Xantrex C60 as a 12V charger from 24V battery bank

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  • IyaIya Solar Expert Posts: 32
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    Hello All,

    Gee, the forum is really great !! Everyone so helpful, many thanks guys.


    dwt,

    Typical automotive or even marine alternator charging section is not too smart but it does the job decently well. Look for Balmar brand with its stand alone smart charging regulator which you can tune to the battery needs. Big amps alternator need twin belts and some engines doesn't have the pulley to handle that.
    If an automotive engine be it diesel or gas is use as a DC generator, it will be a waste of power, unless one can couple it on the flywheel end and really juice out 60% the engine power....wow !!




    Greener,

    Thanks for the DC to DC converter link.
    Depending on the vessel class and law of the country, a 12V battery bank can be a MUST have, a DC to DC converter or 12V power supply from a 230v source being a primary supply may not be acceptable.

    This vessel I am doing will not be classed, its a traditional wooden boat but it will do partial charter and experience shows that battery is more reliable than any electronics power supply ( given the battery is maintained properly ).
    The most common method on bigger vessel is to have a 12V battery bank with a battery charger powered from the generator. So if battery charger failed, few hours talk time still available and that can mean do or die in emergency situation.
    Investing in a 12V dedicated radio battery bank with good charger, better with 2 good chargers is money well spent at sea. Communication is vital because I am talking of a vessel being hundred of miles from nearest land. Even marine sattelite phone runs on 12Vor 24V.

    I say that in a 24V vessel, a 24V is the most reliable because 24V is the primary lighting system and engine starting system ( separate bank ). Nothing to do with higher voltage than a 12V. So this is the system that all on board will notice, if ever anything goes wrong. So this is the battery bank that everyone loves to maintain since no one likes pumps not running, lights being dimmed and whatever creature comfort they can't do without 24V. This is also the only system available when everything else "internal combustion engine based" failed.

    A vessel may have few engines and few generators, however there is only 1 fuel supply. Bad fuel can stall all generators and main engines. Unfortunately for diesel fuel, when the weather get rough, all the dirt in the tank gets scrubbed off from tank walls and start clogging filters. Something bad we do not need in heavy weather but that always happen. This vessel will have 5,000 gallons fuel and any experienced sailor will tell you that in some countries, up to 5% of that fuel could be water, slime and whatever dirt which will clogged even the biggest fuel filter in a heart beat.

    So, not having a dedicated 12V radio battery bank ( on a 24V system ) to be able to communicate for at least 1-2 hours after a charging system failure is a gamble no experienced sailor will ever take.

    Why I insist to have a DC to DC converter with charging capabilites been explained.




    SG,

    What Morningstar said about "never" use MPPT as DC to DC battery charge controller if source is a battery bank instead of a PV scares me but your approval on the mppt as long there is a battery on the load side sure smooth things out.
    Assuming the vessel crew remove the 12V battery for some reason and run the radio with the MPPT connected, what will happen ?Thanks.



    Guys,

    I did a Google search again and I refine to" DC SOURCE CHARGER" and I got this product from Analytic System, a 12V 25 Amps charger from 24 to 36 V DC input.
    http://www.analyticsystems.com/Original%20Site/aboutus.htm

    Seems like a good product the Analytic but rather expensive at US$ 485
    http://www.semarine.com/store/product.php?productid=85&cat=140&page=1

    If it is 100% safe to use the Morningstar MPPT ( +- US$278 ) as a DC to DC charger, assuming it won't fry when the radio battery got removed, 15 amps is not too bad considering the radio transmission time will be very low.




    Niel / Mike / Cari,

    I imported Lifeline AGM sometime in 2003. Group 27, 12 units for a friend's yacht.
    They are good batteries and its so true that elevated temperature DO kill batteries.

    The Lifeline died on me in about 3 years when used as engine starting batteries in a hot engine room of 45*C ambient operating temperature and all the while it is nearly zero discharged operation mode because there is no load taken from it. It is a strictly engine starting batteries application even though the design is more for deepcycle.

