House Battery Bank for everything??

[Spottsville]

I say "no", not combining anything with engine start.

For me its more about being able to start the engines, under most any circumstance, than about combining or not. Our mains are started from the house batteries or the Genset or the Genset start battery. Once running they generate 12V that can also start the Genset if it's starting battery fails and charge the house.

 

[Tony Athens]

Is your engine "energize to run" ??..

That one question answers all if you have a diesel and one of the reasons you have one is "reliability" .. Just ask Rudolf if you do not understand what I am coming form..


Tony

 

[Insequent]

Anyone have thoughts on combining thruster/windlass batteries with engine start batteries?

It seems to me that they all get very little use.

In that case you have a long run of heavy gauge cable to minimise voltage drop. Better to have windlass/thruster batteries in the bow and just a short run of heavy cable. Charger wiring is still quite long but can be much lighter gauge.

 

[O C Diver]

Let me engineer this backwards. First, a big house back needs a big alternator with a smart multi stage external regulator. On my boat, I have a 220 amp Leece Neville truck alternator. That's 220 amps continuous duty above 1,000 rpm. The regulator is a multi stage Sterling that usually has my house bank back to float in a few hours. Put that setup in place of one engine alternator.

For peace of mind, you need a second independent battery that gets used regularly. There's no point having a safe battery that you don't use regularly, you won't know it lost a cell if you don't use it regularly. My vote would be to put it on the engine with the standard alternator. Only thing connected to that battery is the one engine and it's gauges. For start and bow thruster batteries I really like the red sealed Optima batteries. Then either carry a set of jumper cables or install a switch to let you start the other engine off the safe battery, or vice versa.

For the record, I thought about starting the generator off the house bank. Decided having a dedicated sealed battery for the generator already existed and made no sense to change. Mine is a normal size automotive battery and will probably last forever spinning my little 8KW generator with the Kabota engine.

One final note that doesn't pertain to the OP's situation. Many newer motors that have electronics on them will require closer to 12 volts to start them. My John Deere tier 2 engine has separate power wires that are connected to the battery in addition to the starter cables. They are adamant about adequate voltage separate from the starter to make the computer work on start up. A significantly drained house bank used as a start battery, may or may not be an issue with these types of engines.

I have one engine with 2 alternators and a separate start battery only for the engine. If the start battery fails or an alternator, I have a battery swith to tie the house and start batteries together.

Ted

 

[dhmeissner]

I would keep one dedicated batt or bank for starting the mains and gen. One 4d would be fine. All three can share. Then house bank for everything else, including windlass. Just have an option to tie house and start together for starting redundancy. An ACR for charging house when mains are running. No need to get complicated.

This is basically what I have. Except I have a manual windlass.
Bit thinking about installing thrusters, so I may have to add more capacity.

 

[SteveandZoila]

Continous duty Alternator

OC Diver
I just bought an 240Amp Leece Neville for Starboard engine to charge the House. I have not bought an multi stage regular yet. I have a deadline of cruising by June 1st on the Tn river all summer to Knoxville and back, so I can learn the boat and repair. I don't know if I have ACRs or other devices, thats why I am going to simple. I do have many other projects to keep the boat running, therefore I have limited time!

 

[O C Diver]

OC Diver
I just bought an 240Amp Leece Neville for Starboard engine to charge the House. I have not bought an multi stage regular yet. I have a deadline of cruising by June 1st on the Tn river all summer to Knoxville and back, so I can learn the boat and repair. I don't know if I have ACRs or other devices, thats why I am going to simple. I do have many other projects to keep the boat running, therefore I have limited time!

Just so you understand, an alternator is primarily a power supply for load and secondarily a modest battery charger. A multi stage shore power battery charger and a Sterling type external regulator raise the charging voltage to increase amp flow into a battery bank. If you have a battery monitor such as a Victron, you can see amp charging rate of your bank. It will show you a much smaller charge rate with the standard Leece Neville regulator. Probably under 100 amps going back into the battery. You can always add the external regulator later, but you won't get the charging rate you're expecting with the stock one.

Ted

 

[FF]

"I know the difference in design of starting vs deep cycle, but would it really be problem with that big of a bank?"

For starting the basic difference is in plate surface area.

Big surface area holds voltage up higher , for a short while , till gas covers the plate surface while cranking.

This is why starts will "come back" after a while and allow more cranking , the gas is gone.

A huge house bank has huge plate surface area and even when partly down will crank both long and hard.

