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1/BOTH/2/OFF Switches Thoughts & Musings

Discussion in 'Musings With Maine Sail' started by Maine Sail, Jan 31, 2012. Add this thread to a FAQ

  1. pateco

    pateco

    Joined Aug 12, 2014
    989 posts, 100 likes
    Hunter 31 (1983)
    US Pompano Beach FL


  2. mitiempo

    mitiempo

    Joined Sep 28, 2008
    917 posts, 7 likes
    Canadian Sailcraft CS27
    Ca Victoria B.C.


  3. BayMan

    BayMan

    Joined Sep 12, 2012
    200 posts, 10 likes
    Hunter 450
    US Unspecified
    I've read MS's post twice (excellent as always) but haven't yet gone through all the later discussions. A couple questions.
    1) you mention that this works well on a smaller boat/house bank- my house bank is now 2 6v batteries wired together but that is going to probably grow to 4- still ok?
    2) you recommend the ACR or Echo- I read that correctly, didn't I? One but not both are needed?
    3) of the two, what do you suggest? The ACR seems better choice for me.
    4 ) what happens to my existing battery charging equipment after I install these new items? Remove? (Not the alternator obviously )
    5) is this really a DIY job for someone who is handy but not nearly your level of skill with marine electronics?
    6) I have plans for solar and it seems that wiring it to the House bank simplifies things. Is there anything else to be done at the same time to be ready for later solar.
     


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  4. pateco

    pateco

    Joined Aug 12, 2014
    989 posts, 100 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    I have the same question. Currently I have two Group24 pseudo deep cycle located in the starboard lazzerette. Planning on adding an ACR, changing the two group24 to two 6V golf cart for house bank in the same location, and a new Group24 Pseudo for the start battery in a location closer to the engine on the port side of the boat. Wondering how to rewire mains powered charging system to handle this?

    Any diagrams would be greatly appreciated.
     


  5. mitiempo

    mitiempo

    Joined Sep 28, 2008
    917 posts, 7 likes
    Canadian Sailcraft CS27
    Ca Victoria B.C.
    All charge sources should be wired direct to the house bank and fused.
     


  6. pateco

    pateco

    Joined Aug 12, 2014
    989 posts, 100 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    Another quick question. What is the difference between 1or 2 gauge marine and 1or 2 gauge welding wire?

    There are websites selling welding wire for marine use, and it does say it is chemical and oil resistant.
     


  7. woodster

    woodster

    Joined Sep 15, 2009
    6,237 posts, 258 likes
    S2 9.2a
    US Fairhope Al
    that is the insulation not the wire ....the wire is not tinned just fine strand copper and will wick water like a sponge and then corrode like crazy
     


  8. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,038 posts, 193 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME
    UL 1426 Marine battery cable is tinned wire and most welding cable is not. Most welding cable is not suitable for marine use due to the jacket being a more permeable EPDM. EPDM is prone to degradation from bilge oils, chemicals etc.. etc..... If you can find a 105C UL rated welding cable with oil resistant/suitable jacket what you will usually find is that it costs more than a UL1426 105C marine wire..
     


  9. Stu Jackson

    Stu Jackson

    Joined Feb 26, 2004
    18,973 posts, 241 likes
    Catalina 34
    US C34 San Francisco
    You simply wire the shorepower charger to the house bank, too. IIRC, this is covered if you go back and read the thread.
     


  10. varigging

    varigging

    Joined Dec 7, 2013
    23 posts, 0 likes
    Hunter 376
    US Lancaster Va
    In reading this thread there is a lot of great information that I have tried to follow during my most recent instillation. I still have a few questions if I may. Sorry for the length but I tried to provide as much detail as possible.

    I just completed the first phase of a complete power upgrade for our Hunter 376. The original set up was one group 24 lead acid starting battery and two lead acid group 24 house batteries.