    The same battery used as domestic battery bank and kept in cooler place away from engines survived 3+ years before the yacht was sold, so I did not know the actual life after that. The yacht was under constant 24/7 shorepower feeding the Newmar Three Phase charger. When engines or generator are running all banks get charged from big alternators and that Newmar. So it wasn't a tough operating environment as far as deep cyling is corncerned.

    Maybe this time I will try Traction batteries from local Yuasa dealer for this wooden vessel. Its expensive to ship batteries from USA and no one sells marine AGM here, hence I need to import them in 2003.

    I do like the idea of no maintenance on the AGM compared to filling up lead acid batteries but for replacement convience I may need to choose what is locallyy available and buy more often....:cry:

    Automotive batteries surely doesn't belong on yachts for deep cycle application, that is so true too.


    Photo,
    Agree on standy-by, the radios will consume so little.
    The SSB at transmission is quite power greedy though....:D



    Guys,
    For your curiosity sake, this is what I have in mind for the 12V radio battery bank.

    Basic System
    - 2 x 100 amps battery as 12V
    - Battery charger #1 maybe from Vetus or Xantrex.
    - Battery charger #2 maybe that DC to DC charger 25 amps from Analytic


    12v Source Selection :

    Main 1 - Battery bank with two chargers running, if there is no conflict between the two chargers. If there is conflict, I will use DC to DC charger ( #2 ) as primary charger.

    Main 2 -
    Battery bank with Charger #1 ( assuming charger #1 & #2 has conflict )

    Source selection switch will be a 4 poles type at least 32 amps.
    4 poles if there in conflict between the two chargers, 2 poles if there is no conflict.
    With 4 poles I can cut-off battery chargers 12V outputs at the same time its 230V input or its 24V input for DC to DC charger, at time of selection.

    Emergency 1 -
    12V center tap from 24V domestic battery bank

    Emergency 2 -
    12V center tap from 24V engine starting batteries bank


    For emergency I can actually do secondary sources switching with another switch if I decided to use all available options.


    Emergency -And choose sub-selection with a secondary selector switch 4 way, 2 poles.

    Emergency Sub-Selector Switch
    #1 - 12V center tap from 24V domestic battery bank
    #2 - 12V center tap from 24V engine starting batteries
    #3 - 12V from generator #1, 12V starting battery
    #4 - 12V from generator #2, 12V starting battery

    All 4 emergency source will have 30 amps blocking diode to prevent radio battery from participating in engine starting or being discharged, since this will be a parralel connection.

    The 4 sources of emergency 12V supply is cheap to do. Some length of wires and 4 MCBs close to each battery banks. Do you guys think its an overkill ?
    When the vessel is fully constructed, I will have a hard time doing the wiring. Now its time to insert into the main wiring plan, if it can be justified.

    There will be 1 SSB radio on board. I plan to have 2 fix mounted VHF.


    Thanks guys....
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    iya,
    2 things i'll address that stand out are,
    1> a switch can be turned easily in a non-emergency situation too so some safeguarding of such a maneuver should be utilized. be sure the switch is a good quality hd dc switch and not something as unreliable as a radio shack switch if you have those there to know what i'm talking about. also , i have add make sure your wires are sufficient for the loads.
    2> 3 radios on simultaneously even only receiving will draw much more than you think and i'm glad to hear you will go the extra ah capacity. i based my estimate for the soc with only a 1.5a draw. the ssb radio alone may be in the neighborhood of that 1.5a in receive and turning the volume higher increases that draw slightly too.
    do note that your 25w vhf radios have a carrier that will consume a great deal of power when transmitting and can be almost as much of a dc power draw as a 100w ssb transmission at times. do not be confused by the radio power watts as this refers to the rf output and not what it takes to produce that power from the dc source as it is much higher from there no matter what transmission method is used. ssb transmissions are a very efficient transmission method compared to fm or am though.
  • IyaIya Solar Expert Posts: 32
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    Hello Niel,

    Thank you for the tips. OK, I will use the 3% voltage drop rating. Switches I will use industrial ones from Telemechanique or similiar and at least 1 size up. Marine ones from BlueSea or similiar good brands are hard to find here, except the 600 amps battery switch. This 86 footer slow wooden vessel is dry, I mean dry as it is not like small center console go fast boats where all swiches are best IPX7 rated if possible due to wet ride.

