Xantrex settings changed, now charging batteries all night from grid

I'm trying to deal with my small battery bank constant overvoltage fault and accidentally changed a setting somewhere. I thought I was careful to write down all my settings and thought I verified I didn't change anything. But when I got home at 11pm I noticed the trimetric charging light was on. Went to the control station and it's definitely grid charging. Any suggestions on which settings I might have changed and what they should be would be welcome

3 strings of 3 235s, xantrex 4548, mppt60, 139Ah at 48v lead acid, firm ware updated 09/2012

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Xantrex settings changed, now charging batteries all night from grid

    Welcome to the forum.

    We might as well get this part over with before the "Xantrex guys" show up and start telling you about the nightmare that is XW programming. :p
    You realize that is an extremely small battery bank for that inverter? It is just possible it needs charging from the grid because it is having too much power drawn from it.
    Three strings of three 235 Watt panels? That would be 2115 Watts. That is an extremely small battery bank for that much solar too. That array could support 340 Amp hours.
    You have not got this set to try to feed the grid, have you? Because that is an extremely small battery bank for grid-tie function.

    Er, do you see a trend here? :D

    I try to avoid Xantrex products myself (once bitten, twice shy) but I'm sure there's a way to limit charge time or AC IN function. We'll let the Xantrex guys have their say. :D
  • TheNestTheNest Registered Users Posts: 3
    Re: Xantrex settings changed, now charging batteries all night from grid

    yes, we're trying to feed the grid, in theory the batteries were sized to run the new DC powered panel: fridge, freezer, three small lights. I obviously don't understand what I was sold. Neither the designer, the installer, their service guys nor Xantrex are being very helpful. And we knew about Xantrex before we got this system; we lived Xantrex for 5 years on the "other" system which was much smaller and I knew how it worked even if it didn't work the way the manual said it did. I figure I've got four options 1) get the settings straight 2) spend mucho bucks for bigger battery bank 3) replace the xantrex with an outback and take out the batteries 4) pray xantrex gets a new firmware out next week that supports the 100 amp hour battery bank that the manual claims they support

    The system was supposed to be designed as the first phase of getting off grid, with a small battery bank just to keep a few things running when the power goes out from the grid. I wanted to wait two or three years to build up some cash before investing in a brand spanking new expensive battery bank. And yes, I paid good money for someone to design this system for me and no, I did not do my homework on their recommendations, except to call xantrex and see if a real person answered the phone, which they never used to do when they were xantrex/link/heart.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Xantrex settings changed, now charging batteries all night from grid

    Xantrex not helpful? :roll: Oh how often have we heard that!
    They probably didn't even mention that for an XW4548 to work properly with the grid you need at least 450 Amp hours of battery bank. That is the "100 Amp hour battery bank" the manual is talking about: 100 Amp hours per kilowatt of inverter capacity. This is notoriously unclear.
    And along with the larger battery bank comes the need for more panels to recharge it. Like about 2800 Watts worth.

    First thing I'd do is stop it from trying to sell to the grid. I don't know who installed this for you, but they sure did it wrong. Supposedly a grid-tie system should be loaded with planning and permits, but even if so that doesn't mean they get the panel-battery-inverter ratios right.

    Firmware upgrades on Xantrex equipment is another nightmare, as it requires some mysterious device called a "dongle" which they don't supply for free. It probably wouldn't solve the problem here anyway.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Xantrex settings changed, now charging batteries all night from grid

    i'm wondering if that is an ac overvoltage fault. do you have a meter that can measure what the grid voltage is without you selling power at the time, or get someone to measure it for you? if the grid is too high in voltage the inverter can't properly sell to the grid and what's worse the high voltage being fed to your house will damage things while causing an abnormally higher power draw for many items there leading to you being billed more too.
  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    Re: Xantrex settings changed, now charging batteries all night from grid

    It sounds like you have it set to float or three stage charging instead of 2 stage with no float. It is under the advance menu and charging, this is off the top of my head though.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • TheNestTheNest Registered Users Posts: 3
    Re: Xantrex settings changed, now charging batteries all night from grid

    I'll look into the grid voltage in tomorrow, as well as turning off SELL. I found my immediate problem which was that my batteries kept charging from the grid. When I changed grid support voltage from 54 to 50, recharge voltage changed automatically from 54 to 50 as well. I caught this and changed it back, so I thought. The recharge value was automatically changed to 50 in two places and I only reset one. I found this tonight as I went through every menu and submenu and rechecked every value.

    No, I hear the inverter running again, I just bought myself 20 minutes of not charging. Crap. My husband will call our designer, installer, SunDance of Weaverville, NC, tomorrow, and talk about the not quite complete design sizing and what we do from here.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Xantrex settings changed, now charging batteries all night from grid
    TheNest wrote: »
    The system was supposed to be designed as the first phase of getting off grid...
    Why do you want to do that? Are you comfortable with the idea of spending 10X or more in perpetuity for your electric power?
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