Well, glad to hear we have one problem off of the list for you.
If you have a battery imbalance on your TB55s, you could consider just leaving the M210 turned on until the batteries get themselves to an equal level (props off for safety). Its possible that they just did not get charged up to the same level on your charging hub - or that if its brand new and you did not charge them prior to setting this up they just arrived to you at different enough levels that the M210 does not like the difference in their voltage.
Also, you could leave both batteries on the M210 until they get discharged far enough to put them on your charging hub and take them both back to 100%.
One thing to be careful of is that the batteries (for example just one of them) can fairly easily get moved in the hub just enough so its stops charging. That leaves just one getting to 100% and the other one probably too far away from 100% for the M210 to be happy and let you fly.
Remember to keep your monitor and remote controller battery charged up just to make sure you do not get any unexpected battery messages related to those 2 items.
Going back to the imbalance question, were you able to see the 2 battery's charge level in the app? If not, check it out and let us know where they are at (assuming you get the problem again).
One last thought. Depending on your battery discharge settings and the length of time they have been charged, they could have started self discharging too - maybe one before another creating a gap in their voltages.
It could be none of these suggestions are the answer, but they are all things you can keep an eye on to make sure you don't get that warning again.
Michael
