Changing Charge Controllers

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I have an off grid system that I need some advice on. I have 8, 120 watt panels wired for 24v and feeding into a Xantrex C40 charge controller powering 12 L16 batteries going into a Xantrex SW 4024 inverter. The inverter and charge controller was set up on a Xantrex factory power panel with disconnect etc...

My question is this. I am thinking about going to an MPPT Charge Controler and was wondering what would be a better choice for me, an Outback Flexmax 80 or the Xantrex XW 60?

We are going to be living at this house in the near future and need to maximize all the power that our panels produce. We also have 6 more 120w panels that I plan on adding to our present system. I will be doing the charge controller changeover myself and am concered at how difficult this will be and also about compatability with my system Any advice would be welcome. Thanks

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  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Changing Charge Controllers

    If your living with the system the XW for sure over the Outback. Outbacks are very noisy, I literally have to move my office to another room when testing those controllers its that loud.

    The new MorningStar Mppt unit is also convection cooled, higher efficiency and and more features than either the FM or XW units, worth a look at
  • System2
    System2 Posts: 6,290 admin
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    Re: Changing Charge Controllers

    Solar Guppy, How easy is the change over from the C40 to a MPPT?
  • blackswan555
    blackswan555 Solar Expert Posts: 246 ✭✭
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    Re: Changing Charge Controllers

    From installing Outback,
    "How easy is the change over from the C40 to a MPPT?"

    Reasonably easy, PV +/- in from panels, +/- out to bat, remote temp sensor plugs in, Power up, it finds bat voltage, a few presses to dial in your V & time settings,
    The one thing you have to check is your panel wiring, you want to be aiming for a VMP of approx double your bat voltage, Probably the hardest bit if you have to re-configure,

    Have a good one
    Tim
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Changing Charge Controllers
    blindref wrote: »
    Solar Guppy, How easy is the change over from the C40 to a MPPT?

    Very easy if you have some room around the controller as the XW chassis is bigger than the C40, The MorningStart Mppt is very close to the C40 outline.

    Keep in mind the XW-Mppt is a 4 wire controller, the C40 is a three wire controller ( common ground )

    So for the XW-Mppt the PV +/- wire to the controller and a separate pair of +/- wire to the battery ( likely breaker )



    For the MorningStar Mppt, its identical to the C40, the PV- and Battery- are common so wires change 1 to 1. One neat feature about the MorningStar controller is it can run to 100% duty cycle so there is no Vin/Vout minimum, the XW-Mppt is about 97% maximum or a Vin/Vout minimum of 1V. This becomes important when your running the nominal panel voltage close to the battery voltage as you do with the C40 pwm controller
  • blackswan555
    blackswan555 Solar Expert Posts: 246 ✭✭
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    Re: Changing Charge Controllers

    AFAIR the FM neutral is also common, so if you bus bar, you only need 1,

    Tim
  • audredger
    audredger Solar Expert Posts: 272 ✭✭
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    Re: Changing Charge Controllers

    I'm happy with my outbacks. Solarguppy is correct they can be noisy however, they work well. Note: my battery shack is 150' away from the house so noise is not an issue.
  • boB
    boB Solar Expert Posts: 1,030 ✭✭✭✭
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    Re: Changing Charge Controllers
    audredger wrote: »
    I'm happy with my outbacks. Solarguppy is correct they can be noisy however, they work well. Note: my battery shack is 150' away from the house so noise is not an issue.

    There is one good thing to say about fans, (that is if they don't fail), and that is that they can keep the power electronics from getting too hot for too long and failing prematurely. Heat is the enemy of power electronics and I know that the XW60 (and others) can get very hot.

    At least the FM80's fan can be replaced fairly easily if it does happen to fail.
    Noise ? I sleep with a fan on so it doesn't bother me. I don't sleep with a charge controller though which is probably more than you wanted to know. :D

    boB
  • BB.
    BB. Super Moderators, Administrators Posts: 33,479 admin
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    Re: Changing Charge Controllers
    boB wrote: »
    I don't sleep with a charge controller though...

    I am crushed!!! ;)

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • halfcrazy
    halfcrazy Solar Expert Posts: 720 ✭✭✭
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    Re: Changing Charge Controllers

    I think he probably does sleep with the Classic maybe not but it is with him most of the day I am sure.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: Changing Charge Controllers

    My MX60 isn't that noisy; the fan only comes on when needed, and that would be at peak charge current during the day. Never yet had it come on at night, even when it was trying to charge from the full moon! :p

    General note about heat & CC's is that the closer you run to the maximum current level, the more problem heat becomes. Mine operates at about 50% max, so it doesn't have too much heat to deal with.