    I will need to educate the captain and the crew on the 12V DC source selection switch for the radios, that I must do. What I usually do is I will get them involved during the wiring process so they not only understand the wiring run but the philosophy of the design. They can even troubleshoot on their own later.
    My own small 34 footer boat has complex DC wiring and my captain who was also my asisstance during the wiring have done well even though he doesn't actually understand DC or AC system all that well.

    Yep, noted on actual consumption of radios, typical 1.3 times of TX watt is how I calculate as minimum actual consumption on battery. Marine VHF for boats at high power is 25 TX watts maximum by law. Will measure the amps on transmit, roger that, thanks.

    Any other input will be appreciated....;)

    IYA
  • GreenerPowerGreenerPower Solar Expert Posts: 264 ✭✭✭✭✭✭
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    Wow! now I see the scope of your design. A few comments:
    * A typical MPPT controller, depending on its internal algorithm, would "sweep" or somehow "search" for the maximum power point on the PV curve. With 24V battery source in place of the traditional PV, it'll eventually "park" at its maximum current output as the MPP . During these "sweep/search" periods, the charging current is either ramped up from 0 or slightly changed momentarily from its optimal point. This is probably why MorningStar doesn't recommend to use as charger with 24V battery source (not harmful but not optimized as charger). SG probably knows more about this and whether this could be minimized or disabled.
    * Check with MorningStar if it could be used in your marine environment (it is stated 100% non-condensing humudity, marine grade terminals, not sure about the internal components). Analytic and MasterVolt chargers are marine-grade chargers (and hence pricy). MasterVolt has a 24-12V unit that is both charger and DC-DC converter. The MeanWell DC-DC converter in the link I provided is certainly not for marine environment.
    GP
  • mike95490mike95490 Solar Expert Posts: 8,967 ✭✭✭✭✭
    Re: Xantrex C60 as a 12V charger from 24V battery bank
    What Morningstar said about "never" use MPPT as DC to DC battery charge controller if source is a battery bank instead of a PV scares me but your approval on the mppt as long there is a battery on the load side sure smooth things out.

    Assuming the vessel crew remove the 12V battery for some reason and run the radio with the MPPT connected, what will happen ?Thanks.

    What will happen? Without a 12V battery at the output of the MPPT, it will likely shut down, or smoke your radios. Or both. It won't be good.

    What WOULD happen, is I would find the crewman who took the 12V battery, replace it with an equal amount of weight, and eject him.

    What would you do with any crewman who just "took" a critical piece of gear?

    "Sure man, I sold that bronze prop off of the aux engine shaft, we didn't use it last trip."
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • IyaIya Solar Expert Posts: 32
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    Green,

    Wow, that is even better info. Yes, that makes sense since MPPT make sweeps to determine best condition...thank you Sir.

    I know Mastervolt, they are expensive too and European brand, the Analytic I just learned of yesterday. I will look into Mastervolt products, haven't surf them for 2 years now.

    Marine grade are sometimes too much sales talk, but depending on brand.
    The good switches are usually copper contact points and tinned coated, so are the wires. Cheaper switches are brass contact point.

    Some circuit boards are clear coated so the soldering do not get corodded but they are a pain to repair since we must burn off that coating first...:p

    Depending on what kind of boats, size and placement of equipment, many industrial gear can be used on "dry" boats.

    Death due to corrosion is something one can't avoid in the end in a boat but service life can be extended with great ( & lots of sweat ) care.

