Is this cell still usable?

[Svoloch88]

I have dropped this puppy when taking it out of my star charger and it resulted in the plastic housing cracking near the positive node of the 18650 3400mah plantronics cell. Is it still safe to use?

My assumption is yes as this is just the housing to keep the barebones from showing and to put the labeling on the cell.

However I am a cautious person and decided to ask from some of you modders and risk takers who have opened up protected cells to make make them unprotected and vice versa.

Thanks in advance.

 

[Gauss163]

[...] My assumption is yes as this is just the housing to keep the barebones from showing and to put the labeling on the cell [...]

The plastic wrapper plays a greater role than that. Namely, since the entire metal can of the cell is the negative terminal, the wrapper serves to reduce the size of the negative terminal - isolating it at the bottom of the cell - far away from the positive terminal on top. But now your wrapper is torn and the upper cell can edge (negative) is exposed very close to the positive button top. Now there is only about 1/8 inch separation between negative and positive parts, which greatly increases the chance of a short. For example, a key or coin that contacts the button top and the exposed top edge would cause a short, which might lead to venting (with flames). It is essential to rewrap the cell in order to prevent such.

 

[Svoloch88]

The plastic wrapper plays a greater role than that. Namely, since the entire can of the cell is the negative terminal, it serves to reduce the size of the negative terminal - isolating it at the bottom of the cell. In particular, the upper edge of the cell (now exposed) is also negaive, and is very close to the positive button cell. This greatly increases the chances for a short (e.g. keys, coins, etc could connect the button top to the top edge, yielding a short). It is essential to rewrap the cell in order to prevent such.

Thanks for the quick reply Gauss.

Hmmm I'd rather just sell it at a discount then. I do not have any of the materials to rewrap it, let alone do it right from the first try.

Does anyone want it at a discount? Say 12 bucks and I pay shipping?

 

[CanadianGuy]

I don't post here often, but I thought I'd toss in another possibility. Could you get shrink-wrap and gently heat it around the cell in place of the plastic wrap?

 

[Svoloch88]

I don't post here often, but I thought I'd toss in another possibility. Could you get shrink-wrap and gently heat it around the cell in place of the plastic wrap?

I could but I use these in some very high powered torches. They heat up immensely. To the point that they will ignite paper if placed on top of the reflector. So imagine the sticky mess the shrink wrap will leave when I need to recharge the cells.

 

[Gauss163]

Hmmm I'd rather just sell it at a discount then. I do not have any of the materials to rewrap it, let alone do it right from the first try.

It's not difficult to rewrap a cell, e.g. see HKJ's tutorial.

 

[Svoloch88]

It's not difficult to rewrap a cell, e.g. see HKJ's tutorial.

Thanks for that I'll have a look I guess at the investment costs into repairing it.

 

[Dale P.]

Shrink wrappers for 18650 cells are cheap and there are tons of venders selling them on E bay as well as other sources. I picked up 50 pre cut wrappers for less than $3.00 a while back and they are super easy to use. A hair dryer is all you need to shrink this tubing. NO need for a torch or heat gun!

Dale P.