well i bought the excavator just under a year ago and i havent made any videos, but i found an old video from a previous owner.
the way its set up in the video is without any channel mixing. the way i got it now id say its a little bit faster and it will speed up when i use more than one channel.
in the video description he says he gets 3-4 hours of runtime, i never timed it but i probly get about 2 hours on it now... but the batteries came with the excavator when it was new.
so i guess a new battery would help.
https://www.youtube.com/watch?v=MZlacv4pztY