Battery case cracked

[Max67]

Purchased a used battery on eBay. Came with a crack in the case. Have an inquiry out to the seller, but they seem to be a salvage reseller so I'm not hopeful they'll be any help. Trying to decide whether to return it or tape up the crack and give it a go.



I know DJI and conventional wisdom warns against using damaged batteries, but this damage seems to affect the exterior hardcase only. Any thoughts on how it might have happened (crash, crush, ... ?), how likely actual cell/wiring/connector damage might be, whether to consider further examination and/or testing and how to go about doing so?

Any information about internal construction, assembly, disassembly, etc. would also be appreciated.

Thanks.

Mike Maxfield

 

[DanMan32]

Damage could have occurred by crash or other means such as being accidentally stepped on. Battery is probably OK. There are two LiIon cells inside that are cylindrical metal cans. The rest of the outer case in your picture doesn't show any other damage so it should be OK. Cautiously test with a few charge cycles/low altitude/distance flights before using it regularly.

 

[Deleted member 113929]

Damage could have occurred by crash or other means such as being accidentally stepped on. Battery is probably OK. There are two LiIon cells inside that are cylindrical metal cans. The rest of the outer case in your picture doesn't show any other damage so it should be OK. Cautiously test with a few charge cycles/low altitude/distance flights before using it regularly.

Good advice.

 

[bumper]

If you can squeeze the crack back together with little effort (i.e. no pressure from the inside), you might try gluing it back together with super glue, used sparingly.

 

[lannes]

If you paid next to nothing for the battery, I'd try and use it as mentioned by other posters.
If you paid normal prices I'd return it

 

[Max67]

Thanks, all. I plan to cautiously test as advised and may attempt the CA glue repair if all checks out. I'll let you know how it works out.

Thanks again,

Mike

 

[OregonEd]

Thanks, all. I plan to cautiously test as advised and may attempt the CA glue repair if all checks out. I'll let you know how it works out.

Thanks again,

Mike

I have one that looks exactly the same. I use it almost daily with out any issues or attempt to repair. I was cautious with the first couple of cycles. Mine functions perfectly. “YMMV”

 

[Max67]

I have one that looks exactly the same. I use it almost daily with out any issues or attempt to repair. I was cautious with the first couple of cycles. Mine functions perfectly. “YMMV”

Thanks, that's reassuring. ? One cycle so far with no incidents. ?

 

[Max67]

Found a great series on teardown of the MM here - DJI Mavic Mini Teardown : What's inside?. It includes teardown of the RC and battery with high res pics showing lots of detail on internal components/construction. Highly recommended.

PS. Still wringing out my cracked case battery. So far, so good.

 

[Flycaster]

I would not use Ca adhesive. They have a tendancy to outgas as they cure. And can leave a white crust on surfaces.
There is a product called Devcon Plastic Welder. (6 bucks a card).Like a 2 part epoxy, this is designed for plastics. Just stuff a small amount into/down the crack, and compress/tape it together for a few hours and good to go.

 

[Max67]

I would not use Ca adhesive. They have a tendancy to outgas as they cure. And can leave a white crust on surfaces.
There is a product called Devcon Plastic Welder. (6 bucks a card).Like a 2 part epoxy, this is designed for plastics. Just stuff a small amount into/down the crack, and compress/tape it together for a few hours and good to go.
View attachment 101434

Great idea. Thanks.