Problem rec bms shutting down due to low voltage at 3v fix


  • I\'m trying to clear this bms bug up. Problem is set to low voltage cut off to 2.5v and have tested at 2v and no change from bms still bms shut off at 3.+ volts no matter the change. I have a snapshot of my active bms. Not below 3v a cell. Rec bms still kicks the relay. I have 780 ah available. 25kwh available still bms still cuts off.   My setup consists of 48 cells in a 16s config. Lifepo4 winston cells.    


  • This above is with a approximate 20 amp draw. Want to mention this is a SI SMA SETUP.   Batteries in this 16s x 3 config can handle easy 390 amps all day and 3 sec runs at 7800 amp pulse draw. Sunny island flashing cell low voltage shutoff. This is what trips the relay. What am I missing 😕

  • Without knowing which firmware you are using check the setting from RE1L and CLOW.

  • I had a quick look over your pics.  Nice that you included them.  I see that you have your low voltage hysteresis (deadband) set to what looks like 1 V.  The is the RE1L parameter that Ben is referring to above.  Try setting it to about 0.1 and it should help.  I would also look at lowering my Max voltage hysteresis down to about 0.2V as well. I put together a voltage control chart showing which parameters control each function that might help too.  Attached below Hope that helps, Rick

  • Yes back to coffee ☕️ in the morning. Sweet Rick that fixed the problem. RAZL 0.25 RAZL? SHOWED .1  
    1. Please re-up voltage perimeters control chart. Shows error when trying to open.
    2. Thanks again Rick and Ben! This setup is starting to run like a well oiled machine! This bms has been a learning curve but looks like its becoming a well made solution for the sunny islands. Inverters have crappy batteries manager for lithum batts. But..... with the rec bms crazy lots of control and I\'m really happy to know I have full control of my batteries!
    I included a picture of the error I was getting on the SI\'s and this did pertain to a e3 red light error incase anyone else runs into this problem like I was running in to. 👍 👍

  • @Clarence 

    Hey Clarence, we lost your pics when we moved to a new platform and have some users asking to see them.  If you can find them, it would be great if you could post them again.  And any others that might be of interest :)

    Thanks, Rick


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