XW6848/Batt monitor -can you calibrate battery voltage?

jtdiesel65jtdiesel65 Solar Expert Posts: 223 ✭✭✭
Both read the same, but 0.2-0.3v from actual. Is there a way to calibrate the battery voltage readings?

I looked all over, but haven't found any setting.

thx

Comments

  • MichaelKMichaelK Registered Users Posts: 203 ✭✭✭
    I think the real problem is which reading is accurate?  Your voltmeter reading, or the battery monitor.  The problem is no-one really has a calibrated voltage standard, so if your volt meter says "25.5V", how do you really know it is actually 25.5V?

    If you take three different brands of meter and they all read 25.5V, you can suppose that 25.5V is accurate.  But suppose you read 25.4V, 25.5V and 25.6V?  Do you just take an average?
    System 1) 15 Renogy 300w + 4 250W Astronergy panels,  Midnight 200 CC, 8 Trojan L16 bat., Schneider XW6848 NA inverter, AC-Delco 6000w gen.
    System 2) 8 YingLi 250W panels, Midnight 200CC, three 8V Rolls batteries, Schneider Conext 4024 inverter (workshop)
  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    The other issue can be--In times past, some brands/models would report the temperature corrected value (i.e., Battery voltage is 14.8 volts on device, but really 14.4 volts because the remote battery temperature sensor is reading a high battery bank temperature and backing down on the actual charging voltage...).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jtdiesel65jtdiesel65 Solar Expert Posts: 223 ✭✭✭
    Thanks. I was thinking with regard to setting absorb voltages to the same between charge controllers and the XW. I can adjust the absorb set points up or down based on what each device reads, but I thought maybe being able to sync the resting voltage readings would be a good starting place.

  • Dave AngeliniDave Angelini Solar Expert Posts: 5,910 ✭✭✭✭✭
    Schneider has 2 different tools for the XW system. Maybe more as they do not tell all ;)

     The Configuration tool which one can buy, is for AC calibration of multiunit systems, for cluster systems of 3 phase and XWPro Rule 21 etc. Installers mainly need this tool.

     The other tool that is not for sale is the Cal Tool. It is for people doing field testing/circuit validation as I and others do for them. It is also for rare cases that they think something needs to be adjusted. The Cal tool allows access to every DAC setting in an XW and is basically the production line standard of their settings. There is a DAC range, and one can tell if a unit is not centered, typical of the production run or historical data. It is a Quality Assurance tool at that point in manufacturing.

    If you got a case number for a warrantied XWP,  I would bet they tell you the DC is in the range of normal for XW system. The exact DC value is not that important, as long as it is in the specified range. There is some small error.

    XWP is also the generation of XW that is Soc based and all of that data comes from a BMS, can or modbus, or your network battery monitor. It can do all kinds of grid things based on Soc, shift it's output frequency based on Soc for AC coupling offgrid or microgrids, and a few other strategies that hurt my head living offgrid. 

    "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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