SunSaver MPPT Controller and Sun Xtender AGM batteries

_OS_
_OS_ Solar Expert Posts: 207 ✭✭✭
Hi!

I received my new SunSaver MPPT controller today and wonder if anyone has been using it with the Concorde Sun Xtender batteries. The SunSaver have a setting for AGM batteries but I am not sure if this setting is optimal for the Sun Xtender batteries (PV 2580L).

Thanks!

Ole

Comments

  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    See section 4.7 on the user manual (page 32) for information on customizing the SunSaver MPPT controller's settings.

    HTH,
    Jim / crewzer
  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    Yes I have read the manual and I wonder if I can use the default settings. I do not have the Meterbus to Serial Adapter so I can't change the settings either. But I can order it if I need it.

    Ole
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    Adapter is Free, just call and ask for one from MorningStar
  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries
    Adapter is Free, just call and ask for one from MorningStar

    Hi,

    I mailed them yesterday after reading your message and received an e-mail now that they are sending me the interface for free! I live in Europe and they cover the S&H charges as well. I can't believe it!

    Have a nice weekend!

    Ole
  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    Cool news! I hope you'll report back on the performance of your system.

    Regards,
    Jim / crewzer
  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    I managed to log onto the SS-MPPT this weekend with my PC. I used the MSView program and changed the Temperature Compensation Coefficient from -31mV/C to -23mV/C which closer matches my Sun Xtender batteries (-3.75mV/cell).

    When I programmed the SS-MPPT with the new settings the status LED went solid red and the battery status LED's were sequencing. Anybody else seen this? I fired up the SCView program and the status said EEPROM Error. The problem disappeared after I removed the power from the unit for a few seconds and then reconnected the power again.

    Ole
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    On all MS products when EEprom values are changed you have to restart the unit, so what you saw was normal operation.
  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries
    On all MS products when EEprom values are changed you have to restart the unit, so what you saw was normal operation.

    Thanks for the information. Do you know if MS updates the firmware in their controllers from time to time?

    Ole
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    Yes. MS updates firmware when the need arises ... you can check the http://www.morningstarcorp.com/en/support/product.cfm?Name=SunSaver%20MPPT website for flash updates which as of now there are none
  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    One thing I forgot to mention is that the Morningstar documentation for the serial dongle said to use a straight through RJ-11 cable. This did not work for me; I had to use a crossover cable.

    I my world a straight through cable is wired like this (and that did not work for me):

    RJ11-14FT-STRAIGHT.jpg
  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    One thing I noticed last weekend when I checked my system was that the Trimetric showed a max voltage of 15.1V for the last three months. It has been very cold here for many days prior to my visit; below -10C. I checked the SunXtender datasheet and it calls for a charge voltage of more than 15.5V at these temperatures. I mailed Morningstar about this and here is the response:
    The SS MPPT has an uncompensated max regulation voltage of 15V for a 12V system. This means that no matter how cold it gets, the controller will never deliver more than 15V to the battery bank.

    My question now is: will this be a problem for my batteries? I have e-mailed Concorde as well but have not got any response yet.

    Thanks,
    OS
  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    From the Sun Xtender Technical Manual (PDF Download):
    VPC(Absorption) = 0.00004T^2 -0.006T + 2.525 (where T = °C)
    VPC (Float) = 0.00004T^2 -0.006T + 2.335 (where T = °C), but not less than 2.20 volts per cell.

    T= -10C (Tsquared--don't know how the +/- sign behaves above/below below zero)--but the second term *0.006T is much larger than the T^2 term. (0.004<0.06)

    Vpc (absorb) = 14.40v at 77F and 12 volt battery
    Vpc (absorb) = 2.589v per cell @-10C or x6 = 15.534 volts max.
    Vpc (float) = 2.339v per cell @-10C or x6 = 14.394 volts max.

    I am guessing your battery may charge slower (flips to Absorb cycle from fast/Bulk charging sooner) at 15.1 volts vs 15.534 volts... However, the float voltage is still with range. So, no damage at least.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    i don't think you will be in trouble here as i believe that you stated in the coldest times the batteries are not in use and that the pvs are just being used in maintaining the batteries at this point in time. at the beginning of the hibernation period for your cabin, if the batteries started off with a full charge they will discharge slowly at a rate of about 1% per month at 25 degrees c without any charge applied. it may be a good idea in getting concorde's opinion specific to your situation, but i think it'll be ok especially being there is something being applied in maintenance even though just shy of the recommended voltage of 15.5v(not confirmed in my reading) you say it needs. i figure it to be closer to 15.1875v at -10c by using the 3.75mv per cell per degree c difference from 25 degree c with the 25 degree c base charge voltage of 14.4v. also the battery temp is listed as being the averaged temperature over a 24hr period for the battery and not the ambient air temp. imho, you are fine.
  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Re: SunSaver MPPT Controller and Sun Xtender AGM batteries

    Thanks Bill and Niel!

    I will post any reply I get from Concorde here.

    Regards,
    Ole