So, it is an old battery, roughly half of its useful life left, you bought from Joe, never allowed it to balance, and ran it nearly dead, on the first night of a long trip. This information should have been in your very first post.
My guess is that your 30% is closer to 10%, and that is one reason this info was not in your first post. No, I do not know this for certain, but this is an estimate based on long experience. With humans not wanting to admit they screwed up, that is.
Did you pee directly into it or have it run over by a bus, as well?
You almost certainly have a severely depleted group, likely more than one, reviving the BMS likely to be only the most temporary of solutions. Charging fully and leaving on charge for several days or more seems not currently feasible during trip, tear down and charging individual strings another way, however, age, vendor, usage pattern, and abuse may render recovery efforts of questionable value.
You may get "lucky", and it is just a BMS lvc shutdown, primarily, but this will likely just mask the depleted series strings which are very likely to be present.
The battery shut itself down at the end of day one, didn't it? Because if you are saying it was fine when you parked it, and then suddenly failed the next morning, that would indicate a completely different problem, which is really quite extremely unlikely, what is much more highly probable is that you ran it to shutdown, knew that was a bad thing, and did not want to admit to it, thereby leaving out crucial information which is necessary to solving your problem.
