Dudanation

I finally solved this issue. It was the wires to the batteries and probably the wires from the busbar to the inverters. All were of random lengths. The longer wires listed 70mm² on the insulation while the shorter ones were 2 AWG but it turns out the 70mm² was fake. When I cut everything out, it was smaller than the 2 AWG. I ran new 35mm² cables of equal lengths for all of the batteries to the busbar and 70mm² cables of equal lengths to the inverters. All quality tin-plated copper.
I can now charge up to 30KW as expected (70A for each battery limited by the BMS, 100A is the maximum limit but BMS won't allow it and that's fine). I discovered the problem by throwing a DC ammeter onto the closest battery and saw the limitations from when that battery hit 50A. Clearly, it was telling the inverters not to deliver more power and all the other batteries got less than 30A. As that battery went up with SOC, down went the amps. I was chasing inverter problems but it was a BMS issue caused by the "professionals" who installed the system. I knew the wires were not exactly the same lengths but didn't know the big cables were so small. And glad I cut it all out and went fresh because I initially ran all the math to figure how much length to add to each wire and man I would have been pissed at the result not being resolved much.
Batteries required a full drain to get their SOCs fixed too. They were way off, obviously. But even going to full charge and balancing was still way off. Still had to do a full deep cycle to get all of the capacity back. Urgh!

Also, at the start of this thread I apparently only had 3 inverters. I now have 4.

I finally solved this issue. It was the wires to the batteries and probably the wires from the busbar to the inverters. All were of random lengths. The longer wires listed 70mm² on the insulation while the shorter ones were 2 AWG but it turns out the 70mm² was fake. When I cut everything out, it was smaller than the 2 AWG. I ran new 35mm² cables of equal lengths for all of the batteries to the busbar and 70mm² cables of equal lengths to the inverters. All quality tin-plated copper.
I can now charge up to 30KW as expected (70A for each battery limited by the BMS, 100A is the maximum limit but BMS won't allow it and that's fine). I discovered the problem by throwing a DC ammeter onto the closest battery and saw the limitations from when that battery hit 50A. Clearly, it was telling the inverters not to deliver more power and all the other batteries got less than 30A. As that battery went up with SOC, down went the amps. I was chasing inverter problems but it was a BMS issue caused by the "professionals" who installed the system. I knew the wires were not exactly the same lengths but didn't know the big cables were so small. And glad I cut it all out and went fresh because I initially ran all the math to figure how much length to add to each wire and man I would have been pissed at the result not being resolved much.
Batteries required a full drain to get their SOCs fixed too. They were way off, obviously. But even going to full charge and balancing was still way off. Still had to do a full deep cycle to get all of the capacity back. Urgh!

Also, at the start of this thread I apparently only had 3 inverters. I now have 4.

I finally solved this issue. It was the wires to the batteries and probably the wires from the busbar to the inverters. All were of random lengths. The longer wires listed 70mm² on the insulation while the shorter ones were 2 AWG but it turns out the 70mm² was fake. When I cut everything out, it was smaller than the 2 AWG. I ran new 35mm² cables of equal lengths for all of the batteries to the busbar and 70mm² cables of equal lengths to the inverters. All quality tin-plated copper.
I can now charge up to 30KW as expected (70A for each battery limited by the BMS, 100A is the maximum limit but BMS won't allow it and that's fine). I discovered the problem by throwing a DC ammeter onto the closest battery and saw the limitations from when that battery hit 50A. Clearly, it was telling the inverters not to deliver more power and all the other batteries got less than 30A. As that battery went up with SOC, down went the amps. I was chasing inverter problems but it was a BMS issue caused by the "professionals" who installed the system. I knew the wires were not exactly the same lengths but didn't know the big cables were so small. And glad I cut it all out and went fresh because I initially ran all the math to figure how much length to add to each wire and man I would have been pissed at the result not being resolved much.
Batteries required a full drain to get their SOCs fixed too. They were way off, obviously. But even going to full charge and balancing was still way off. Still had to do a full deep cycle to get all of the capacity back. Urgh!

Also, at the start of this thread I apparently only had 3 inverters. I now have 4.

I finally solved this issue. It was the wires to the batteries and probably the wires from the busbar to the inverters. All were of random lengths. The longer wires listed 70mm² on the insulation while the shorter ones were 2 AWG but it turns out the 70mm² was fake. When I cut everything out, it was smaller than the 2 AWG. I ran new 35mm² cables of equal lengths for all of the batteries to the busbar and 70mm² cables of equal lengths to the inverters. All quality tin-plated copper.
I can now charge up to 30KW as expected (70A for each battery limited by the BMS, 100A is the maximum limit but BMS won't allow it and that's fine). I discovered the problem by throwing a DC ammeter onto the closest battery and saw the limitations from when that battery hit 50A. Clearly, it was telling the inverters not to deliver more power and all the other batteries got less than 30A. As that battery went up with SOC, down went the amps. I was chasing inverter problems but it was a BMS issue caused by the "professionals" who installed the system. I knew the wires were not exactly the same lengths but didn't know the big cables were so small. And glad I cut it all out and went fresh because I initially ran all the math to figure how much length to add to each wire and man I would have been pissed at the result not being resolved much.
Batteries required a full drain to get their SOCs fixed too. They were way off, obviously. But even going to full charge and balancing was still way off. Still had to do a full deep cycle to get all of the capacity back. Urgh!

Also, at the start of this thread I apparently only had 3 inverters. I now have 4.