OgreMustCrush
Only 1 panel shattered so far
I think I have a possible theory why the voltage spiked. There are 2 different registers available over RS-485 that appear to refer to the overvoltage protection voltage, though the names/descriptions are ambiguous as to which is the actual overvoltage protection limit that shuts down charging. Anyway, the BatChgLimitVolt was at 57.6 while the BatOverVolt one was set to 60V. Think it might have gotten set that way when I was debugging the RS-485 communication and trying to figure out which values actually work or do anything, that register might have gotten sent invalid data and defaulted to that value. Given its name, maybe it isn't actually an overvoltage protection voltage but rather an "overcharge" voltage. Anyway, I dropped it both it and the other one down to 56V just to be extra certain it doesn't happen again. Neither of those are exposed in the UI, and as far as I can tell the BMS doesn't affect them either.

That's a good suggestion; I haven't actually tried changing that charging current logic setting yet. It presumably should default to something when no BMS is connected, I wonder what scheme it uses it that case. The Inverter one seems like the one that is the most ambiguous of the 3 options though, at least the HMI logic tells you it uses the maximum charge current in the Battery Manage screen, and I can see exactly what the BMS is requesting on a second to second basis, but I don't know what algorithm the "machine's derating logic" uses.
I'm not asking anyone to solve an issue with my setup, I'm working through that myself just fine, more providing feedback about what I am seeing and asking if anyone else has seen anything similar. Haven't seen anyone else post any end-of-charge voltage/current plots w/ from an HESP since I brought this up yet. Would love to see a nice clean one with no cycling so I can find out what at least one set of known good settings are.

Did you try it in Inverter Logic with the BMS set to Disable to see how it performed with some sun in that case?
That's a good suggestion; I haven't actually tried changing that charging current logic setting yet. It presumably should default to something when no BMS is connected, I wonder what scheme it uses it that case. The Inverter one seems like the one that is the most ambiguous of the 3 options though, at least the HMI logic tells you it uses the maximum charge current in the Battery Manage screen, and I can see exactly what the BMS is requesting on a second to second basis, but I don't know what algorithm the "machine's derating logic" uses.
Yeah, I get that, I did something similar with my old inverter for a while before I finally found the magic settings where BMS comms didn't mess anything up. But Solar Assistant's support for this inverter is really poor right now, most of the inverter settings are missing and half the ones that are there don't work, so I can't really rely on it to automate anything. I'm probably going to eventually move to doing my automation through Home Assistant once I have a robust enough RS-485 monitoring/control solution setup for this inverter, but until I get to that point, I'm limping by with the inverters built in features which requires it to know SoC to do anything useful.I do not know your system, something I learned after 3+ years with Growatt AiO, I stopped using BMS closed circuit with the AiO, went to BMS to the SA (solar assistant), changed the AiO to US2 Lithium no BMS and closed circuit of the AiO to SA. it stopped all the fighting between the AiO and BMS batteries.. letting SA be the man in the middle (hub) so to speak. Everyone is happy including myself.. I see better management and control of the batteries and operation of the AiO..
Now it may not be for you.. but just wanted to share something, you may consider.. wish you the best.
I'm not asking anyone to solve an issue with my setup, I'm working through that myself just fine, more providing feedback about what I am seeing and asking if anyone else has seen anything similar. Haven't seen anyone else post any end-of-charge voltage/current plots w/ from an HESP since I brought this up yet. Would love to see a nice clean one with no cycling so I can find out what at least one set of known good settings are.