    Bad contact is the worse enemy on boats electrical system. Often terminals, switches and even MCBs got oxidize and each can present some 3 ohms resistance. Some MCB I can salvage using CRC contact cleaner, some simply stay at 3-5 ohms and have to be disposed. Its a pain to troubleshoot old marine electrical connections since I can't read real voltage drop unlesss I load the circuit up and undo all connections to read each wire and connection resistance. At low such low voltage slight resistance is a big deal.

    Understanding 0.3 volts shortage due to bad contact can mean battery bank can never be charged properly, it not a suprise many boats charging system goes bad fast.

    You keep a new copper wire ( not tinned coated ) for 1 month on a boat as back up, at least the first few meters of each end will oxidize and can,t be soldered.
    I crimp and soldered all small diameter connections up to approx 4mm diameter cable, its so time consuming.

    I once had a 12v 10 watts halogen bulb, hot sealed in a clear plastic factory packaging. Kept for a year on board and when I use it, it will not light up. Dang, it was simply oxidation I can't clearly see due to the small size of the bulb pins. Maybe small pin hole leak in packaging that I can't spot. Sand the pins down using 400 grit, and only then it lights up.

    All these slowly oxidizing connections sometimes fooled me, I thought I had a slow short circuit due to overload because MCB will pop only after 15 minutes or more of equipment run. Purely it was a bad contact, low voltage, increased amps and MCB will pop eventually.

    Sometime I even come across low quality wire that has insulation failure due to placement in wet zone and it is for a 230V system. Usually wire insulation less than 1 mega ohm will pop the MCB only after equipment been running some ten or twenty minutes. Some really shitty wire will read 60 volts on its insulation and will turn on a test light....:p

    This is why I really like this forum because low voltage DC system is more complex and less forgiving than usual 230V AC supply....to get it to work 100% flawless.
    I learn a lot of DC matters here...you guys here are great !!! Two thumbs up.

    Again, I have to repeat...the solar charger capabilities...I really like it.
    It can be fine tuned in many ways unlike most marine DC chargers.



    Mike,
    I like that.....;) , that's a good one and so true. Nibral props are high on a thief list.
    OK, great info. There goes the MPPT as charger candidate then. I just email Analytic and ask them the same battery-less scenario for the DC source charger. I hope it can behave like a typical good quality marine battery charger which can purely be used as power supply without batteries.

    In a case where a boat crew will remove a radio battery, is most likely when the generator have a bad battery, so he borrowed it for a while.... ha ha ha. Unknowingly the captain then use the Radio...my my...that can happen.


    Thanks guys
    IYA
  • Solar GuppySolar Guppy Solar Expert Posts: 1,963 ✭✭✭
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    The MorningStar Sunsaver Mppt will work 100% fine having a 24V battery as the source, No issues what so ever. The units boards are epoxy covered on the bottom and conformal coated on the top, so corrosion should be not an issue with the internals of the charger. The Sunsaver Mppt is a sweep design, once every two minutes but is unique about this brand is the sweep is done in 250ms ( one quarter of a second ). Unless you have a power analyzer on it you would never know this is happening, its also the reason the Mppt never gets stuck as its performing a full sweep each time.

    Most Mppt controllers are powered from the battery side, no battery, no power conversion.
  • BB.BB. Super Moderators, Administrators Posts: 30,946 admin
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    Make sure, that if you put a MorningStar PV input on a battery instead--that you use an appropriate sized fuse or breaker for protection.

    Also, you might need to look at using a breaker/switch such that you can shut down the MS Converter when you don't want the drain from your 24 volt bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • IyaIya Solar Expert Posts: 32
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    SG,
    Can I bother you for one last confirmation please.
    If ever the 12V radio battery bank get removed or disconnected, will the MPPT get fried by being a pure DC powers supply for the radio ?
    Thanks


    BB,
    OK noted with thanks.

