Xantrex C40 diversion mode

HorseflyHorsefly Posts: 310Registered Users ✭✭✭✭
edited March 22 in Wind Power Generation #1
I've got a pretty good handle on solar, but am not familiar much with wind generation.  I'm guessing someone with experience with wind generation and diversion loads can help me.

My sister and brother-in-law (BIL) bought a sailboat a few years ago, already equipped with solar panels, a wind generator, a three-stage charger on the engine alternator, and a 120VAC three-stage battery charger (powered by either shore power or the on-board diesel generator). The "house battery" is a 500AH 12V bank, and there is one 100AH 12V engine battery.

They've taken it out several times for as long as six weeks, but my BIL has never felt like he really had all the info he needed on house power system. I finally got a couple of days to join them in FL to check it all out, and came away with several pages of notes.

The batteries are connected in parallel to all the charging sources:
  • The solar charge controller (BlueSky SolarBoost 2000E MPPT charger)
  • The Xantrex C40 PWM charger in diversion mode, managing the power from a KISS High Output wind generator (or at least that's what I thought it was doing)
  • The 100A alternator (via a Balmar ARS-15 three stage regulator)
  • The 120VAC charger (MasterVolt 12/80), handling 120VAC from either shore power or the diesel generator
Next to the C40 is a board with what looks like rebar segments across it, with the two wires going from the two ends of all the rebars to the C40. In reading the C40 manual and based on what I know of wind generators, this is clearly the diversion load.  It looks as though the rectified output of the wind generator's controller board goes directly to the battery, and the C40 manages the routing of power to the diversion loads. 

This is where I may be confused:  
Since there are all these other charge sources, what is done to ensure the C40 isn't sending power from the alternator, generator, or solar charge controller to the diversion loads? Before I read the C40 manual, I had guessed that the wind generator came to the C40, and that the C40 managed the output voltage to the batteries and/or to the diversion load. However, that clearly isn't the case when the C40 is used in diversion mode. The wind generator is hooked directly to the batteries, and the C40 only looks at the battery voltage to determine if power should be routed through the diversion loads. I don't get that.

Related questions:
  1. Do we have to make sure the charging voltage on the C40 is higher than all the other sources to prevent other sources going to the diversion load? 
  2. Is it safe to conclude that the C40 isn't doing any management of the charging stages when power is coming from the wind generator? Isn't this potentially hard on the batteries?
  3. Is this the standard way that wind and solar are used together? Are there other chargers that perhaps are smarter?
Sorry if these are ignorant questions. I'm a retired EE and I'm sure it will all make sense to me some day....  :|

Steve

P.S. Bill - If this belongs in a different sub-forum, feel free to move it. I wasn't sure.


  
Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 4 x Vmax XTR12-155 12V, 155AH batteries in a 2x2 24V 310AH bank.

Comments

  • EstragonEstragon Posts: 2,848Registered Users ✭✭✭✭✭
    edited March 22 #2
    I don't know much about wind, and less about the c40, but I'll have a go anyway. Being wrong is how to learn.

    I have a pair Morningstar TS pwm controllers for trickle charging, which can do a diversion load if so configured. My understanding of their operation is that the input from the dc source of diversion current is common with the dc diversion load. The controller manages output to the battery according to a set charging algorithm, much as it would from solar or whatever. To the extent current is needed to charge batteries, it pulses to do so. Being common to the diversion load, any excess goes to the dump load.

    It may also help to think of the dump load as the normal load for the wind turbine, preventing it from tearing itself to bits in high winds by loading it down, and the controller diverting available current as/if needed to charge batteries.

    In other words, IMHO, and with the caveat I know nothing about a c40, it seems to me the rectified output of the wind generator should be going to the DC input / dump load terminals of the controller, not directly to the batteries... again stressing I don't really know what I'm talking about, so don't rewire anything unless others agree.

    If others disagree, that's fine, and how I learn stuff.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • HorseflyHorsefly Posts: 310Registered Users ✭✭✭✭
    edited March 22 #3
    Well @Estragon, I hope it doesn't offend you, but you and I think alike.  ;)  How you describe it is exactly how I would THINK it is supposed to work. However, looking at the C40 manual, it seems it isn't that way.

    (Hopefully it shows up)  The wind negative is going to the common ground, and the wind positive is going to the battery (through a disconnect). The only connections on the C40 are for the Battery (+ and -) and the Diversion load (+ and -).   Even if I can say it makes sense (and I don't think I can say that yet), I don't see how to prevent power coming in from Solar or the Generator going to the diversion load. And it certainly doesn't look like the C40 is managing the 3-stage charging of the batteries.
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 4 x Vmax XTR12-155 12V, 155AH batteries in a 2x2 24V 310AH bank.
  • mcgivormcgivor Posts: 2,219Solar Expert ✭✭✭✭✭
    The charger and alternator are self regulating, when a given voltage is achieved they reduce current output to near zero as long as the voltage threshold is met, battery fully charged. Wind generators on the other hand do not regulate so they would continue to force current into the battery thereby raising the voltage to undesirable levels. The division controller will divert the wind generator's output to the diversion load, as long as the battery voltage remains high enoughor fully charged.These voltage thresholds are what would be programmed into the diversion controller. 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 

  • mike95490mike95490 Posts: 7,916Solar Expert ✭✭✭✭
    There should also be a "brake" switch or a "shutdown", so the turbine can not spin needlessly in a storm
    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 ,

  • BB.BB. Posts: 27,906Super Moderators, Administrators admin
    As I understand a "basic" mixed charging system... You would normally set your Absorb (peak charging) to (for example) 14.7 volts. And set the dump load at ~14.9 volts. (this is for flooded cell batteries... For AGM/Sealed batteries, probably closer to 14.2 absorb and 14.4 volts dump).

