charging system changes. Looking for opinions and ideas

[Mischief Managed]

My boat has 8 batteries in 4 banks. I have a 3000 watt inverter/150 amp charger for the house bank, and a 3 bank 50 amp charger for the main starting, genset starting and Mathers throttle/shifters batteries. The boat has a diode-based 4 bank battery isolator between the batteries and the alternators. The boat also has combiner switches to connect any of the other three batteries to the house bank if needed.


I plan to replace the two OEM 51 amp alternators on my engine with two 90 amp Leece Nevilles and add a Balmar MC-614 external regulator. I was going to replace the diode-based isolator and combiner switches with ACRs, but a post on here got me thinking that I would be better off keeping the switches, dumping the isolator, using the alternators to charge only the house bank, and charging the other three banks with the AC powered 3 bank charger I have now. The charger would have to be powered by the inverter, but I have it running whenever we are off shore power anyway.



Seems like a pretty simple solution and would make the best use of all the hardware I already have. Any reason not to do this? I can always manually combine the batteries if I have a charger failure.

 

[kchace]

Any reason not to do it? If you run your mains every day it'll be fine. I assume you have a plan for days you aren't going to be using the mains long enough to charge the house bank? Run the charger via the generator? but then it sounds like you would manually switch to charge the house? I wonder what soured you on ACRs? Definitely get rid of the diode isolator(s).

In my case. I have the 2 house banks connected as priority charging. AC powered charger, engine alternators and solar connect directly to the house banks with ACRs between the house banks and engine start batteries since its the house banks that by far need charging the most. So whatever is running charges the house and once the house is up enough the ACRs close to top up the engine batteries. (In reality my house is usually not drawn down enough to matter - the ACRs usually close within a few minutes)

Ken

 

[Brooksie]

The diode splitters are old tech and can cause constant undercharging if your alternators don't have a sense wire bypassing them.
What about first replacing the splitters with ACR's. You can wire them right to your existing 1-2-both switches easily. You may find that is all you need to do to have a better running system. Blue Seas is very helpful if you have questions.
Certainly a high tech regulators are helpful in shortening charge time if you sit at anchor for days at a time. I'm not sure what they do for a vessel that motors every day or two. When I run my engine I am going somewhere and run it for hours so charging time is not an issue

 

[Mischief Managed]

The diode splitters are old tech and can cause constant undercharging if your alternators don't have a sense wire bypassing them.
What about first replacing the splitters with ACR's. You can wire them right to your existing 1-2-both switches easily. You may find that is all you need to do to have a better running system. Blue Seas is very helpful if you have questions.
Certainly a high tech regulators are helpful in shortening charge time if you sit at anchor for days at a time. I'm not sure what they do for a vessel that motors every day or two. When I run my engine I am going somewhere and run it for hours so charging time is not an issue

The alternators I am planning to buy don't have regulators, so I need one regardless and might as well get a great one. If I replace the isolater with ACRs (which was my original plan), It'll cost me around 600 bucks and a bunch of labor. If I just use the hardware that's already in place and working, it costs me no time and no money.

 

[Mischief Managed]

Any reason not to do it? If you run your mains every day it'll be fine. I assume you have a plan for days you aren't going to be using the mains long enough to charge the house bank? Run the charger via the generator? but then it sounds like you would manually switch to charge the house? I wonder what soured you on ACRs? Definitely get rid of the diode isolator(s).

I like ACRs, but they are not free.


The 3 non-house banks I'll be charging in the unusual manner will rarely require much of a charge and I'll only us the charger when the engines are running (via the inverter), when the genset is running, or when I'm connected to shore power.



The house bank will always be charged by the alternators when the engines are running; or by the inverter when connected to shore power or when the gen set is running.

 

[CMS]

The alternators I am planning to buy don't have regulators,

Where did you find a Leece-Neville 90A alternator that does not come with a regulator? We have to build them from raw components because LN won't sell them to dealers such as us, sans regulator.

 

[O C Diver]

I think your plan is sound. On my single engine boat I have the engine alternator and a 220 amp Leece Neville alternator with the external Balmar regulator. Engine alternator charges the engine battery and Leece Neville alternator charges the house bank.

