Mavic Air Battery Issues

[buddukes]

I purchased my Mavic Air in April. I have the low battery warning setting set at 20%. Twice (a couple of weeks ago and last night) I have had the battery reach 20%, the drone begins to return home, tells me I only have enough battery to return home, and then immediately jumps to 0% (from 18% the first time and from 15% last night) and starts coming down rapidly...almost a free fall the first time - thankfully I was able to get the drone over grass before a hard landing. After these instances, neither battery will charge and the green LED indicators don't light up at all when pressing the button on the battery. When I put either battery on the charging hub that came with the Fly More kit, the LED indicator turns Red after a few seconds. Has anyone else experienced anything similar? Now two of my three batteries are inoperable. This is my first DJI product experience. Anyone from DJI on the forum who can provide guidance on how to remedy this? Thanks!

 

[tcope]

I'm guessing you let the batteries cool down?

Will the batteries turn on at all? Connect them to the charge and attempt to turn them on.

The unwritten rule is that you should be _back_ at your landing area at 30% battery.

I cannot speak to the 15% down to 0% jump. Perthaps if you have done this several times the battery had become damaged.

When a lipo battery reaches a very low state of charge it easily becomes damaged. If you are ourt flying at 15% and it's still returning back, you could have very well have damaged the battery, especially if it starts to auto land at 0%.

 

[buddukes]

I always let the batteries cool down before charging. The batteries will not turn on at all. I have attempted to connect to the charger and press the button on those two batteries...nothing happens as far as the batteries are concerned, but the LED indicator on the charger turns red. In both cases I was very close to my landing area when the 20% battery alert came on and that is generally how I operate. The jump is what was shocking to me as I was close to the landing spot and just let the drone take over with Return to Home...but then it went from 18% and 15% to 0% on the two batteries instantly. And afterward on each battery, neither will charge or turn on. I have two Parrot drones and have never seen that behavior before.

 

[tcope]

The batteries may have become damaged... it's difficult to know without some background on your prior flights.
to msingers site for more info:

DJI Flight Log Viewer

 

[buddukes]

Attempting to upload logs for the two flights. Easy to see near the end of the flights where the battery instantly jumps from in the teens to 0%.

 

[tcope]

First, if you don't have your battery voltage displayed, turn it on in the settings. This is what you need to watch.

The percentage is a guess by the software. If you look at the voltage of the cells they don't change that much (3.586 at 12% and at "0%"). I suspect once the voltage is as low as it was that the software may not report a very accurate number. This is another reason why you should be at the landing area around 30% and landing between 30-20%.

Also, you started at 96% and 95% battery. What was the situation behind this? Is that right after charging it? I'm not sure if it will help but you might want to charge that battery to 100% and then turn it on and charge it some more.

 

[buddukes]

First, if you don't have your battery voltage displayed, turn it on in the settings. This is what you need to watch.

The percentage is a guess by the software. If you look at the voltage of the cells they don't change that much (3.586 at 12% and at "0%"). I suspect once the voltage is as low as it was that the software may not report a very accurate number. This is another reason why you should be at the landing area around 30% and landing between 30-20%.

Also, you started at 96% and 95% battery. What was the situation behind this? Is that right after charging it? I'm not sure if it will help but you might want to charge that battery to 100% and then turn it on and charge it some more.

I keep the batteries on the charging hub when not in use, so they should always have a full charge when I start (is that bad?). I have noticed more than once that it seems I start off at about 94% when fully powered up and ready to fly and wondered about that. Something I noticed when looking at the flight data for the 3 battery cells on both flights is that cell #1 has lower voltage than the other two and near the end of the flight, cell #1 drops rapidly down to nearly 2v when the other two are still around 3.3v or 3.5v. I don't know enough to know whether this is normal. Btw...wasn't aware of ability to watch voltage during flight. Will begin doing so.

 

[tcope]

I keep the batteries on the charging hub when not in use, so they should always have a full charge when I start (is that bad?).

Yes. You should store lipo batteries around 30% - 50%. They will auto discharge if left off the charger so that is how they should be stored.

Keeping then at full charge all of the time will shorten their life.

 

[mavRic32]

There's a lengthy YT video about DJI Lipo battery care. The short version is:

1. Don't charge your batteries until the day you plan to fly
2. They're intelligent batteries, they auto-discharge after a few days to protect against being stored at full capacity
3. Ensure the firmware in each battery is up-to-date
4. Don't use a battery that shows any signs of bulging

 

[Picklesaw]

Calibrate the batteries. Drain it all the way down to 0%, then charge it more than 100% and voila! This fixed a problem for me.

 

[Remote Pilots Australia]

I keep the batteries on the charging hub when not in use, so they should always have a full charge when I start (is that bad?).

Yes, that's certainly not optimal for maximum battery life. The best storage level if you are not going to fly in the next 48 hours for any LiPo is 40-60%. Try not to fly them down below 25% every time also. Once in a blue moon it's not a problem ... even desirable a couple of times a year to run them flat but the last 10% should be done at home just hovering in the back yard not out and about flying.

When you are going to pack your kit up for more than a couple of days put the batteries in the charger dock and pull them off when you have two LEDs solid and the third flashing and store it away.

If you are going to rely on the self discharge feature then set it for a discharge time of 2 or 3 days not the maximum 10 .... I think DJI Go 4 gives you that option for the Mavic Air .... I have so many DJI birds now I get confused at which ones allow you to set this in the firmware and which don't and I fly the Air least. I'm too lazy to unpack the Mavic Air and check. If not disregard the last bit.

Regards
Ari