I got the warning when my battery was slightly under 15C (yes, C, not F). It's not in the firmware, it's in the Go App. I still have the 1.5 firmware.
I still wonder what's the minimum temperature you can fly full speed ahead with a cold battery. I keep an eye on the voltage, particularly when I flew with the warning on, and I know that the cut off where the battery shuts off is at 3.00V. The recommended minimum by DJI is 3.20V (saw it in an e-mail from DJI). I always try to keep it above 3.40V. I wonder if I can fly with a cold battery (say 15C) and as long as I'm careful not to let the voltage drop below say 3.40-3.50V, that I should be fine. Seems common sense, but I really don't know how LiPos behave in cold climates. Could it possibly go from 3.40 down to 3.00 in an instant (under some failure condition)?
Can't say it's exactly gradual under craft condition. DJI introduced a control to limit the power of the motors under cold situation, to avoid significant voltage drop under heavy load, especially if sudden. Not obvious to trust this graph as 100mA is not much, but you can already see the curve having some drop under 10C, lab condition. All that said with battery in good conditions. Also time factor as to what will be temp at start and internal temp will progressively increase.
Too many factors so buffer highly recommended!
Sent from my iPhone using PhantomPilots mobile app