Schneider XW Pro SoC or Voltage?

Ganglefang
Ganglefang Registered Users Posts: 28 ✭✭
in Solar Beginners Corner #1

SoC versus voltage. I have seen conflicting comments in manuals and on the blogs. I have a new XP pro (replacement for an older XP +), New Discover Li-Ion with BMS, and MTTP dash 60s. When is the system controlled by SoC, and when is it controlled by voltage?


On-Grid
XW Pro 6848
MPPT 80-600 x 2
Discover 42-48-6650 Li-Ion x3
Generac 6730 20KVA
300-w panels x24
Closed loop


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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,883 ✭✭✭✭✭✭
    #2
    It is all in the Configuration and Firmware.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • Graham Parkinson
    Graham Parkinson Registered Users Posts: 165 ✭✭✭
    #3
    Not sure, but doesn't the BMS in the Discover AES batteries calculate SOC based on a very accurate internal voltage measurement? (Has to be accurate because of flat LiFePO4 discharge curve).  They may also incorporate a shunt for Coulomb counting as part of the SOC estimate, but I've never seen anything about this.

    My understanding is that in closed loop, the BMS derived SOC is encoded to the Schneider protocol in the Lynk interface and sent via Xanbus to the MPPT / Inverter to regulate the charging voltage applied. 

    Voltage sensing components in the MPPT and Inverter are not really sensitive enough to accurately control charging on their own and fully charge the battery.

    Offgrid in cloudy PNW

    Full Schneider system with 18 REC 420W panels, 100A-600V controller, XWPro, Insight Home, six Discover AES Rackmount 5kW batteries, Slimline enclosure, Lynk II, AGS, H650,  H2200, H3000, Kubota 4500, Onan 7500.

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  • Ganglefang
    Ganglefang Registered Users Posts: 28 ✭✭
    #4
    I think they use the shunt to calculate current, but I doubt if they count coulombs. I think the Schneider battery monitor might count coulombs, but it had a tendency to drift over time.  ==>synchronize.

    I THINK in a closed Loop, everything is controlled by SOC including the inverter and the mppt, although there is no SOC setting in the mppts.  I would like to get a hold of the Zen bus protocols, but that's not likely to happen.
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,883 ✭✭✭✭✭✭
    #5
    Modbus and Canbus maps for integrating battery BMS for Schneider Xanbus has been supported since 2017. The OP does not need this with AES LFP.

     Schneider does support Soc from MPPT and internal XWP chargers. You must have the right firmware in the battery, Inverters, mppts and Insight Cloud.

    If you need support, I can help. I charge a fee for a years support and it is guaranteed money back if you are unhappy. I spend many hours each year training and advising with the Schneider folks. Have field tested for Schneider most of their Inverter based products.  I use the Store here and support NAZ.  
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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