When flying last week, after three or so flights, the RC handset kept beeping and flashing the RED light even once the drone was turned on. The status bar on the APP was flashing red, and saying something like "battery cell error" I shutdown the craft and tried a new battery, this time the app showed no problems, but the controller was still playing up. Once I started the motors the controller went normal. I was obviously spooked as the battery seemed fine in the battery monitor, and I started to suspect that the cell may be knackered in the RC.....? Either way I flew all day with no issues, sometimes the red light and beeping would continue after the drone was on, sometimes not, (it isnt the no connection beep, the frequency was different) And I flew the battery that supposedly gave the error n the craft, it gave no further error, and flew fine. Any ideas?