Do you think this battery is safe for flying?

[apprentice]

Not really sure if this battery is still good or not.

I wanted to discharge the battery since I wasn't flying in the mountains yesterday because of a cloudy weather.

Since it was cold I wanted to warm up the battery first. Its initial temperature was below 15C / 59F but the outdoor temperature was around 3C / 37.4F. I took off and slowly flew on a very low altitude over the field 200 meters / 655 feet away and returned. I landed checked the battery temperature and it was 17.95C / 64.31F. This was a suitable temperature for flying.

This is the flight data on HealthyDrones.com. As you can see it says All good: no major deviations were found.
But then I took off again and started flying as I usually do. And this is the flight data from the second flight. As you can see I got several deviations on cell 1.

I was thinking why this happened. As you can see most of these deviations are at the end of my flight. At that time I was flying more aggressively. I was training landing like with an airplane and when the drone approached to me at the altitude of 10 feet I aborted landing and quickly ascended over the hall behind me. I then made a circle and repeated landing for several times. It looks like this is what was going wrong here.

But some more than a week ago this battery was doing great no matter that I had a very steep climb to the top of a smaller mountain. It was a 450 meters / 1476 feet climb to the peak of a mountain at 1259 meters / 4130 feet.

Do you think this battery is safe for flying?

 

[Mark The Droner]

If it was my battery, I'd continue to use it but I would not fly aggressively - especially towards the end of the flight. And I'd keep a close eye on cell balance. MHO

 

[apprentice]

If it was my battery, I'd continue to use it but I would not fly aggressively - especially towards the end of the flight. And I'd keep a close eye on cell balance. MHO

Thank you.

 

[alokbhargava]

Behavior of lipo batteries at low temperatures is unreliable. As far as you don't see any swelling on the battery and it's giving you enough flight time, you can use it.

Earlier times, few years ago, we never had an easy way to monitor cell to cell voltages but we used our batteries until discharge time reduced substantially. That worked all the times. I never had any issues.

Now we have better and easy ways to predict the quality of batteries and we have better batteries. If you are concerned, go for deep discharge cycle and see if it improves.

Your major issue right now is cold ambients. Warm the batteries before using them and ensure batteries are fully charged before flying.


Sent from my iPhone using PhantomPilots

 

[apprentice]

Behavior of lipo batteries at low temperatures is unreliable. As far as you don't see any swelling on the battery and it's giving you enough flight time, you can use it.

Earlier times, few years ago, we never had an easy way to monitor cell to cell voltages but we used our batteries until discharge time reduced substantially. That worked all the times. I never had any issues.

Now we have better and easy ways to predict the quality of batteries and we have better batteries. If you are concerned, go for deep discharge cycle and see if it improves.

Your major issue right now is cold ambients. Warm the batteries before using them and ensure batteries are fully charged before flying.


Sent from my iPhone using PhantomPilots

Thank you very much.