Nope. the battery was fine, no issues visible. I’m using a Mauch power module, so the current and voltage readings are quite accurate.
And I had a look at some of the previous flight logs of the same plane. There sometimes was a tendency for similar behavior (i.e. - nose heaviness) that was visible. This was not as high as seen here though -
As you can see, the Des_pitch was peaking, but was not continually demanding the highest value as seen in the crash here -
In some of the flights, the behavior was very good and there was no significant change between desired and actual pitch values. -
In the process, I also noticed one more anomaly. -
The CH1 output was not around the trim center,it was applying left Aileron. which implied that there was a natural tendency for the plane to roll right. This was not observed in any of the previous flights however. I don’t know what might have caused this.
So, I suppose that both of these issues caused the plane to enter an unrecoverable stall.
Thanks, @lowlyelevated and @hunt0r for all the help!