Seplos 280 Mason 1% SOC at 55v pack?

[techstatic]

Hello,

My first time posting. I recently had some trouble while test loading my Seplos Mason 280.





Charging the pack though my Growatt SPF5000es does not work as it hits 3.5v setting on the monomer high voltage protection.
Does anyone have an idea what is happening?

Thank you in advance.

 

[wpns]

Check the individual cell voltages between your DVM and your BMS. Does the BMS require some kind of setup or calibration?

 

[Lt.Dan]

My bet is on a cell imbalance. Check individual voltages

 

[techstatic]

i had another seplos same model lying around for another pack and swapped it on the case, set it up with the same config and this is kind of ok.





I noticed the bus voltage on the first bms was low (10v)

 

[techstatic]

Check the individual cell voltages between your DVM and your BMS. Does the BMS require some kind of setup or calibration?

yes i was testing it for 2 days for loads less than 10amps, i started loading it with 30amps and 10mins into the test the battery went offline

 

[techstatic]

 

[Lt.Dan]

Have you calibrated the BMS yet? Putting in a new BMS and it all of a sudden showing 35%, does not mean it's correct. The BMS has no idea what the state of charge is until you calibrate it.

Charge the battery until it hits HVD, then discharge until it hits LVD.

 

[techstatic]

Sharing my resolution for this.

I sent my logs to Seplos and they instructed me to
1. tighten battery #6 - although I checked and it was quite tight already
2. then adjust the capacity back to 100ah, and fully charge the pack - i was quite hesitant at first because I am sure that the pack was up to 90% SOC already and it might over charge the pack. Nevertheless I went for it while taking voltages at the battery every 10mins

Eventually the battery voltage on the bms registered correctly and I am now able to pull 40amps continuously from this pack.

Thank you for your insights!