External 3-stage Regulator, or a Controller???

[StringBimini]

I am considering a repower on my boat, with a new diesel engine, and with that, a new alternator. At the same time, I am upgrading my battery bank(s), with the house bank to be configured with two parallel lines of two 6V batteries in series. In other words, four 6 V batteries total, but arranged in parallel/series to look like a single 12V bank, about 400 amp-hours storage at 12 V. It will either be conventional lead-acid, or agm type battery technology. I will also have a dedicated starting battery, either lead-acid, or agm (haven't decided yet). Point is, I may have different technology batteries on my boat. I am also designing for a potential future dedicated battery for a windlass. So, potentially three charging loops, and different battery technologies.

Now my questions:

1. I want to go with a 100 amp alternator, and some sort of external regulator, or controller, off of the engine alternator. However, I don't know which one is best, or what brands to consider. Any suggestions?

2. The engine mfg has suggested either a Balmar (model 614) external regulator, or his preference, an Adverc Controller. An external regulator has capability for 3-stage charging, however I think it can only do one charging scenario, i.e. it doesn't have multiple leads to charge each battery with a different 3-stage regimen, optimized for different battery type, correct? Are there smart regulators capable of charging 2 or more separate battery banks, with different charging regimens?

3. The Adverc controller looks like it can handle at least 2 different (3-stage) charging programs (to accommodate two different battery types). With this unit, the internal regulator is left in the alternator, and the controller then conditions the regulated power from the alternator. Is this a good way of doing it, or is external regulation the way to go? Give me the pros/cons if you would.

4. I must always ask this one: Am I overthinking it?? Could a single 3-stage charging program (regulator) to all battery types is okay? I recognize that I may also need a device that preferentially charges the starter battery, then secondarily the house bank.

I also had a question about shore-power battery charger, but I will handle that in a separate post.

Thanks...SB

[cwyckham]

I think you're making it too complicated. Choose one battery type for all batteries and your life gets a whole lot easier and cheaper. Now find a way to have only two banks instead of three unless you have a really unusual setup. Finally, run all charging sources to the house bank and use an echo charger for the start battery.

Simple is good. Many of these points are discussed in great detail by wise sailors on the archives. I've learned a lot from them.

[phorvati]

He has a single bank, its just how the golfcart batteries are setup. One type for house, and one type for starting.
You're not over thinking it. You're investing a lot of money in this, and it should setup properly.
I am sure everyone will have their own opinion on how stuff should be installed. I've gone through this back in 2004 and its an ongoing process. And i can only share what Ive learned and my dos and don'ts.
One house bank is how I set it up, and I followed Calder's book like a bible during my installation.
Go with AGMs unless you like acid burns and hydrogen etc. AGMs are more $$$ but maintenance free no acid, no hydrogen, no equalization.
Starting battery can be different type, but should be charged via echo charger or similar auxiliary charging capability. I take mine off of Solar charge controller. I am assuming your starting battery is separated from house. Mine is completely separate fused and + only goes to the starter. I have a small charging wire from solar controller to starting battery.
For regulator, Balmar is ok. I have xanterx. You need 3 stage regulator, and you need a bank monitor like Link 10. Different batteries have different float/absorption/bulk voltage settings and regulator should be programmable for your battery type. 2 programmable settings sounds ok. If you go with acid house bank, it would be nice to have equalization setting on a regulator so that you can equalize.
Alternators produce tremendous amounts of heat. I was much happier having regulator external. Keep it out of the engine room altogether. I am even looking into having external rectifier(diode bridge).

Are you following a guide or a book? I would highly recommend Calder.

[mitiempo]

I agree with cwyckham - keep it simple.

I would route all charging to the house bank as it will need it the most. A dedicated start battery will use less than 1 AH for engine starting. I would charge it with an Echo Charge.

For the future windlass I would run the proper cabling forward from the house bank with appropriate fusing. If you install a forward battery you still have to charge it so the cables will be large gauge anyway and it saves maintenance on an extra battery.

I would go with the Balmar external reg - The MC-614 you mentioned is a good choice. It allows you to cut back the alt output which will extend the alts life if you go with AGM batteries.

I personally would go with good flooded batteries. They are more forgiving than AGM batteries and should last as long. In any case I would keep all batteries the same technology.

You might find this interesting concerning battery type: AGM Batteries - Making The Choice - SailboatOwners.com

[btrayfors]

+1 ... what mitiempo said.

