much easier.

Hi Rod,

Thanks for your reply. Most learned, as always.

And roger, roger on your application of a resistor, tied to a dash switch, on the unused battery temp terminal on the 614. I think you're right on the money, given the 614 is a VOLTAGE regulator, and does NOT regulate both voltage and current, that it may be appropriate to "force to float" the alternators when the SOC is already at 100% at the start of a trip.

But I will resist to the day I die the notion that a $1000 (or so) regulator setup, advertised (and advocated by many as yourself) as the cat's meow of regulators, requires this neanderthal manual "trick" to operate properly in all conditions. I'm just stubborn enough to junk the whole mess, and install the Wakespeed solution instead.

But then again, I recognize the WS500 as having its OWN set of challenges, particularly for us DIY-ers that are not particularly computer savvy, or particularly interested in other than stress-free boating. And, as I believe the WS500 is relatively new to the market, and not particularly well reviewed and tested yet, this might be a deep dive for myself. Sigh...

And I guess unresolved to me at least, is just how badly am I beating up on my very expensive Fullriver AGM battery bank by operating at a high voltage (14.7V for both bulk and absorption) and low current (~1A) for six hours before my 614's fall to float (13.6V)? Maybe kind of a battery chemist's issue, isn't it?

Regards,

Pete

CMS said:

Bingo!! I just looked at my notes on this.

We need to remember that the MC-614 is a VOLTAGE regulator. It is not a current and voltage regulator. For current and voltage you'd need a Wakespeed WS500 with the additional shunt.

Click to expand...

Unfortunately this is right on, and any setup with the 614 is going to be a compromise. in this regard.