It’s not safe. The contacts are corroded.
Caius said:
It’s not safe. The contacts are corroded.
Would WD-40 help clear the corrosion?
Caius said:
It’s not safe. The contacts are corroded.
Would WD-40 help clear the corrosion?
Only if you charge it at 50 amps right after! (Kidding, of course).
@Caius
Haha, okay, got it.
That blue stuff you see is oxidized copper. It’s unusable.
Oakley said:
That blue stuff you see is oxidized copper. It’s unusable.
Is it not safe to at least try WD-40? There are screws on the sides—could I safely open it?
I’d be surprised if any part of the drone is usable, let alone the battery.
Winter said:
I’d be surprised if any part of the drone is usable, let alone the battery.
Drone’s in for repairs as we speak 
Main board and gimbal survived, but the ESC board needed fixing.
Please don’t risk flying with that battery. Imagine the damage if it fails mid-flight. Replacement is much cheaper.
There is a fix, but given your questions, I don’t think you’re ready to attempt it safely.
Bryn said:
There is a fix, but given your questions, I don’t think you’re ready to attempt it safely.
Can you at least tell me? Give me a shot!
Best to take the battery to a recycling center. $150 isn’t worth the risk to your safety.
Nope, safely dispose of it. Better safe than sorry with batteries.
Saltwater is brutal on electronics—definitely time to let it go.
FYI, when DJI replaces a battery under warranty, they require you to submerge the old battery in saltwater on video. That tells you all you need to know!
You could try scrubbing it with isopropyl and a toothbrush, but only if you’re testing it far from people.
Try a contact cleaner on the corrosion—might help, but no guarantees.