SW4048 bulk charge voltage

fasterskiifasterskii Registered Users Posts: 6 ✭✭
I've been trying to figure this simple (i thought) configuration change since i got my Volt battery modules. I see that the manual specify that bulk voltage could be set as low as 40.8 . I need it to be set around 48 v to support charging the batteries. When I try to do that I get a message that the  value is invalid. Lowest it accepts it is 57.2 . In the manual the only thing I can find is the following generic clause.
I have the battery type set to custom. Put the inverter in standby. Nothing seems to be working for me. According to the battery guy this is doable as his other customers are able to do this. Im running the latest firmware (3.11) . Thanks in advance for any insight into this.

Bulk Voltage-> Sets the bulk voltage for a custom battery type. See note below.

"NOTE: If a warning is received indicating that a setting is not accepted by the SCP, gradually increase the value of the setting until the SCP accepts it. This type of warning means that an internal minimum threshold value is being crossed and therefore the setting cannot be saved."


Comments

  • littleharbor2littleharbor2 Solar Expert Posts: 1,449 ✭✭✭✭
    edited November 27 #2
    What type of battery are you charging that wants only 48 volts in bulk/absorb? If flooded lead acid, you're very likely going to want  more than   57. 2. 

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • fasterskiifasterskii Registered Users Posts: 6 ✭✭
    What type of battery are you charging that wants only 48 volts in bulk/absorb? If flooded lead acid, you're very likely going to want  more than   57. 2. 
    it is chevy volt module, 12S configuration.
  • littleharbor2littleharbor2 Solar Expert Posts: 1,449 ✭✭✭✭
    Technology beyond my level of understanding.  I will continue to follow this thread.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • EstragonEstragon Registered Users Posts: 4,283 ✭✭✭✭✭
    I don't know this gear at all, but what is the float voltage setting, and assuming there is one, the rebulk setting? 

    Just a WAG that it may not be the absolute value of the Vabs that 's causing the error, but maybe a relative value (eg throw exception if Vabs < Vfloat)?
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • fasterskiifasterskii Registered Users Posts: 6 ✭✭
    Estragon said:
    I don't know this gear at all, but what is the float voltage setting, and assuming there is one, the rebulk setting? 

    Just a WAG that it may not be the absolute value of the Vabs that 's causing the error, but maybe a relative value (eg throw exception if Vabs < Vfloat)?
    Float can only be set to 50 V. According the the manual for the sw4048 it should be able to be set down to 44 V. I'm thinking that they have changed those minimums in one of the firmware release after the manual was written.
  • EstragonEstragon Registered Users Posts: 4,283 ✭✭✭✭✭
    Possibly.  I can't think of a good reason to limit it in firmware post-production, but there's no rule saying it has to make sense to me.  OTOH, I wouldn't rule out another setting that lower limits Vabs and Vfloat (rebulk, LBCO, etc)..
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • fasterskiifasterskii Registered Users Posts: 6 ✭✭
    Estragon said:
    Possibly.  I can't think of a good reason to limit it in firmware post-production, but there's no rule saying it has to make sense to me.  OTOH, I wouldn't rule out another setting that lower limits Vabs and Vfloat (rebulk, LBCO, etc)..
    that is where my head is at as well. Especially that i'm told this can be done on the same hardware by others.
  • boBboB Solar Expert Posts: 969 ✭✭✭✭
    edited November 28 #9

    Try running the SW at the lowest battery voltage you expect and see if it will regulate and not shut off due to low battery, LBCO.

    You might want to do this under load as well which will drop the battery voltage a wee bit more when it gets to a lower state of charge.


  • fasterskiifasterskii Registered Users Posts: 6 ✭✭
    boB said:

    Try running the SW at the lowest battery voltage you expect and see if it will regulate and not shut off due to low battery, LBCO.

    You might want to do this under load as well which will drop the battery voltage a wee bit more when it gets to a lower state of charge.


    There is no issue running the SW on those batteries. Runs like a champ down to 41.5 to 42 volts (i do not want to go any lower at this point).

    The only challenge is the chargin voltages . According to the manual and what others have been able to do I should be able to configure it for lower bulk voltage. That is not the case with my unit. So I'm trying to see if anyone can shed the light on this based o nthe knowledge and experience they have.
  • boBboB Solar Expert Posts: 969 ✭✭✭✭
    edited November 30 #11
    What is the software revision of your SW ?     4.x something ?   Or earlier ?
  • fasterskiifasterskii Registered Users Posts: 6 ✭✭
    boB said:
    What is the software revision of your SW ?     4.x something ?   Or earlier ?
    latest 3.11 there is no 4.x as far I can tell.
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