Adding a protection-board to a non-protected cell ?

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DBSAR
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Adding a protection-board to a non-protected cell ?

Have any one tried removing a protection board from a dead, weak, or cheap LiIon cell, and transplanted it to a good non-protected cell ?
I have 2 really crappy red Crapfire cells that has a ridiculous high internal resistance, ( drops from 4.12 volts to 3.7 volts in a couple weeks) and they tested at a lethargic 560mah and 610mah each, but the protection circuits actually work. (cuts off the voltage at around 2.5 volts when discharging in a light that don;t have low-voltage protection.)
I was going to toss the cells to the recycle bin at the local HomeDepot, but wondered if the protection bases and side-strips could be salvaged and transplanted on laptop pulls, then re-wrapped.

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Jaidmaster
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I have never done it, but assuming you can solder to the unprotected cell, I don’t see why this wouldn’t work…

pilotdog68
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I’ve done it with the protection circuits fasttech sells. The hardest part was getting the solder connections clean and compact enough to still fit in a light.

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cbrake10
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pilotdog68 wrote:
I’ve done it with the protection circuits fasttech sells. The hardest part was getting the solder connections clean and compact enough to still fit in a light.

I wonder if solder paste might help with that? No experience, just spit-balling.

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Halo...
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You can also get seiko protection pcbs on aliexpress.

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I am looking for the button top of 18650’s, as a spare part. Any ideas?

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DBSAR
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zeremefico wrote:
I am looking for the button top of 18650’s, as a spare part. Any ideas?
some use small neodymium magnets, i have used just blobs of solder on most of mine.

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hank
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Remember the legitimate manufacturers will warn you never, ever try to solder to a Li-ion cell, because that heat can damage the thin membrane that separates the reactant chemicals (just as denting it, or dropping it, can do). Once that sort of damage happens you can get crystals slowly growing and eventual “Rapid Unplanned Disassembly”

The right way: have tabs spot-welded on; then you can solder to the tabs.