Possible grounding issue ?

I constructed a 232 cell, 8P x 29S EV cell pack. Made from wood to keep it light. 4 cases each holding 60 cells. The last holds 52. This totals 118v @504 A. I am using a 500A 29S DALY BMS. From the first try, I could never activate the BMS. Eventually sent it back to DALY for them to diagnose. No damage, they just reset some params. It now activates at every attempr to charge my pack. I have a preset OBC that delivers 118.9v @58A. My DALY BMS displays widely varying currents at 10x that which the OBC can provide. It is never stable. DALY claims there is interference that causes this. They cannot make their BMS charge my cells. I see no interference when I scope out the OBC output. I now believe there needs to be a car chassis ground here somwhere, most likely at the negative end of the OBC that feeds the cells/BMS. Comments are appreciated.

Not sure if you managed to solve in the meanwhile. I had about the same problem with a DALY 500A in a 32S Li-Ion configuration with the BMS showing random statistic values. I had the battery pack in a closed environment with high frequency inverters for brushless motors that I think were causing some kind of interference, I managed to partially solve by shielding the BMS wires to the battery common negative ground.
I said "partially" because that never really solved the problem, I ended up by trashing the DALY and building a custom BMS for that particular application.

In your case could that be your charger with some serious ripple on the output line?

Noday said:

Not sure if you managed to solve in the meanwhile. I had about the same problem with a DALY 500A in a 32S Li-Ion configuration with the BMS showing random statistic values. I had the battery pack in a closed environment with high frequency inverters for brushless motors that I think were causing some kind of interference, I managed to partially solve by shielding the BMS wires to the battery common negative ground.
I said "partially" because that never really solved the problem, I ended up by trashing the DALY and building a custom BMS for that particular application.

In your case could that be your charger with some serious ripple on the output line?

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Thanks for your reply. I did try both shielding and grounding with no effect. DALY tried to tell me it was my OBC. It charged my cells with a stable current without the DALY in circuit. Since I cannot find another 500A BMS, I plan to REWIRE my cells from a 29Sx8P to 2 separate 29Sx4P strings. I can find a few 30S 250A BMS'S. Since my OBC is actually 2, 3300w supplies in parallel, I will separate these into 2 SEPARATE chargers. I sent my DALY back to China to have them 'fix" It. They REPORTED there was nothing wrong / damaged. They reset a few parameters and that did not cure the problem either.