The downside is if you crank the deep cycle huge bank down , it IS down and will not come back from clearing any gas.

The real question with a huge bank is recharge time and source.

About 10-15% of the banks 20 hour rate is a good charge rate , but that could be a high number for a dozen batts.

A rebuilt DN 50 with a flat belt drive might work with a smart V reg or a pair of truck alts (135A each ) with better V regulators and the bank split to allow each alt to see 1/2 the bank might work well.

If the stock V regulator is not buried in the alt which needs to be removed , replacing the V reg with an intelligent unit suitable for deep cycle recharge is the work of only a few minuets.

Both truck alts and the DN 50 have external V regs so is a snap.

You will need a SOC meter , and for safety sake I would install a low voltage alarm , to not discharge the house to the point it wont start the main engine.

 

[dhays]

Is your engine "energize to run" ??..



That one question answers all if you have a diesel and one of the reasons you have one is "reliability" .. Just ask Rudolf if you do not understand what I am coming form..





Tony

Yeah, I don't understand.

Dang I hate being so ignorant about engines.

 

[dhays]

In that case you have a long run of heavy gauge cable to minimise voltage drop. Better to have windlass/thruster batteries in the bow and just a short run of heavy cable. Charger wiring is still quite long but can be much lighter gauge.

I do have a long, heavy gauge run. I certainly could relocate some batteries to the bow to run the thruster and windlass, but then I would need to leave another battery bank in the stern for the stern thruster. I think I will stay with the long, heavy gauge run to the bow.

Downsides to combining thruster/windlass bank with starting battery? The thrusters and windlass are only operated after the engine is started, so they won't be depleting the battery so it can't start the engine. There is always the risk I suppose that one of them could have a fault which could cause a drain on the bank, but the thrusters and windlass are disconnected from the batteries by relays when they are not needed. If for some reason the start bank was dead, I could always use the house back to start the engine.

Redundancy is good, but I think that maybe I have a bit of overkill with separate start battery for the main, another for the genset, then separate thruster/windlass bank and then a house bank.

 

[Insequent]

Dhays
Ok, I did not realise or notice that you had a stern thruster as well.

You could also combine thruster bank with house bank, particularly if compatible batteries are involved. The only potential downside there would be if the house bank had a very low SOC. But then, once engines are running there should be a lot of juice available so it may not matter.

 

[Mearns]

Interesting and informative thread.

My setup and thinking is like many others - (1) separate starting batteries for main engine, (2) separate single starting battery for generator (backed by a portable charger and Honda generator 2000 which I just happen to own and need for other purposes by coincidence) and (3) separate 'house' battery bank, which runs everything else and easy to add to it as need arises.

Presently temporarily experimenting with newly-added solar panels feeding only batteries just running a ~dedicated~ line for also a newly-added (12v) refrigerator; if it proves to be an unnecessary exercise to isolated these 'refrigerator' batteries, then will add them to main 'house' bank; just want to see first who is the higher power drain, the new refrigerator or everything else, before doing so.

 

[Baker]

My boat is wired just like the OP is thinking. 5 Odyssey group 31s for EVERYTHING into one bank. A group 27 isolated genset start battery. And a set of jumper cables.

My inverter is set to cut out at 40%. Well I screwed up once and was enjoying my coffee the next day when an AC fan I have running most of the time....stopped!!! The inverter cut out. User error. I also took that opportunity to see if the engines would start at that battery state. They did. Anyway, I turned the chargerS on and the batteries were topped up in no time.

One of the things we are missing here is REALITY. HOW ARE YOU GOING TO USE YOUR BOAT?????? My set up and that of the OP is going to work 99.9999999999999 percent as well as a super complex multi bank set up. All for what???? If you plan to cruise coastally, just how much redundancy do you need???

An extreme example of this principle is in my signature. That Mainship had 2 group 27s for EVERYTHING!!!!! Start...house...thruster...windlass....no generator The thruster and windlass were at least 15 feet away. I am not advocating for such a setup. But it did surprisingly well. Obviously those poor batteries didn't last long. They had about a 3 year life expectancy in that application. The last year being a bit tenuous.

 

[Art]

I agree with Baker's post #43!


Following is copy of my post #19:


My KISS electrical arrangement!

House bank as well as twin screw engine starters: Four group 31 deep cycle LA batts in parallel. This bank also works both HD Raritan 12 v Crown toilets and a HD anchor winch.

One group 27 starter LA batt specific for gen set.