    This upgrade included the addition of five (5) AGM batteries (GPL31XT), a new 90 amp charger, breakers, smart gauge, and 2/0 ga. wiring and one group 27 lead acid starting battery. As seen in the photo of bank 1 each battery has it’s own breaker and is wired to a + and - buss. There are two banks with there own buss (Bank 1 - three batteries, Bank 2 - two batteries) The buses are connected to an A/B/Both/Off switch so that they can be bridged together to make one complete 625ah bank. This is done for redundancy as well as the ability to be able to isolate each part of the system. The 90 amp charger has three leads (only two are being used). The charger is used to charge the House banks only and each feed, to each of the banks is also independently fused. There is also a lead acid starting battery for the engine and genset wired to its own on/off switch.


    I am now considering the rest of the system details. I originally was going to run an echo charger to charge the starting battery, as the 90 charger has a lead connected to each of the house busses and nothing connected to the starting battery since it is not the same profile. I didn’t want to cook it. I am now wondering if I should just remove the starting battery all together and install another AGM and connect it to the second bank to balance the battery banks to three batteries in each bank for a total of 750ah. I would then use the house bank to start the engine / generator.


    I also have an ACR that was stock that I have kept in place. This is so that the alternator can charge the starting battery and the house at the same time. Since the house batteries are so much larger then the start, I am not sure that it will do much good. I thought about removing the ACR and just running the alternator to the start battery. This of corse would not be an issue if I convert to all house batteries and remove the Start battery all together. I am running the stock alternator on a Yanmar 3JH2E (55 amp). Since we only run the engine for short amounts of time ( less then an hour) to get out to the river to sail, I don’t see gaining much charge for the house batteries anyway. This is why I have not upgraded the stock alternator. I am wondering if I should go with an external regulator though to limit any possible damage due to the larger house bank even if I get rid of the start battery?

    We have 30 amp service at our dock that supplies power to the charger to keep the AGMs topped off. We have an onboard 6.5kw diesel generator that I can run to keep the batteries topped off while on the hook. We usually only go over night for a few days at a time so managing the AGMs back to 100% is not an issue. It is only my wife and I and my largest draw is the refer. Everything else has been converted to LED. We also have a Gantz 55watt solar panel and regulator that is used to keep the start battery topped off while we have the power disconnected. I am looking at installing more solar (325 watts) in the future to help get the AGM’s to 100% during the day.


    So I guess my questions are these:

    1. Should I remove the lead acid battery and install another AGM to the house system? If this is the case I need to do this now so that all my batteries are of the same series / age. Or is it better to have the redundancy of a stand alone start battery even thought the house banks are not the same size?
    2. Should I install an external regulator to the Alternator?
    3. Should I just remove the ACR all together and have the alternator charge the start battery if I elect to keep it or charge just the house battery and use an echo charger?
    4. If I keep the Lead acid start battery, should I run the Echo charger from the house bank or can it be run off of the third lead of the charger?
    5. Am I missing something so blatant it has eluded me?
     

    Attached Files:



  11. Stu Jackson

    Stu Jackson

    Joined Feb 26, 2004
    18,973 posts, 241 likes
    Catalina 34
    US C34 San Francisco
    Please, take a DEEP breath.

    You have complicated what is essentially a simple issue.

    These are the basic articles about house & start/reserve banks, and one is from Maine Sail, which it appears you've already read. Try reading them again.

    Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

    This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
    http://forums.catalina.sailboatowners.com/showthread.php?t=137615

    That is this very thread. Don't click on it! :)

    1. Make your house bank as large as you can and stop separating them. You are doing neither partial house bank any favors, since the largest bank you can make will work better and last longer because the % of discharge will be reduced with the same daily load. You are fortunate enough to have an ample house bank capacity, meaning you have room for a LOT of batteries.

    2. No. Your Hitachi alternator has a built-in temperature sensor. It won't help. Here's why: Hitachi Alternators 101 http://forums.catalina.sailboatowners.com/showthread.php?t=166123 This comes up so often on other boating forums...