Minor exception: charging regimes for AGMs and flooded batteries (they're both lead-acid, as are gels) are almost identical and, for practical purposes, are interchangeable.

I'd still go with flooded batteries unless you have a very good reason for going with AGMs.

Bill

[phorvati]

Originally Posted by mitiempo

I personally would go with good flooded batteries. They are more forgiving than AGM batteries and should last as long. In any case I would keep all batteries the same technology.

Not sure how are led acid more forgiving? With Lead acid, you can never leave them in subzero temperatures. And on a sunny day(I have solar panels), or during motoring they were boiling and overheating due to overcharging, unless I turned the lights on to keep the voltage down. I can leave AGMs in sub freezing temperatures w/o a problem. With AGMs, solar panels drive the system voltage up, sometimes to 16V and they stay cool, no overheating during bulk and other charging cycles. AGM have almost no internal resistance, your charging losses are a fraction of those with lead acid. The fact that they don't heat up tells me that my charging is more efficient. I've lived on lead acid trojans for 5 years, and now on AGM trojans so far 2+ years. I have not reached 300+ cycles yet on AGMs so only time will tell. But my living habits and consumption is similar. So far, 2 years into it, I am pro AGM. If they run flat after 3 years, I'll be disappointed and go back to Lead acid.

[DotDun]

Originally Posted by phorvati

Not sure how are led acid more forgiving? With Lead acid, you can never leave them in subzero temperatures. And on a sunny day(I have solar panels), or during motoring they were boiling and overheating due to overcharging, unless I turned the lights on to keep the voltage down. I can leave AGMs in sub freezing temperatures w/o a problem. With AGMs, solar panels drive the system voltage up, sometimes to 16V and they stay cool, no overheating during bulk and other charging cycles. AGM have almost no internal resistance, your charging losses are a fraction of those with lead acid. The fact that they don't heat up tells me that my charging is more efficient. I've lived on lead acid trojans for 5 years, and now on AGM trojans so far 2+ years. I have not reached 300+ cycles yet on AGMs so only time will tell. But my living habits and consumption is similar. So far, 2 years into it, I am pro AGM. If they run flat after 3 years, I'll be disappointed and go back to Lead acid.

IMO, if you see boiling and overheating you either have bad batteries or a bad regulator. Your solar should not reach 16v nor should your engine alternator.

[mitiempo]

I agree, the batteries should never see voltages that high. 14.3 is the bulk/absorption voltage for AGM batteries. It sounds like you are running a panel without a controller or if there is one it is either set wrong or it has failed. No type of battery likes a voltage that high.

As far as flooded being more forgiving the following is from Lifeline, the only company that recommends equalizing AGM batteries:

[mjwarner]

A couple of other things to consider, and you may have already thought of them, but first you need to remember that a 100 amp alternator doesn't mean that the output will be 100 amps... it will be somewhat less than that. Second, don't get the biggest alternator you can, or that you think you can use, size the alternator to the size of the engine you are installing. Too big of an alternator will pull on your engine power (the horsepower) too much. Not good for it at all. If you go with anything over 80amps, use a serpentine or dual belts too. I do agree with the others in that you should keep all your batteries of the same type, makes life so much simpler.

[mitiempo]

The reason I suggested the Balmar MC-614 regulator is that it can be dialed back for longer alt life. AGM batteries will take almost anything you can feed them if in bulk charging mode. Alternators are not designed to run at max output for long periods of time. A 100 amp alt dialed back to 70 or so will last a lot longer than a 70 amp alt running flat out as is likely to happen with AGM batteries. An alt temp sensor would be essential as well in my opinion, with either a large flooded bank or especially with AGM batteries.
A serpentine belt is a good idea.

[Maine Sail]

Originally Posted by phorvati

Not sure how are led acid more forgiving? With Lead acid, you can never leave them in subzero temperatures.

AGM, GEL and WET batteries are all "lead acid" the difference is whether the electrolyte is absorbed into a glass mat, mixed with silica to form a Jello like GEL or wet liquid acid.

Considering I lived in Fairbanks, AK and all we had back then was WET batteries the statement that you can "never" leave them in sub zero temps is an entertaining one.. The batts on our boats reside all winter in Maine and are fine, and have been for over 25 years. If fully charged a wet cell battery will not freeze until about -72F.

Originally Posted by phorvati

And on a sunny day(I have solar panels), or during motoring they were boiling and overheating due to overcharging, unless I turned the lights on to keep the voltage down.