One group 27 starter LA batt isolated in separate box and kept at 100% charge as emergency. Long, heavy gauge jumpers just in case!

This simple set up works very well for us!

 

[Mearns]

Baker, you bring up a very interesting point. The boat I just bought was definitely set up for shore power and hanging around a dock; my scene is hardly ever be on shore power but among islands in the middle of Timbuktu. No wonder it was all set up so inefficiently for self-containment, such as with only TWO silly batteries for a house bank and with most appliances being major 'power pigs'. No solar whatsoever. Though I know squat about big boats, being totally new to it, was into RVs for decades, same disciplines, making it easy to see what needs to be modified.

 

[sunchaser]

Battery setups, along with various anchors can be quite successful in oh so many ways. This thread shows many battery and charging variants are successful.

But as noted by Tony Athens, dependent upon your engine's electrical needs, best to not stray too far from engine specs for voltage and amperage if your engine has a variety of electronic controls, relays and safety devices. On my engines the starter will show OK crank voltages, but not good enough for the voltage needed for relays to open or close to allow a system start. The answer - fresh start batteries and wiring, connections and fuses in tip top shape.

 

[tozz]

I would keep one dedicated batt or bank for starting the mains and gen. One 4d would be fine. All three can share. Then house bank for everything else, including windlass. Just have an option to tie house and start together for starting redundancy. An ACR for charging house when mains are running. No need to get complicated.

This is what I have on my meridian 411. Two batteries per engine and 6 2v batteries in series for 12v house bank. Separation of church and state with parallel switch in case of emergency. Separate chargers and blue sea ACRs. Magnum 2812 charger/inverter for house and blue sea P12 7522 40A charger for starters.

1. My requirements were that when on shore power or generator house bank and starters Charge with separate chargers.
2. Reduce electrical noise and crosstalk and maximize alternator output, engines are isolated.
3. When underway alternators supply current to starting batteries first then house bank.
4. All non-engine loads connected to house bank to prevent discharge of the starters
5. Generator also on the starter bank not on house.

 

[tozz]

No prob!! See post # 19.

I had to do this with my old configuration. Flipping the parallel switch at the helm is easier.

 

[Mearns]

Just learned yesterday what you two are saying, I believe. ~IF~ engine batteries fully charged (its separate smart charger say they are so after running generator), engine starts like a Swiss watch. If sharing house battery 'bank' (2 measly batteries presently) with engine batteries (after running some 12v appliances) - forget about it. Finally found the 'sharing' switch which was on 'On', it was well hidden under the steps! (6) 2vs batteries arriving today, but it does goes to show that engine batteries need to be 'maxed' and kept that way. Good point on all connections must be 'clean', adding that step to today's to-do list.

 

[foggysail]

I have several battery banks. The largest 12 @ about 430AH is used to start engines along with house keeping. But I also have a separate battery for my generator so if ever I have a problem, I can get the engines started. My solar does an excellent job keeping my bank charged.

 

[Tony Athens]

Let's try this to understand my thinking process differently............. If you have an engine that requires electrical power to keep it running (any diesel that is "energize to run", why would you want any other electrical system on the boat to be part of that, or what I typically say, "talk to it"?..

Seems totally stupid if your engine "running" to get to home or to a destination is the single most important part of your mission.. To us, maybe close to 1000 installations later with high annual hour commercial boats our forte, why would would do it that way if it was not 30+ years proven with most operators having no clue on things like that.. House system goes poo-poo but the engine(s) are still running..It that not the most important part of it all?


Tony

 

[dhays]

So Tony, you would suggest that NO other system be connected to the engine start battery? Not a genset start battery? Not a thruster battery? Windlass?

 

[Tony Athens]

DC power Distribution

The attached DC Power distribution diagram is our preferred way with a twin engine vessel & one generator. Of course there are variations but the general idea here is if one system goes poo-poo, it does not affect the other.. Key points are you always know the battery terminal voltage of each bank ( stand alone DVM's direct to the battery terminals) , you have manual capability to parallel should you need it, and it's easy to troubleshoot. Once you have a "combiner of sorts" in the system, you loose the ability to "see" or trouble shoot where the issue is.


With electronic engines, WE NEVER let the engines talk to each other except in an emergency situation and a full understanding what the current issue is. The only common thing is ONE NEG for all with redundancy across all engines.