My thoughts would be to possibly combine the two engine start batteries (or use just one) and charge it off one of your existing alternators. Put the largest Leece Neville alternator that will fit on the other engine with the Balmar regulator to charge the house bank. On my system, I added a battery switch that would allow me to combine the house and start batteries. This gives you redundancy to start the engine off of the house bank or charge both battery banks off of either alternator (in case of an alternator failure).

What is the 4th bank?

Ted

 

[rslifkin]

With my twin engines, I have 3 battery banks: start 1, start 2, house. Generator normally shares start 2 with the stbd engine, but either engine or the generator can be started from either start battery (each has a 1-2-both-off switch). House bank is independent.

For charging on shore power, the 3 bank charger feeds each bank separately. I have an ACR between each start bank and the house bank, but the ACRs have their sense wires ignition switched by their respective engine. So the ACRs don't combine when charging on shore power, they only combine a few seconds after each engine is started once they hit their voltage / time threshold to combine. They un-combine immediately at key off. In this setup, the engine alternators feed the engine batteries with the ACRs handling house charging (figuring that ensuring the start batteries are always 100% is first priority, charging house batteries comes second).

 

[Mischief Managed]

Where did you find a Leece-Neville 90A alternator that does not come with a regulator? We have to build them from raw components because LN won't sell them to dealers such as us, sans regulator.

The ad says "regulator NO" and I now realize (after your post and a little more research) that it means something other than that the alternator does not come with a regulator. I'll likely skip the external regulator now, THANKS!

 

[Mischief Managed]

I think your plan is sound. On my single engine boat I have the engine alternator and a 220 amp Leece Neville alternator with the external Balmar regulator. Engine alternator charges the engine battery and Leece Neville alternator charges the house bank.

My thoughts would be to possibly combine the two engine start batteries (or use just one) and charge it off one of your existing alternators. Put the largest Leece Neville alternator that will fit on the other engine with the Balmar regulator to charge the house bank. On my system, I added a battery switch that would allow me to combine the house and start batteries. This gives you redundancy to start the engine off of the house bank or charge both battery banks off of either alternator (in case of an alternator failure).

What is the 4th bank?

Ted

I only have one starting battery and I already have all the combining switches.



The 4th bank is for my electronic throttle/shifters which require their own battery.


AFAIK, the biggest alternator I can fit on my 3208s without a lot of fabrication is the 90 amp Leece Neville. I would do just one big alternator for the house bank if I could easily do so, but I suspect the most painless solution is the one I have described. 180 amps should be plenty for my house bank.

 

[O C Diver]

I only have one starting battery and I already have all the combining switches.



The 4th bank is for my electronic throttle/shifters which require their own battery.


AFAIK, the biggest alternator I can fit on my 3208s without a lot of fabrication is the 90 amp Leece Neville. I would do just one big alternator for the house bank if I could easily do so, but I suspect the most painless solution is the one I have described. 180 amps should be plenty for my house bank.

How big is your house bank in Amp Hours?
What chemistry (open lead acid, AGM, etc) is it?
Do you know the battery manufacturer's recommendations maximum charge rate?

What is the 3rd bank if you have 1 engine, 1 house, 1 throttle / shift battery?

Ted

 

[Mischief Managed]

How big is your house bank in Amp Hours?
What chemistry (open lead acid, AGM, etc) is it?
Do you know the battery manufacturer's recommendations maximum charge rate?

What is the 3rd bank if you have 1 engine, 1 house, 1 throttle / shift battery?

Ted

House is currently four lead acid golf cart batteries with 440 AH capacity. I will be increasing it to six GCs for 660 AH though.



The other batteries are:


main starting
generator starting
throttle/shifter


Not sure what the max charge rate is; will look.

 

[O C Diver]

House is currently four lead acid golf cart batteries with 440 AH capacity. I will be increasing it to six GCs for 660 AH though.



The other batteries are:


main starting
generator starting
throttle/shifter


Not sure what the max charge rate is; will look.

Open lead acid (golf cart batteries) generally have around a 15% of rating charge rate. Simply, your 440 AH bank probably has a charge limit recommendation of 66 amps, 99 amps for the 660 AH bank. Why is this important?