    For most wind power systems, they only charge a lot a few times (battery full, windy/stormy weather). If you set the dump > the maximum charging voltages for the rest of the charging sources, the batteries are usually OK.

    If, however, you have a good wind turbine and lots of wind, you may need to back the dump voltage down to prevent over charging.

    And, of course, if you equalize the battery bank, you will have to set everything for manual equalization (you decide when to equalize and what controller(s) will do the equalization).

    If you have good amount of solar panels, probably tie up the wind turbine when the boat is not occupied and loads are turned off--Let the solar/shore power keep the bank charged (I am not a fan of wind turbines--especially if unattended).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • HorseflyHorsefly Posts: 310Registered Users ✭✭✭✭
    Thanks Bill (and @mcgivor and @mike95490).  I pretty much already understood what both @mcgivor and @mike95490 are saying. I think my problem was I couldn't see why the wind generator's C40 would for sure not be shunting power from another source to the diversion load. However, I think @BB. has given me the clue. I think what you are saying is that as long as I have the bulk and float voltages of the C40 set higher than the bulk and float voltages of all the other sources, then the C40 would only go into diversion mode if the voltage from the wind generator exceeds those settings.

    The wind generator on the boat in question isn't working right now. We think there is a broken wire in the mast. So my only worry was what will the C40 be doing. Since it only watches the voltage at the battery, I was worried it my be diverting generator, alternator, or charger power. Since I'm not there and they are preparing to sail to the Bahamas for at least a month, I think I'm going to tell them to disconnect or otherwise disable the C40.
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 4 x Vmax XTR12-155 12V, 155AH batteries in a 2x2 24V 310AH bank.
  • BB.BB. Posts: 27,906Super Moderators, Administrators admin
    The C40 would be set to Absorb only in diverson/dump mode (I believe that is is how it is done). That way, no confusion about one charging source trying to Absorb while the C40 was dumping thinking that the battery bank should be in float.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • HorseflyHorsefly Posts: 310Registered Users ✭✭✭✭
    BB. said:
    The C40 would be set to Absorb only in diverson/dump mode (I believe that is is how it is done). That way, no confusion about one charging source trying to Absorb while the C40 was dumping thinking that the battery bank should be in float.

    -Bill
    Ohhhhh. So you're saying the C40 in this mode doesn't do float at all? I think that would make me worry WAAAY less. My concern obviously was that the C40 would be trying to float and some other source would be trying to do absorption, so the C40 would dump all the power from the other sources. However, if the C40 doesn't care about float, it would only do diversion to the dump load when the battery voltage was higher, at bulk / absorption.  

    I'll look for more info on that aspect. It hadn't occurred to me. Thanks Bill!
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 4 x Vmax XTR12-155 12V, 155AH batteries in a 2x2 24V 310AH bank.
  • Dave AngeliniDave Angelini Posts: 4,021Solar Expert ✭✭✭✭
    One of the best ways to get new batteries is a wind generator on a sailboat.

     I made good income from wind generators. I think when they actually start using the boat they will find that they have to anchor in windy places which is the last thing you want after being in the wind making a passage.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • HorseflyHorsefly Posts: 310Registered Users ✭✭✭✭
    One of the best ways to get new batteries is a wind generator on a sailboat.

     I made good income from wind generators. I think when they actually start using the boat they will find that they have to anchor in windy places which is the last thing you want after being in the wind making a passage.
    Dave - That makes sense. They've already crossed the from FL over to the Bahamas once last year, and leave to do it again next week. They don't seem concerned at all about not having the wind generator, and maybe it is because of what you are describing. I somehow thought that it would generate enough to be worth it while they were sailing. Apparently it takes 20 hrs of sailing to get across, and I figured having the wind generator all that time would be worthwhile. If they actually have to be at anchor, I see why it isn't so useful.

    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 4 x Vmax XTR12-155 12V, 155AH batteries in a 2x2 24V 310AH bank.
  • BB.BB. Posts: 27,906Super Moderators, Administrators admin
    You have to check the manual. Either program float off, or set float voltage = absorb voltage.

    I don't know if the C40 can do this, but that is where I would start.

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Dave AngeliniDave Angelini Posts: 4,021Solar Expert ✭✭✭✭
    Yes it will by adjusting set-points and jumpers. I still have one that says Trace on it  :) There is no "programming" of  a C40 in modern terms!
    Thanks for the rain Bill. Up to 35" for the season!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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