Here's how things went:

I spent a Saturday night capturing M106 with lots of technical problems as I'm still learning meridian flip, polar alignment, flats, NINA, testing battery consumption, etc. I chose my parents farm as the sky's were slated to be clear and they are in a bortle 4 zone about an hour and 15 mins east of me.

I setup around 8:30pm with a side plan of testing the limit of my dual battery setup. I originally targeted M101, but I could not see it in preview (found out later I was doing polar alignment wrong, not plate solving or centering after plate solve in NINA), so I retargeted to M106. It was not centered (second hint that polar alignment process was wrong). I went ahead and manually centered instead of remembering plate solve and center.

This was only my 6th shoot after all. First was B/W success of half dozen images and I got lucky on the polar alignment working out. 2nd was failure due to target/guiding/cloud/PHD2 calibration issues. 3rd was failure due to clouds rolling in 15 mins into shoot. 4th was my first post on Astrobin and first color integration. 5th was targeting failure (same issues as above).

Forgetting that I had setup my sequence in NINA for M101, I started the sequence around 9:30pm and checked every couple hours to see if things were tracking. Everything seemed to be going well through midnight, so and set alarm for around 2am ahead of the meridian flip.

I had tested auto meridian flip the day before because I could never get it to trigger in NINA. Turned out that the mount limit protection had been halting things a few degrees before the NINA limit was reached. Having resolved that issue the day before, I headed out at 2am to see it in action on a shoot.

The flip went as advertised, but when I checked the first image to follow, I found that M106 was nowhere in frame. That's when I noticed the sequence was still set to M101. I paused the sequence, slew to M106, and thought I had restarted it. Turned out that a new sequence got created (with one sub). I clicked play and walked away...

My dad (who is an early riser) woke me up at 5am and asked how everything went. I said it was going great and decided to go check on the shoot. I was sick when I found that the second sequence had finished after it's one frame. At first I thought the original sequence was lost, but I found it in the sequence list and realized everything had been paused since the 2am flip. I previewed and saw that M106 was still being perfectly tracked, so I continued with the sequence.

At this point, all L and R subs were complete, but only two G subs. I had set the sequence for 30 of each filter. I resumed the sequence for G, not realizing that I only had an hour of target time left. As I walked into the house about 50 yards away, I realized this and went right back out. I calculated I could get 6 or 7 of G and B. I paused the sequence after the 6th G sub and turned that lane off. Kicking off the B series, I checked my dual Celestron PowerTank battery levels. I use one for the mini computer and WIFI and a second for the rig itself. The dew heaters had been kicking in pretty hard for the last half of the night and it was starting to hit critical level on the rig battery. Now I was worried the B subs would not make the half hour needed.

Eeking out the 7th B sub, battery was no longer able to provide stable power. I shut down the sequence and moved the rig over to share off the computer power pack to get flats, dark flats, and home the mount and focuser. By this time, the second battery was about drained. By now, I had been running off battery for over 9.5 hours. I had estimated getting up to 12 hours without heaters, so this was good. Temps bottomed out at 27F during the latter part of the shoot.

Reviewing everything, I have since learned what I was doing wrong with polar alignment, I know to recheck my sequence target, and I know my target time on battery should be estimated at 8 hours with heaters, 10 hours without. I also found that I did not have plate solve turned on or center target post slew in NINA. I expect that might have helped a bit, eh? I am anxious to get another clear night to test targeting pre and post meridian flip and to tune all these other things I found amiss.