    3. No. Keep the ACR. Gang all of your house batteries together and use the ACR to charge the start/reserve bank. NEVER charge the start bank first, it rarely needs much since starting an engine uses all of a couple of amp hours. This is basic to all the discussions you've read.

    4. No. Forget the echo charger, you already have the ACR. Take all of the secondary leads from your shorepower charger off the secondary banks. Run only ONE lead from the shorepower charger to the BIG house bank and the ACR will take care of the start bank.

    5. See #4. Hope this helps. KISS.

    BTW, Maine Sail is busy out working on boats today as he reported earlier, so I've taken this opportunity to try to help.

    You have a very good setup with physical attributes that most folks don't have: space for a healthy house bank. With a fridge running, most folks use 100 ah per day as the daily load. You should do just fine, even without using the generator for at least two days IF you combine all your house batteries into ONE bank. Why bother switching? Your concern about redundancy is repeated often. If one battery craps out, just un-wire it from the bank. Rewire your 1-2-B switch for House Bank #1, start bank #2. You're done.
     


  12. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,038 posts, 193 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME
    That is a hefty bank/s of AGM batteries @ 625Ah's. You will want to be sure your charge voltages are accurate 14.4V & 13.4V and that all charge sources are temp compensated..

    Issue #1 = Breakers

    AGM batteries have enormous short circuit potential, upwards of 5000A + per battery, and breakers generally do not meet the recommended AIC (amperage interrupt current rating). You also do not need nor want one breaker per battery as they are redundant, increase the failure points in the system, and also lead to more voltage drop. In a dead short breakers can literally weld shut if they don't meet the AIC rating. Class T, ANL or MRBF fuses are the proper devices for main battery over-current protection.

    Issue #2 - No need for this switch or two banks.

    The most efficient way to wire a bank like this is contiguously as one large bank. This avoids voltage drop issues, keeps the batteries better balanced and leads to considerably longer life when the batteries are charged and discharged as a larger bank. There are a myriad of reasons you do not want two house banks. You already have a redundant / emergency bank there is no need for three nor all the extra connections, switches etc...


    You already have redundancy in the AUX / START battery. Splitting the house bank is an unwise choice especially with very expensive AGM batteries.

    The only way to truly "isolate" a bad battery would be to have an ON/OFF for each battery. If you short a battery on Bank 2 the 10V or 8V battery is still in parallel with the other 12V battery and can still thermally run away. If you short a battery on Bank 1 the 10V or 8V battery is still in parallel with the other two 12V batteries and can still run away.

    In a scenario such as this you still need to manually identify the bad battery with a temp gun or isolated voltage readings anyway. By the time you've figured it out a few turns with a 14mm wrench and the bad battery is out of the circuit and you can continue on. In the real scheme of things the dual banks serve no redundancy purpose. The start battery can be switched in to maintain house loads while you identify the issue and take that battery off line. If you never allow your bank to drop below 12.2V then this is such a rarity that it is barely worth worrying about. Best course of action is to leave two "stubby wrenches" sized for the battery terminals mounted close to the batteries. if you never allow your bank to drop below 12.2V then there is minimal possibility you'd ever need that redundancy and your house bank will have a nice loong life and your start/aux/reserve bank will get really bored.


    The charger only needs to feed one bank, the house bank, and the ACR can charge the AUX bank. All those extra wires and fuses are simply unnecessary.


    For a boat like your a simple three ON/OFF switch configuration would be ideal and you would not be carrying around "isolated dead lead" that could never be called on in an emergency.. Share the Start/AUX battery between the engine and the genset, for starting both, as well as allowing it to serve house purposes through an emergency paralleling switch. The engine and genset draw so little power for starting that a simple G-31 battery is a perfect match for both and if a deep-cycle is used it can also serve as emergency house loads..


    A flooded battery will not be damaged by using charge voltages for Lifeline AGM's. You already have an ACR and it is a great choice....

    You won't unless you believe all the wives tales you read on the net......

