TB47's continually reporting to deep cycle

[Stinkys]

Hi all,

So I have a few batteries that repeatedly report that I need to 100% charge then drain to 5% or less. I have done this at least 3 times on one battery and I keep getting the same message. I am running firmware 1.5 and have updated all of my batteries and tx to this version, along with the latest iOS app.

Procedure I am using is 100% charge by turning on the batteries while they are on the charger to top them up, then fly down to 10% where power is gradually brought down and then keep feeding it power with gear down until it lands. The two batteries this morning that I attempted to cycle I got down to 2%.

Has anyone else had this problem?

 

[SteveT1]

You have discovered what DJI is trying to fix, displaying the correct percentage to calculate remaining battery and ultimately flight time.
You need to drop the cell voltage below 3.3v on each cell. BUT, not lower than 3.1 on each cell (you can damage the battery)
The battery will not shut down in flight so it is safe to just override the go home and keep it hovering close to ground.(about 6-8 inches off the ground) I just keep it up with the left stick until all cells are below 3.3v. At that point I let it land and after the battery have cooled down I charge it back up to 50% or so, where I keep it until next flight when I again top it up to 100% before flight.
Since you have already dropped it to 5%, I would fly it several more times before doing the battery calibration again. Minimum 5, better 10, to minimize the extra stress on the battery.

 

[Stinkys]

Right gotcha. Thanks for the info!

Since you have already dropped it to 5%, I would fly it several more times before doing the battery calibration again.

I am just concerned about this as I fly a lot over water. If the battery is still reporting that it needs a deep cycle does that mean it's not calibrated properly and it's possible I might have an auto-land scenario?
It looks like only 1 of the 2 remaining batteries have this notification now so I will put it aside for over land use only. But clarification would be good for future reference.

 

[SteveT1]

I don't think it is an issue, it is just the fact that the calculated battery percentage is incorrect. So, I wouldn't stretch it. Battery may have less than expected. If you are not stretching, you will be OK. If you are, over land is a good idea.