With a multi stage charger or Balmar regulator the output in the bulk stage goes to the maximum of the alternator's capacity until the battery reaches the adsorption level target voltage. In that phase the regulator holds the target voltage by reducing amperage. This is very different from the alternator regulator system you have now. The output of one alternator at 90 amps wouldn't be an issue as the boat, electronics, and accessories will be utilizing some portion of the 90 amps. However, if you have two 90 amp alternators going flat out, you could be boiling the snot out of your bank. The alternator regulators you have now produce less amps but also have a different charging profile. Basically they are designed to cover current power consumption and send some amps in to the bank. They're not designed to be a battery charger.

Too high a charge rate is potentially detrimental based on time. Charging at 20% of capacity for 30 minutes probably isn't an issue. Draining the house bank down to 60% and then changing it at 20% for hours is very different. Charging your 440 AH bank at 160 amps would be a charge rate of 36%. My uneducated but based on experience guess, would be that one 90 alternator with Balmar regulator will charge your bank twice as fast as your current 2 alternators. Two 90 amp alternators could charge your bank in the Bulk phase at 5 times your current rate.

This is my opinion. It's worth about what you paid for it. Please do your homework on the batteries you have now or will have in the future.

While the generator shouldn't need a battery charger unless it doesn't have an alternator, I would maintain it and the shift / throttle battery with a simple charger off the inverter as you had originally outlined.

Ted

 

[rslifkin]

FLA batteries have a somewhat limited acceptance rate though, so provided the charge voltage is kept reasonable, it's unlikely he'd ever see 180 amps from the pair of alternators for more than a couple of minutes. The bigger alternators just give more headroom for power usage while charging.

AGMs have a much higher charge acceptance rate, so they're more likely to need some attention paid to not feeding enough charge current to make them hot and unhappy.

 

[O C Diver]

FLA batteries have a somewhat limited acceptance rate though, so provided the charge voltage is kept reasonable, it's unlikely he'd ever see 180 amps from the pair of alternators for more than a couple of minutes. The bigger alternators just give more headroom for power usage while charging.

AGMs have a much higher charge acceptance rate, so they're more likely to need some attention paid to not feeding enough charge current to make them hot and unhappy.

I think you're mistaken.
My Leece Neville 220 amp alternator with Balmar regulator can hold 180 amp charge rate for 45 minutes on my 880 AH bank. The only reason it isn't higher is that I draw 30 plus amps underway between electronics, and all electrical boat accessories. If my bank dropped lower than 80%, the duration would be longer. Again, in the Bulk phase the alternator puts out the maximum amperage until the bank reaches the absorption target voltage. Reduction from maximum charging amperage (amps into the battery) is only what equipment on the boat is consuming.

Ted

 

[rslifkin]

180 amps into 880 amp hours is about 20.5% of capacity, so that's close to the max I'd expect a FLA bank to take for any sustained amount of time. Most will accept somewhere around 20 - 25%, although a bit less is ideal for real-world use. AGM acceptance is higher, with thin plate AGMs often accepting 100% or more.

So with his 440ah, I'd expect them to take about 110 ah at most on a sustained basis. If he upgrades to 660ah as mentioned, then it would be 165ah, or almost the full alternator output.

 

[O C Diver]

Yes, but the Balmar regulators don't reduce output based on bank size. Maybe Ok with the 660 AH bank, not with the 440 AH bank.

Ted

 

[gsholz]

You can get a 170 amp small frame alternator from Balmar (XT-170) that should be a direct fit on the 3208. For any externally regulated alternator I'd also get the alternator temp sensor to make sure extended heavy loads will not burn up the alternator.

I have two internally regulated 105 amp Leece Neville on our 3208s. I never see more than 40 amp output but I'm careful to not let the engine alternator charge into a deeply depleted 1000 amp hour house bank. The previous owner managed to burn up the factory 3208 alternators on a regular basis doing just that. I'll do some bulk charging on the generator during breakfast before I start the engines. So far, so good.

Eventually, I plan on installing a Balmar XT170 with external regulator and alternator temp sensing. But even then I'll likely throttle output to around 100 amps because the alternator is right up against the exhaust manifold on a 3208.

 

[CMS]

The ad says "regulator NO" and I now realize (after your post and a little more research) that it means something other than that the alternator does not come with a regulator. I'll likely skip the external regulator now, THANKS!