    No... One battery bank, contiguously wired, for house and one bank for starting. The banks should have the ability to be selected to serve house and starting duties while also being able to fully isolate the other bank. The three On/Off or 1/2/B with extra ON/OFF does this.



    The ACR is an ideal choice for this application because it will allow the genset alternator, in conjunction with the 90A charger, to also feed the house bank during bulk charging. The Echo charger can't do this.

    **ALL CHARGE SOURCES, OTHER THAN THE GENSET ALT, FEED TO THE HOUSE BANK INCLUDING ENGINE ALT**


    Do not remove the ACR it is ideal for your configuration. You however DO NOT want to feed the main engine alt to the start battery, it should directly feed the house bank.

    Again stick with the 625Ah house bank and keep a single starting battery for the genset and engine.

    It won't do much other than get hot and pump out 20-30A at best. With AGM batteries they deserve a better alternator and regulator but if this is the only time it gets used you can squeak by.

    Putting an external regulator on that alt is like putting a prom dress on a pig. You can dress it up but it's still a pig. You're still not going to get much out of it and the expenditure would not be worthy of any decent quantifiable gains.

    In order to be kind to your expensive AGM batteries it is not the amperage we are concerned about it is the VOLTAGE. The voltage of the charger needs to be carefully set to match the recommendations of Lifeline. The best profile is 14.4V and 13.4V TEMP COMPENSATED. If your charger does not have an on-battery temperature probe it is not smart enough for Lifeline AGM batteries.

    It is critical for AGM batteries to get back to 100% SOC as often as is possible for optimal life. Lifeline's also need to be equalized if regularly used in a PSOC environment. Keeping the batteries "topped off" however requires TIME. Your max charge rate with the charger is 90A or 0.14C (14% of Ah capacity). Lifeline recommends a bare minimum of .2C or 20% of Ah capacity in charge current. At a 90A charge rate you are looking at well in excess of 6.5 hours to go from 50% SOC to 100% SOC, and this is with healthy batteries. Unless you plan to run the genset for hours & hours & hours "topped off" is pretty much Disney fairy tale and where solar can help. This is also why keeping the ACR is beneficial because now your small genset alt (if it has one) can add another 20-30A to the 90A charger in bulk.

    If this is the case 625Ah of AGM is a huge expenditure when not taking advantage of the fast acceptance benefits.. I might suggest taking one of the 31XT's and use it as the new start battery and continue on with a 500Ah house bank.

    Do you actually know your daily consumption in Ah's? This would have been the optimal starting point in the system design.


    Keep two banks HOUSE and START. Remove one 31XT from the house bank and make it your new start bank. Wire the other four 31XT;s as your new house bank with no switch between any of them...
    Not on that alt there will be little to no benefit. It is far to anemic to charge even 200Ah's of AGM's let alone 625 Ah's..

    Se answers above..
    If you stick with a 625Ah house bank just use the ACR to charge the flooded battery. All charge sources except the genset alt go to house.
    Might have been a good idea to ask some of these questions before committing...:wink3:
     


  13. varigging

    varigging

    Joined Dec 7, 2013
    23 posts, 0 likes
    Hunter 376
    US Lancaster Va
    Stu,
    Thank you very much for the fast reply. You pretty much confirmed what I was thinking. I think I am still going to add an Echo charger because unless the boat is running and the ACR ( actually a stock VSR) is in connect mode there is no real charging of the reserve battery. Since we don't usually run the engine for that long of time, I worry that the reserve battery will never be brought up to a full charge, if the boat sits for a few weeks at any given time.

    I am headed off now to pick up a few supplies to make the necessary wiring changes (larger Buss bar to keep the lands / labeling clean and wire, etc). I should be able to put this to bed by tomorrow night.

    The next thing I guess from your reply is to address the alternator. In reading your other post on the topic it looks that the stock Hitachi is crap. I just figured since I wasn't really using it to charge the batteries to capacity that the stock one would work. Do you have any suggestions on brands and size for this size battery bank (625ah) ? I was figuring that I might as well go with a 140ah and external regulator if i was going to do the swap out. Thank again.
     


