Never ever start a flight with a battery partly charged that also have been laying around for a long time, always charge your batteries before you fly.
I have done many times and have never had an issue. Having said that, many on the forums would probably warn against it out of caution. The risk is all yours to take providing you do it carefully.
Greetings from Ohio! New drone owner and am thrilled to join the MP family. I'm fortunate to have inherited a nice Mavic 2 from my dear friend Butch. And, since it's a Mavic 2 and it is 2026, you've probably guessed that I'm buying new...