You really needed to address your voltage issue..

Originally Posted by phorvati

I can leave AGMs in sub freezing temperatures w/o a problem.

We do it all the time in Maine with regular old wet cells and did it in cars, tractors, planes, snowmobiles etc. etc. all time, even in Fairbanks, where temps dipped to -50F or worse. They don't have much cranking ability at those temps but they survive just fine. the only thing to be mindful of with wets is that you move the electrolyte every now and then to prevent stratification.

Originally Posted by phorvati

With AGMs, solar panels drive the system voltage up, sometimes to 16V and they stay cool, no overheating during bulk and other charging cycles.

That's a GREAT WAY to ruin expensive AGM batteries! You need a charge controller that works and you really should address your over charging issue or you'll ruin your AGM's..

Originally Posted by phorvati

AGM have almost no internal resistance, your charging losses are a fraction of those with lead acid. The fact that they don't heat up tells me that my charging is more efficient. I've lived on lead acid trojans for 5 years, and now on AGM trojans so far 2+ years.

As long as we're referencing Trojan here's a direct statement from them:

"Generally, gel and AGM batteries have about 20% less capacity, cost about two times more, and have a shorter cycle life than comparable flooded lead acid batteries. Gel batteries are more suitable for deep cycling applications whereas AGM batteries are more for light cycling and engine-starting applications."

Originally Posted by phorvati

I have not reached 300+ cycles yet on AGMs so only time will tell. But my living habits and consumption is similar. So far, 2 years into it, I am pro AGM. If they run flat after 3 years, I'll be disappointed and go back to Lead acid.

The fact that you got five years out of wet Trojans, while over charging in the range of 16V, is a testament to the durability of wets. If you want to see 3 or 4 years you'd be very well served to get your over charging problems fixed. When you charge AGM's to gassing voltages, 16V is way beyond that, they still vent. Unlike wets when AGM's vent you have no way to replenish the lost electrolyte. Trojan AGM's are not like Lifeline AGM batteries as the Trojans can not be equalized, which is what you are doing at 16+ volts.. I am simply amazed they've lasted 2 years...

The max charging voltage for Trojan brand AGM batteries is 14.7V. You are well in excess of that at 16V and even beyond their max 15.5V equalizing voltage for their wet cells.. The recommend a "range" for absorption voltage of Trojan AGM's is 14.1 to 14.7V. There is no conditioning or equalizing voltage for Trojan AGM's so 14.7V at 77F, temp corrected above and below, is the max they want to see.....


From Trojan Re: AGM's.:

"Do not install or charge batteries in a sealed or non-ventilated compartment.

Constant under or overcharging will damage the battery and shorten its life as with any battery.

Charging temperature compensation
.028 VPC for every 10°F (5.55°C) above or below 77°F (25°C) (add .028 VPC for every 10°F (5.55°C) below 77°F and subtract .028 VPC for every 10°C above 77°F)."




What the above means is that in order to be charging Trojan AGM's at 16V you'd need to be doing so when the physical battery temp was about 0F..

[phorvati]

Regulator has an adjustable float. If I turn it to highest setting, voltage can get as high as 16V. But to me heating is a sign of damage. I am just comparing wet cell and AGMs as far as maintenance and being forgiving. Less heating means, less internal resistance and less loss, less chance to damage it if you overcharge them. Now that I have AGMs, and I had them for a while, I'm very pleased. In my experience they are more forgiving, and easier, and worth the higher price.

As far as equalization on the wet cell, you can equalize higher then 15 or so, you just have to monitor the temperature. Temperature is and indication of damage. With wet cell that temperature rises quickly as you increase equalization voltage. And with time, the surface gets so oxidized that you need to bump up the voltage, but because their higher internal resistance, it leads to overheating and boiling. That's when damage occurs.

[DeepFrz]

Originally Posted by phorvati View Post
Not sure how are led acid more forgiving? With Lead acid, you can never leave them in subzero temperatures.

Whoa, I better warn all those folks living in NA that the batteries in their cars are in extreme risk.

I have seen a battery that had very little power in low temps. I could just hear the solenoid activate. It was -50 deg. F and I took the battery out of my car and set it on a radiator for a couple of hrs. Meanwhile I plugged the block heater in and covered the car with a tarp. Took a while to get the front wheels to turn after I got the car started. That was a while ago though...I haven't seen temps like that in a long time. About -35 c is about the lowest I have seen in a few yrs.