    IYA
  • Solar GuppySolar Guppy Solar Expert Posts: 1,963 ✭✭✭
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    No issues with SunsaverMppt and battery removal , that being the unit would not be damaged, you just won't have any 12V anything as the controller requires a 12V source to power it, when battery is removed, no power and controller is inactive.
  • IyaIya Solar Expert Posts: 32
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    Thank you Chief....
  • BB.BB. Super Moderators, Administrators Posts: 30,946 admin
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    I would recommend that breaker/fuses/switches be pulled to the radio gear before popping the battery out (with the controller attached and powered). You could get a voltage spike and take out your expensive gear.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • IyaIya Solar Expert Posts: 32
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    BB,

    I plan to install a two pole MCB ( so I can cut out - and + ) at the 24V battery bank side, as close as possible to the 24V battery bank, when feeding the MPPT or even when using a DC Sourced Charger.

    At the 12V Radio Battery Source Selector Switch, I will use a 4 pole. So I can again cut out the - & + for the 24V input of the MPPT ( or DC Sourced Charger ) and also the - & + of 12V out put of the MPPT ( or DC Sourced Charger). I think this is as safe as I can get....yes ?

    Thanks
  • BB.BB. Super Moderators, Administrators Posts: 30,946 admin
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    I am not sure that you need to break both the + and - legs... Won't the system have common negative ground for both banks?

    And for Solar Guppy--

    Just to confirm that the MS MPPT Charge Controller can work with a common negative ground battery bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • IyaIya Solar Expert Posts: 32
    Re: Xantrex C60 as a 12V charger from 24V battery bank

    BB,

    I want to be able to float the 12V radio battery bank ground/(-)
    It won't be connected to common ground, unless that 2 pole MCB is turned on.
    The SSB antena will be the second highest structure on the boat, at 23 feet long and a mere 6 feet shorter than the lighting rod I want to install.

    I know an MCB gap is too small to prevent a lightning strike from jumping but I feel comfortable if I can remove any direct be it - or + connection towards the 24V domestic battery bank during a lightning storm .....if for some unlucky reason the SSB antena get hit by lightning. The 24V domestic bank will be connected to the 24V starter battery bank thu an alternator charge splitter, if the domestic bank ever get stray strike via 12V Radio Bat Bank, I am afraid engine starting battery will get fried also.

    I don't know the fuel solenoid arrangement of the vessel's engine but if it is N/C type, without 24V the engine will be killed thru fuel starvation. This is a non electronic engine so the only DC power it needs is for its alternator regulator and that fuel shut off solenoid which acts as engine kill switch too. If the vessel loose the engine in heavy sea even for 5 minutes, things can go bad fast. I will modify the fuel shut solenoid as N/O if it is ever an N/C, it is safer.

    I will have separate SSB radio ground as counterpoise ( i think that's what it is called ) and lightning ground plate on the hull but at 1 over million volts, God knows what will happen.

    I may not ground main engine chassis, I don't know yet. Still thinking and thinking.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,963 ✭✭✭
    Re: Xantrex C60 as a 12V charger from 24V battery bank
    BB. wrote: »
    Just to confirm that the MS MPPT Charge Controller can work with a common negative ground battery bank.

    -Bill

    Yes, common ground is fine all MorningStar Controllers
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Xantrex C60 as a 12V charger from 24V battery bank
    Yes, common ground is fine all MorningStar Controllers

    Is that common ground the same (-) terminal on that for input and output?

    If the 24V system has the chassis connected to the inter-battery connection and the (-) input on the Morningstar is connected to (-) 24V and the (-) output for 12V is also connected to chassis at some point then you have a dead short across the (-) 12V to chassis.

    Or to put it another way (in hopes I'll find one that explains what I'm trying to say):

    Existing system = (-)12V * CHASSIS * (+)12V [24V total]

    Radio system = (-)12V connected to CHASSIS

    Morningstar MPPT = (-) IN connected to (-)12V on existing system, (-) OUT connected to (-)12V on radio system, and (-) IN connected to (-) OUT. In this case the controller creates a short from (-)12 on the existing system to CHASSIS via the (-)12V on the radio system.

    I'm not saying this is (or will be) the case, just a potential problem. The solution being to isolate (-) of the radio system so it is not tied to CHASSIS (if that is connected as above).
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