Honestly, vague title because I'm unsure where to even begin. We've been parked for a few days in Yellowstone National Park in the US. Historically we run 5-6 days on batteries alone (setup details below). Recently I completed a solar setup that I 'thought' was working well, or maybe currently think so? I'm not sure. After 2 days of being parked at Yellowstone in a relatively shady spot and arriving with full SOC of 14.59V on the Battle Borns, 'something' tripped in the system and shut me down. The Multiplus had a low battery alarm, the BMV showed 57% and something like 13.35V. The SmartSolar controller said that the battery voltage had dropped to 9.12V which is obviously well below anything a LiFePo4 battery should ever see. This tripped the battery guard, took me a little bit to locate the failure, initially thought it was the transfer switch because I've had a few issues with that. The battery guard appeared to have done its' job, albeit at the cost of the battery guard as the only way I was able to restore power was to bypass it. No apparent temperature issues, outside temp was 84F and inside the trailer was probably 78ish. Batteries are inside, under the main bed.
Fast forward another 30ish hours, we went to bed and night temperatures drop fairly rapidly. Around 1:30 am my wife woke me saying it was too quiet, she couldn't hear the fridge running. Pulled up the BMV app, it wouldn't load. Checked the screen of the device itself and it was shut off. Inverter was completely off despite being in "ON" position. Silly me, left the multimeter at home so I didn't have a way to manually read the voltage. First thing this morning, we packed up and left Yellowstone to run some errands including buying a multimeter as well as dump/fill the Airstream. Once solar started kicking in around 8:30 am, we started getting some intermittent functionality of 12V users as one would expect. The BMV eventually turned itself back on with a voltage of 13.05V, so not "actually" a low voltage or even 0% SOC. Air temp was chilly last night but not "that" chilly considering the batteries are inside, outside was in the 45-50F range while we were probably 55-60F inside.
As we speak, we're in an RV park outside Yellowstone connected to shore power to get a full charge all over again, but more importantly for cell service to connect to you guys and try to troubleshoot something. I've attached some photos as well - apologies in advance for the kabalsalat! I've tried cleaning up a bit, but definitely have room for further improvement.
Just not even sure where to begin troubleshooting because readouts have been looking normal despite the weird events. Solar this morning was 50ish watts in our shady spot in Yellowstone, ramped up to 515 watts or so once the day got a bit later and we were outside the park. Currently plugged into shore power and charging batteries at 1200W. Are there additional historical logs I can pull from either the BMV or the SmartSolar? The app-based readouts are pretty basic.
A bit about my system overall:
2003 Airstream
960W renogy panels, 6 x 160W each hooked up in Series-parallel configuration (two sets of 3 panels in series, then paralleled into the MPPT)
800 Ah BattleBorn batteries, 8 x 100 Ah each
BGA-225 battery guard
Multiplus 12/3000/120-50 120v VE Bus
Victron SmartSolar Charge Controller (150V 45A Tr)
BMV-712
Go Power! TS-30 30 Amp Automatic Transfer Switch (shore power & battery charge primary, secondary is from the inverter)