You can always convert a Leece-Neville 8MR to external regulation (see link below). Bear in mind that the internal regulators on these offer no protection for the alternator. When charging into large banks they can fry themselves as has been mentioned above. We had a custoemr chewing through 105A LN's at a rate of about 1 every 7 weeks. We replaced it with a CMI-105-ER & an MC-614 and set belt load manager to level four and installed a Balmar alternator temp sensor. That was 7 years ago....

https://marinehowto.com/external-alternator-regulation-conversion/






.

 

[CMS]

AFAIK, the biggest alternator I can fit on my 3208s without a lot of fabrication is the 90 amp Leece Neville.

LN also builds a 105A internally regulated version in the same frame. We also build a 105A already set up for external regulation and it also includes a custom billet machined pulley and the 1" to 2" fit kit.

 

[O C Diver]

You can always convert a Leece-Neville 8MR to external regulation (see link below). Bear in mind that the internal regulators on these offer no protection for the alternator. When charging into large banks they can fry themselves as has been mentioned above. We had a custoemr chewing through 105A LN's at a rate of about 1 every 7 weeks. We replaced it with a CMI-105-ER & an MC-614 and set belt load manager to level four and installed a Balmar alternator temp sensor. That was 7 years ago....

https://marinehowto.com/external-alternator-regulation-conversion/


.

CMS,
I have the large frame Leece Neville alternator that gets installed on firetrucks and EMS vehicles. The regulator mounts on top. The company I purchased it from had an aftermarket plate that replaced the regulator and gave you 2 terminals to connect an external regulator to the brushes. Are you aware of who makes that aftermarket plate?

Ted

 

[Mischief Managed]

Wow, learning so much from you folks. Thanks!



The changes I'm making are to make the boat more suitable for extended stays at anchor with as much time between genset use as possible. I also plan to add solar panels with MPPT controllers and would like to upgrade to lithium iron phosphate batteries when the FLAs die, though that's not a certainty, really depends on how the whole live-aboard plan pans out.



For now, I am going to assume that my plan of using my AC-powered battery charger for my 3 non-house battery "banks" is OK and concentrate on my alternator plans.



So if I went with two CMI-105-ER alternators and a Balmar MC-614H with alternator and battery temperature sensors, could I use the battery temperature sensor to automatically ensure that I don't put too much charge current into my FLA bank regardless of it's capacity? In other words, is it just the temperature of the batteries that's the issue when charging them too fast or is there some other parameter that I need to be concerned with? I like the idea of future-proofing my charging system, so having extra capacity seems like a good thing as long as I can control it.

 

[O C Diver]

Wow, learning so much from you folks. Thanks!



The changes I'm making are to make the boat more suitable for extended stays at anchor with as much time between genset use as possible. I also plan to add solar panels with MPPT controllers and would like to upgrade to lithium iron phosphate batteries when the FLAs die, though that's not a certainty, really depends on how the whole live-aboard plan pans out.



For now, I am going to assume that my plan of using my AC-powered battery charger for my 3 non-house battery "banks" is OK and concentrate on my alternator plans.



So if I went with two CMI-105-ER alternators and a Balmar MC-614H with alternator and battery temperature sensors, could I use the battery temperature sensor to automatically ensure that I don't put too much charge current into my FLA bank regardless of it's capacity? In other words, is it just the temperature of the batteries that's the issue when charging them too fast or is there some other parameter that I need to be concerned with? I like the idea of future-proofing my charging system, so having extra capacity seems like a good thing as long as I can control it.

If you plan to change battery chemistry, make sure the Balmar regulator will support that chemistry. They cover a number of different types, but make sure. I got a deal on mine as they were updating software to cover additional types, so mine was significantly reduced.

Given your extended hook time plans and solar, I would want a significantly larger bank to be able to harvest all solar energy when available. FLA needs to be fully recharged regularly to maintain overall capacity.

The battery temperature sensors (one for each regulator) are designed to diminish charging rate as the battery heats up and to resume after it cools down. While it is designed to protect the batteries, charging a 440 AH bank at 160 amps until the temperature sensors reduce the alternator / regulator output for the battery to cool down, isn't really a great plan.

Do you have a SOC (state of charge) gauge? If so, this should give you a real time amp charging rate going into the bank. If you're going to hook the new alternators up before changing or increasing the battery bank, you will want to watch charge rates and see what's happening with your batteries.

It's also extremely important to reevaluate battery cable sizes, especially between the alternators and the bank. You will be more than doubling the potential charge rate through those cables!

