Add Protection to Unprotected 18650 Batteries

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doslyn
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Add Protection to Unprotected 18650 Batteries

Is it possible to add protection circuitry to unprotected 18650 batteries? If so, where would a person buy the parts to do this?

Crux
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It looks like DX.com has some SKU: 26114 is for 14mm dia cells they may have others.

MRsDNF
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Two different ones here. It appears they are either 2 or 4 amp.

http://www.fasttech.com/products/1616/10003003/1225103

 

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doslyn
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Thanks. I know this is a stupid question, but how do you attach these to the batteries? Do you have to solder to the negative end?

Richwouldnt
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Battery Junction offers protection circuits too.

http://www.batteryjunction.com/pcb.html

Rich Wood
Reno, NV

Helios-
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Personally I would avoid any protection pcb which doesn’t use a seiko chip. Seiko is regarded as the best, all of the better batteries seem to use them. Protection chips sometimes fail, I suspect the failure rate is higher with those other random chips.
2pc 18650 4A-6A Seiko protection $5.98 ($2.75 / piece) free shipping.
20pcs 18650 4A-6A Seiko protection $25.66 ($1.10 / piece) free shippping
Wire strips
Kapton tape is used to isolate the wire.
Anatomy of a Protected LiIon Battery


Counterfeit 18650s, 2,<a href=“http://

leaftye
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doslyn wrote:
Thanks. I know this is a stupid question, but how do you attach these to the batteries? Do you have to solder to the negative end?

They're welded, but you may have to solder.  A battery tab welder costs about $150.  There's a guy on the other forum that plans to do a write up when he gets his.

The low mode should be lower.

comfychair
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Just adding more stuff to go wrong. Use quality unprotected cells, charge them properly, check them often. You should be doing those things anyway.