Are these cells ok to use?

Andee

New member
Joined
Jan 14, 2018
Messages
2
Hi All,

I'm a newbie to 18650 harvesting. Have so far harvested around 80 cells.

Pictures are of a few of those.

The green panasonics all came from the same pack. 12 cells in all.
You can see in the group of 5, there is 'brown' under the wrap.
The photo of the single cell I pulled the wrap down to get a better look at it.
All of these 12 cells tested fine and are all good capacity.
My question to you is are they ok to use?
I am hoping it is not leakage and can be cleaned up and re-wrapped.

The blue cell came from a Optus modem with battery backup.
3 cells harvested. This one though appears to have same as the panasonics.
I didn't test this one but it does have good voltage.

Thanks for any advice.

Cheers

Andee



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NO! If there's rust, it's just temping something to go wrong. You don't know how much rust is under the top cap and at the CID. This could weaken or block the CID so it either blows early (moderate charging) or not blow at all if something goes wrong. I would not trust cells with rust on the caps.

If there isn't any rust on the cap end, but there could be some bubbling in the wrapper, then they might be ok. But I wouldn't trust them in a power pack application. Probably stand alone applications like a flashlight or something.
 
Honestly, did you really think that they might be ok and could be used? Obviously they aren't ok, they are rusty and shouldn't be used.
 
If they are rusty - they will continue to rust. Why compromise a whole pack for just a few cells.

I have had cells with just small specks of rust on them and cleaned them and re-wrapped them - and the rust just comes back.
 
Once the outer shell is compromised (the nickel plating), the steel plate underneath is exposed and will continue to rust.
 
Nope.. Nope..

The metal casing isn't that thick and the rust is a deal breaker.

If they are less than 3V I put in recycle bin.
If they somehow still hold a charge I discharge at ~200 mA (only if can be done safely) and put in the recycle bin.
 
Bin all cells damaged. Doesnt matter if its the CID, rust or just dented. I bin them all.
 
I had these used ebike cells in storage. I decided to use some of them this week, but I noticed corrosion on the positive ends of a few. The damage ranges from kind of mild to bad. They were kept in a locker outside, a bit close to the ground and I think they must have gotten wet.

There are guys on youtube re-using these suckers, .but not me. I had 30, and now I only have 12 left and I may as well bin those too,

They all tested well, good mah and low IR. Can't waste my time though,

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I had these used ebike cells in storage. I decided to use some of them this week, but I noticed corrosion on the positive ends of a few. The damage ranges from kind of mild to bad. They were kept in a locker outside, a bit close to the ground and I think they must have gotten wet.

There are guys on youtube re-using these suckers, .but not me. I had 30, and now I only have 12 left and I may as well bin those too,

They all tested well, good mah and low IR. Can't waste my time though,

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I do keep cells that don't pass my quality check (capacity, IR, self-discharge), I use them for tests, for e.g. I used them to do my spot welding tests and for a heavy load discharge test. But I bin cells with rust or with dents because they could fail anytime, maybe tomorrow or in 3 years time, and that could be a problem (worst case: fire).
 
For a small powerbank or flashlight I would use them if they test OK. For a powerwall- definitly no.
 
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