Ted

 

[Mischief Managed]

Do you have a SOC (state of charge) gauge? If so, this should give you a real time amp charging rate going into the bank. If you're going to hook the new alternators up before changing or increasing the battery bank, you will want to watch charge rates and see what's happening with your batteries.

It's also extremely important to reevaluate battery cable sizes, especially between the alternators and the bank. You will be more than doubling the potential charge rate through those cables!
Ted

I do not have an stand-alone SOC gauge, unless you count the inverter remote which shows a bar graph and battery voltage, but I was planning to add a high-quality battery monitoring system when I upgrade the whole charging system regardless.


What's the best way to manage the current going into the batteries from the alternators? Is there a device that does that?

 

[catalinajack]

Okay, this discussion has me wondering about my setup and whether I may be overcharging my house bank which is 920Ah, nominally. I have twin engines each spinning an externally-regulated 100-amp balmar alternator de-rated to 93 amps. The batteries are lead-acid Deka. The regulators are Balmar 614s. Do I need to de-rate to a lower value?

 

[rslifkin]

I wouldn't worry about de-rating further. At most, you could put 0.2C charge rate into the batteries and that's assuming you're not drawing any power at all. Realistically, your available alternator output after loads will be somewhat less, so you're not going to hurt the batteries.

What chemistry are your house batteries (AGM or flooded)?

 

[Mischief Managed]

I wouldn't worry about de-rating further. At most, you could put 0.2C charge rate into the batteries and that's assuming you're not drawing any power at all. Realistically, your available alternator output after loads will be somewhat less, so you're not going to hurt the batteries.

What chemistry are your house batteries (AGM or flooded)?

All my batteries are FLA. I have been re-reading the charging portion my Nigel Calder book, and going over my notes and the handouts from his seminar, and I have come to the conclusion that with a 660 AH FLA house bank, my target bulk charge current should be 165 amps (25% of total AH).



When you subtract my house loads while underway, and assume two small frame alternators will never be able to run at full output for long due to excess heat, I think it's safe to concur that a pair of 90 to 105 amp Leece Nevilles, with external regulation that includes temperature sensors for the alternators and the batteries, will be quite well-suited to my 165 amp target for bulk charging. I am probably over-thinking all this, but then, that's what I do...


If I do cook my batteries, I'll replace them with AGMs or lithium iron phosphates, both of which can handle much higher bulk charge rates than FLAs. I like the idea of LiFePO because I can fit 720AH of batteries in the space where I now have 660 AH, and because of deeper allowable depth of discharge, my usable AH capacity would be 576 AH, which is pretty much double what I have with lead acid technology (between 198 and 330 AH) in real-world use).

 

[O C Diver]

I do not have an stand-alone SOC gauge, unless you count the inverter remote which shows a bar graph and battery voltage, but I was planning to add a high-quality battery monitoring system when I upgrade the whole charging system regardless.


What's the best way to manage the current going into the batteries from the alternators? Is there a device that does that?

I would be prepared to only use 1 alternator until you either increase the bank size or change the chemistry. This is as simple as pulling the fuse that powers the Balmar regulator (in wiring harness).

I would move up the priority of the SOC gauge or buy an inexpensive shunt and amp meter. Is your house bank fused? As battery capacity, cable size, and charging capabilities go above 100 amps, failures can be spectacular. Really need to be able to identify quickly, what's going in or coming out.

Ted

 

[O C Diver]

Okay, this discussion has me wondering about my setup and whether I may be overcharging my house bank which is 920Ah, nominally. I have twin engines each spinning an externally-regulated 100-amp balmar alternator de-rated to 93 amps. The batteries are lead-acid Deka. The regulators are Balmar 614s. Do I need to de-rate to a lower value?

How long do they run in the bulk phase?

Ted

 

[O C Diver]

All my batteries are FLA. I have been re-reading the charging portion my Nigel Calder book, and going over my notes and the handouts from his seminar, and I have come to the conclusion that with a 660 AH FLA house bank, my target bulk charge current should be 165 amps (25% of total AH).

25% sounds high for FLA. I would find out what the battery manufacturer recommends. Certainly not saying Nigel is wrong, but would want to know what the manufacturer says. After all, they designed, built, throughly tested, and hopefully warranty them.

Ted