Mavic Pro just dropped out of the sky... what could cause that?

Product Support Forum
1

We got a Mavic Pro (the first one, I know it’s old) from eBay five days ago. It looked fine and the batteries only had 20-26 charges. We flew it twice with no problems, but today while hovering about 200 feet up and 20 feet in front of us, the motor made a noise then went silent and it just fell. I checked the flight logs and there’s nothing showing why it lost power. Battery was properly seated at 39% with normal voltage and cell readings. The props were all there except one broke when it hit the ground.

Has anyone else had this happen where the drone just drops with no warning or errors in the logs? I want to understand what might cause this.

2

At that age, I’d suspect failing battery cells. The number of charges doesn’t really matter for old batteries. The silence suggests a sudden loss of electrical power. If a prop failed midair, you’d hear it first. Sometimes the logs won’t show anything if the power just cuts instantly. Also, Mavic batteries can swell and push up, causing a disconnect.

3

@Nori
Yeah, that’s a known problem with the Mavic 1 and 2, Air 2, and 2S because of how the batteries sit on top.

4

Marlo said:
@Nori
Yeah, that’s a known problem with the Mavic 1 and 2, Air 2, and 2S because of how the batteries sit on top.

Exactly. Both my Mavic 1 and 2 had this issue — the 2 was worse. After a few minutes of flight, swollen batteries push against the lock and disconnect. This happens to a lot of people. All my Mavic 2 batteries swelled after about 30 cycles.

5

@Nori
I haven’t used regular DJI batteries but with old batteries wouldn’t you see battery sag? Or do Mavics not draw enough amps to notice sag?

6

Jules said:
@Nori
I haven’t used regular DJI batteries but with old batteries wouldn’t you see battery sag? Or do Mavics not draw enough amps to notice sag?

I’ve never seen sag, only swelling. Some batteries swell even when cold and unused, others only swell when warm and active. I’ve had several Mavic 1 and 2 batteries do both.

7

@Nori
The battery popped out when it hit the ground but didn’t look swollen then. I measured it later and it’s about the same size. It fits so tightly I guess a minor swell might not be obvious.

8

Payton said:
@Nori
The battery popped out when it hit the ground but didn’t look swollen then. I measured it later and it’s about the same size. It fits so tightly I guess a minor swell might not be obvious.

Swelling often goes down after cooling off a few minutes when not in use.

9

Old battery = failure, pretty much guaranteed.

10

If the battery was bulging underneath, it might have disconnected from the contacts.

11

Lin said:
If the battery was bulging underneath, it might have disconnected from the contacts.

I didn’t notice anything weird with the battery at the time or now. If it swelled I’d expect it wouldn’t go back to normal.

12

@Payton
Yeah, swollen batteries usually stay swollen.

13

Lin said:
@Payton
Yeah, swollen batteries usually stay swollen.

My Mavic 1 batteries would go back to normal once cooled, unlike my Mavic 2 batteries which stayed swollen.

14

DJI just wants you to buy a new one.