Battery error

Battery Error.....Ok this is the story....Yesterday I used battery 1 no issues getting the Little Dragon ready to break his record. I put Battery 2 in and did the normal testing ,looks good so I climb to the target 300ft...beating 217......I was up getting some great video of the sunset...and boom WARNING Critically low battery....yes I freaked ...I looked at the screen and battery was 100% ..with 75 left and 3.9 ,3.8 cells....still brought LD down quickly . Checked again and everything looked good, so I said lets hover ...battery had no more issues. Now today the battery 1, the one that had no issues , started with issues ! the first thing I notice was my settings on my bottom buttons were NOT the same and then the battery error showed up (not Critically Low ) just battery error... SO I JUST SAID HELL NO NOT WORTH THE RISK and I brought him down.I also notice that all the setting I put on the camera were change too and I couldn't adjust them.So I turn everything off and back on and everything went back to norm but sill got a error twice.So I decided to just hover in the garage to wear down the battery .Now I am dropping it down below 5% and will charge it again 100%...Maybe the firmware didn't take.....any thoughts please report back Thanks The Dallasfreak...could not get below 6%