  14. pateco

    pateco

    Joined Aug 12, 2014
    989 posts, 100 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    I have the charger below. it is currently wired to two 12v Group 24 pseudo deep cycle batteries connected a 1-2-All switch. I am considering switching to two 6v golf cart for main bank, and relocating and using one of the Group 24s as a separate start battery. If I added an ACR, do you think this charger would be sufficient for my new banks?
    2016-04-26 19.40.24.jpg
     


  15. Stu Jackson

    Stu Jackson

    Joined Feb 26, 2004
    18,973 posts, 241 likes
    Catalina 34
    US C34 San Francisco
    You're very welcome.

    You discussion here is just plain wrong. The ACR is a relay that closes when charging sources are present. The echo charger does the same thing but limits current to 15A. In neither case does your start bank use more than a few ah, if that, to start the engine. You will have many, many, many restarts even if you NEVER recharge the start bank. 2 ah to start the engine with a 100 ah start bank, using 50% or 50 usable ah is 25 starts!!! Don't bother. Really.

    What are ACRs, Combiners & Echo Chargers? (by Maine Sail)
    http://forums.catalina.sailboatowners.com/showthread.php?p=742417
     


  16. woodster

    woodster

    Joined Sep 15, 2009
    6,237 posts, 258 likes
    S2 9.2a
    US Fairhope Al
    that's not much for that size bank...... you should be at 20% charge capacity ei 100 amp bat + 20 amp charger ect ect
     


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  17. varigging

    varigging

    Joined Dec 7, 2013
    23 posts, 0 likes
    Hunter 376
    US Lancaster Va
    Maine Sail,
    Thanks for the reply as well. From yours and Stu's replies I believe that by just moving a few connections I will be able to create one whole house bank and a reserve bank ( lead acid start) by using the existing on/off and 1/2/B switch configuration mentioned in Stu's post. I would then just use the large house battery as the start battery most of the time but would have the reserve battery as a back up. I will wire the alt from the engine to the house bank. The genset does not have an alternator so I don't have that option. I will keep the ACR ( actually a stock VSR) in place and use it to help charge the reserve bank. I still feel like the echo charger would be a good addition as since the engine isn't run for that long the reserve bank will never really get a full change. With the echo at least it would be charged while at the dock.

    (Some explanation) As for the independent breakers on each battery. All of the batteries are connected to busses on both the positive and negative posts and are not directly connected to each other from post to post. Since each of the positive posts run to an individual circuit breaker prior to going to the buss I am able to remove any individual battery from the system with the flip of the breaker. No need to unhook anything as long as the breaker has not failed (welded shut). This was done not only to protect the wiring but also so that any one battery can be removed literally in seconds. I could always add an additional fuse to break the circuit in case of a dead short.

    Since there are two houses busses (one for each bank) all I need to do is connect buss 1 to buss 2 and move the original feed to the #2 position on the house switch from Buss 2 to the starting battery.
    That will then make one whole house bank (AGM) and a reserve bank (lead acid ).

    The 90 charger I bought is an MDP Dolphin. I got it because of the specific charge rates that match exactly what Lifeline wants to see in their batteries. Boost 14.4 and float 13.2 - temp compensated. I actually called Lifeline prior to purchasing and made sure they were ok with the charge parameters of this specific charger. It was the largest charger I could find in the size foot print that would fit in the space I have for it. Most chargers I found in this size only went up to 60 amps. I don't have the space to two chargers. It is interesting because the charger manufacture wants the temp sensor mounted on the positive post ( specifically stated in the manual). Yet ABYC states anything connected to the battery must be fused. Yet you can't fuse a temp sensor.

    Our usage is between 95-105ah a day. The reason I went with 625ah is that 50% would be approximately 300ah. Now I know that the batteries once they left the factory started dropping off from the stated 125ah so realistically I could be around 600ah give or take, but given that we would be using around 100ah a day I figure I could get 2 days worth of use dropping to around 400ah which would require a 30% SOC recovery. Larger bank = less over all usage from the bank = less time to recharge to 100% = Happy AGM's . That was my theory anyway.
     


