Thanks. That video appears to be a video done by a fellow DJI pilot - I’m not sure if we can call it “the DJI battery video.” It appears to be a good informative 32 minute video, however. It would have been helpful if you had included the area in the 32 minute video that you claim had discussed that a deviation of more than .01 v indicates something is “amiss.” I believe I found the cell balance area of the video you’re referring to at the 11:40 mark. He discusses that you should be concerned with a .1 volt deviation. I mentioned this in my post above. I cannot find anything that says you should be alarmed with a .01v deviation or a .02v deviation. It appears you are mistaken as I pointed out in my previous post.
I have to say, I’m perplexed as to why you’d post the video and request me or another member to find this information re cell deviation for you and give an explanation when in fact it shows you were mistaken from the start as hinted in my post above and no explanation was needed. All you had to do was pay attention to the video or check the video a second time after being alerted in my post. You could have saved me or somebody else a lot of time by simply watching and listening more carefully to the video. There is nothing wrong with the info in the video that I can see. The problem is elsewhere.
RE the AC FW version, my understanding is there are P3 batteries out there in this world that like to shut themselves off mid-flight when they are launched cold. This problem was mostly “fixed” in a battery upgrade some years back. So a battery FW upgrade can help solve the problem, although it’s still never a good idea to launch a battery cold, and it’s still possible for a battery to shut off when cold. A current AC FW recognizes an older and outdated battery FW version and therefore alerts the pilot that a battery FW version update is needed to certain older FW version batteries and not needed to other later FW batteries. So that is a good reason to upgrade the battery FW. There may be other good reasons too. Re battery temp, in cold weather, I personally like to launch with a battery at least 20C but I actually much prefer 25C+. My understanding is a battery operates most efficiently with a battery temp in the range of around 30C - 35C.
Good luck.