One thing I noticed when I was running my battery down trying to reach the BB low voltage disconnect,, I was paying attention to my capacity monitor the whole time and when it got down to 12% soc I was actually looking at the monitor and all the sudden it dropped like a rock from 12% soc to 0% soc instantly.
At that point I started thinking that I must be close to the battery shutting down.
Nope , it took another hour and a half until the battery shut down , volts were 9.3 volts when the battery shutdown.
I'm not saying my monitor is correct just what I witnessed.