Tony

 

[Art]

The attached DC Power distribution diagram is our preferred way with a twin engine vessel & one generator. Of course there are variations but the general idea here is if one system goes poo-poo, it does not affect the other.. Key points are you always know the battery terminal voltage of each bank ( stand alone DVM's direct to the battery terminals) , you have manual capability to parallel should you need it, and it's easy to troubleshoot. Once you have a "combiner of sorts" in the system, you loose the ability to "see" or trouble shoot where the issue is.


With electronic engines, WE NEVER let the engines talk to each other except in an emergency situation and a full understanding what the current issue is. The only common thing is ONE NEG for all with redundancy across all engines.

Tony

Tony

Thanks for sharing your interesting electric layout diagram!

I see that as an awful lot of complications... with areas that may portend breakdown.

Probably not too bad if the boat owner is an electrician wiz... which I am not!

KISS is my rule regarding all marine items; especially electricity.

 

[dhays]

The attached DC Power distribution diagram is our preferred way with a twin engine vessel & one generator. Of course there are variations but the general idea here is if one system goes poo-poo, it does not affect the other.. Key points are you always know the battery terminal voltage of each bank ( stand alone DVM's direct to the battery terminals) , you have manual capability to parallel should you need it, and it's easy to troubleshoot. Once you have a "combiner of sorts" in the system, you loose the ability to "see" or trouble shoot where the issue is.


With electronic engines, WE NEVER let the engines talk to each other except in an emergency situation and a full understanding what the current issue is. The only common thing is ONE NEG for all with redundancy across all engines.

Tony

Thanks for the diagram Tony.

Slow as I am, I think I finally understand your "energized to run" idea. I have the QSB 5.9L which would require a certain amount of electrical power to run. If I have this right, you want to be sure that the battery powering the engine has enough amperage available to keep the electronics working while the engine is running. If I understand your diagram correctly, each engine's alternator is feeding back to its own battery which would then provide plenty of power for the engine, while the engine is running.

I generally like to have all charging sources go the house bank, and then use some type of isolator be it a Duo-charger, ACR, or Echo-charger to charge the start battery. In trying to find a flaw in this I am wondering.... Say I have the thrusters/windlass/start battery all on the same bank and that bank is charged via an Echo-charger or Duo-charger. If somehow that charger fails, and we ran the engine a long time, and I was in a docking situation that required a lot of use of the thrusters, could the SOC on that battery bank drop low enough that the engine would fail to run. In this scenario, requiring lots of use of the thrusters, it would likely be a very bad time for the engine to quit.

Now, my understanding could be entirely wrong but is this the type of scenario that you are guarding against by keeping the engine battery isolated? Another question, how much voltage does an electronic engine need to keep running, vs just starting?

 

[Baker]

Thanks for the diagram Tony.

Slow as I am, I think I finally understand your "energized to run" idea.

Dave, another thing he is guarding against is if both engines are on the same electrical bus, like mine, then the electronics will be potentially sharing information or even "confusing" information. IOW, each engine and its data is not isolated to that engine only. There is some "cross contamination" of data. That is the way I am reading his post.

With that said, mechanical engines like mine(330B Diamonds) are "energized to run". They need power to keep the fuel solenoid open. If power is lost, the engine quits. So his diagram is not just for common rail electronic engines. In my installation, if my entire house/start bank fried, my engines would not start or would not remain running. I do believe I could repair the issue in the field though Since I have batteries that are isolated.

 

[dhays]

Thanks Baker. I am learning more bits and pieces all the time.

 

[stubones99]

What about an ESM - Super Cap starter battery for engine starts?

Maxwell Technologies Engine Starting Module

The cool thing about ESM's are the charging connections could come from your house batteries, and the start connections go to the engine they start.

They are designed to run in OTR trucks and can save lots of weight over having two big 4D batteries on big diesel engines. I saw something in the marine press a couple of years ago, and posted it here and think no one responded.

Preemptively, no, I don't know anyone with them in a boat, I have no affiliation with the company or anyone selling them, and don't know the $$ yet.

Advantages:
Light weight - 17-18 lbs per ESM.
Long life - 4+ years warranty million or so charge / discharge cycles.
fast recharge time (15 minutes)
12v or 24v with one unit.
no water/acid problems (none at all)
great high / low temp operation
shock / vibration resistant.
small size (13" x 7" x 10")

 

[mramoo]

I think one could buy a lot of batteries for $1400.

 

[mbevins]

I think one could buy a lot of batteries for $1400.

Actually no.... Pretty sure my 4 Victron AGM s were in that price range.
Three for the house, one dedicated to the engines.