  18. varigging

    varigging

    Joined Dec 7, 2013
    23 posts, 0 likes
    Hunter 376
    US Lancaster Va

    OK I will forgo the echo charger for now and see how the battery performs. In reality having the 625ah house bank as the main starting battery, I will most likely never need the reserve battery, but will test once a month to make sure that is is good to go just in case. This will enable me to see if the ACR is doing its job.

    Thanks again, this info has been invaluable.
     


  19. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,038 posts, 193 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME
    Please understand that Hunter's version of an ACR/VSR is not normally an ACR/VSR. In older boats it is normally a simple intermittent duty solenoid which parallels the banks when the ignition key is turned on. These are a cost cutting bad idea. Some later Hunters and the Marlow Hunters are now using an actual Blue Sea ACR.

    A true ACR/VSR is activated & deactivated by voltage the same way an Echo Charger is not by the ignition key. The term VSR stands for voltage sensing relay. If your boat actually has a VSR let us know the brand and model. If it is just Hunters ignition activated elcheapo solenoid get rid of it and replace it with a real ACR such as the Blue Sea 7610..

    If you are using a real ACR/VSR it turns on at 13.0V just like the Echo Charger does. An ACR's ON/OFF operation is really no different than an Echo other than it can pass more current and is bi-directional.

    I understand what you did and it still should have been fuses for the AIC. Blue Sea m-Series ON/OFF switches would have cost less and then one fuse could have protected the paralleling bus... What is the amperage rating of each breaker? What is the AIC rating?

    This is good.

    The charger manufacturer is simply wrong on placing the temp sensor on the positive post, would not be the first time... In terms of battery temp it makes no difference which post, but in terms of short circuit protection it needs to be on the negative.

    This is good just wanted to make sure you took actual numbers into the design consideration.

    Your recharge time to 100% SOC is really dictated by the acceptance rate of the battery once you hit constant voltage. It still takes many, many hours.

    For example with a .4C charge rate (40% of Ah capacity or 250A for your bank), from 50% SOC, I can get a Lifeline battery to approx 96% SOC in 2:00. It takes another 3:30 to get to 100%, and that last 4% is still quite critical for overall health....

    At a .2C charge rate 87% SOC can be achieved in about 2 hours but the time to 100% is an additional 3:45 (healthy batteries). Doubling the charge rate from .2C to .4C only shortens the time to 100% by 15 minutes.... That said a .4C charge rate is healthier for a Lifeline AGM than a .2C rate is. Everything is a trade off
     


  20. varigging

    varigging

    Joined Dec 7, 2013
    23 posts, 0 likes
    Hunter 376
    US Lancaster Va
    So you are correct. I have an older hunter VSR ( sorry for not being more clear about that) thus what was leading to my confusion about how the start battery was going to get charged if the ignition was not on. I just went and bought a Blue Seas 7610 and will install that this weekend. I now get what Stu and you were referring to about not needing the echo charger if I use a "real" ACR. This didn't make any sense with my current VSR that only makes the connection when the key is on. So with the new VSR do I need to run the ignition connections? This is labeled as "optional" on the box. If so can I just use the old ignition switch connections that go to the old VSR? I would add the appropriate fusing of corse.

    As for the breakers: Each Blue Seas series 187 breaker is a 125amps and the AIC is rated at 5,000A @12 volts. So I should be fine and they shouldn't weld closed in a dead short correct? There is also a fuse on the line from the charger that is also 125amp as the stated requirement by the battery charger documentation.

    As for the Alternator. Do you have any suggestions 100, 120,140 165 amps etc. Right now obviously my current alt is underpowered, is not Temp regulated and is not programable for the AGM's. But since it is run for such short periods of time ( 1-3 hours at a stent) is it worth the 2k investment to upgrade to help top off the batteries while the engine is running?
     



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