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Harvesting Issue
#11
Personally - I wouldn't fool with it / risk it.   Almost new cells are very cheap these days - not as if they are $10 each Smile
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#12
Hello guys, Im new and i luckily can't add this from my experience yet. I always seemed to twist them with pliers. It sometimes damaged the wrap but from a few 100 harvested cells i've never had a leaking cell happen.
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#13
(09-23-2020, 01:38 PM)quadrofource Wrote: Hello guys, Im new and i can add this from my experience too. I always seemed to twist them with pliers. It sometimes damaged the wrap but from a few 100 harvested cells i've never had a leaking cell happen.
If you pull hard/sharp-enough it can happen.  The 'cans' of 18650 cells are not 'thick metal' as they seem and if you pull out a really strong spot weld (instead of clipping the nickle off) you can get a hole Smile
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#14
(09-23-2020, 04:08 PM)OffGridInTheCity Wrote:
(09-23-2020, 01:38 PM)quadrofource Wrote: Hello guys, Im new and i can add this from my experience too. I always seemed to twist them with pliers. It sometimes damaged the wrap but from a few 100 harvested cells i've never had a leaking cell happen.
If you pull hard/sharp-enough it can happen.  The 'cans' of 18650 cells are not 'thick metal' as they seem and if you pull out a really strong spot weld (instead of clipping the nickle off) you can get a hole Smile
im lucky it never happened to me yet Big Grin
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#15
(09-23-2020, 04:08 PM)OffGridInTheCity Wrote:
(09-23-2020, 01:38 PM)quadrofource Wrote: Hello guys, Im new and i can add this from my experience too. I always seemed to twist them with pliers. It sometimes damaged the wrap but from a few 100 harvested cells i've never had a leaking cell happen.
If you pull hard/sharp-enough it can happen.  The 'cans' of 18650 cells are not 'thick metal' as they seem and if you pull out a really strong spot weld (instead of clipping the nickle off) you can get a hole Smile

I just have to lay off the Wheaties then.
I have started to try twisting them off. It seems to be more of a problem with dewalt battery packs with thick metal tabs.. All the ones that have had holes are from those packs..
Wish there was an easier way to disassemble them with out causing lots of sparks. Gets me every time at least once.
Metal drops below the protective ring then zap sparks.. Makes me jump every time..  Smile
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#16
(09-24-2020, 06:10 AM)cyberblob Wrote:
(09-23-2020, 04:08 PM)OffGridInTheCity Wrote:
(09-23-2020, 01:38 PM)quadrofource Wrote: Hello guys, Im new and i can add this from my experience too. I always seemed to twist them with pliers. It sometimes damaged the wrap but from a few 100 harvested cells i've never had a leaking cell happen.
If you pull hard/sharp-enough it can happen.  The 'cans' of 18650 cells are not 'thick metal' as they seem and if you pull out a really strong spot weld (instead of clipping the nickle off) you can get a hole Smile
dropping bits of tabbing through the vents can cause a welded short you cannot remove.
if its a good cell with enough charge this can mean an "oh shit" event.
when i am cleaning cells i use magnetized flush cutters.
the crumbs stick to them and i can clear them off.
never had any short a cell.

I just have to lay off the Wheaties then.
I have started to try twisting them off. It seems to be more of a problem with dewalt battery packs with thick metal tabs.. All the ones that have had holes are from those packs..
Wish there was an easier way to disassemble them with out causing lots of sparks. Gets me every time at least once.
Metal drops below the protective ring then zap sparks.. Makes me jump every time..  Smile
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#17
(09-10-2020, 05:06 AM)cyberblob Wrote: Have a question for the more experienced battery harvesters.
I have been harvesting some old cells and found a few that have a hole from where the weld pulled the bottom case open.
Is this safe to charge and use?
This happened to me only once on an old Sanyo cell in my experience harvesting 100+ laptop batteries.
Easiest to remove:
1. Green Sony ones used copper strips, they are easiest and safest to remove without damaging the negative side of the cell. You can just pull it with bare hands, it just leaves 4 copper dots without spikes.
2. Some Panasonics have only 2 weld spots, remove it rocking back and forth without pulling and not applying much force.

Some Sanyos have tough full nickel strips, I prefer to leave them ON, cutting around the wled spots with side cutting pliers and bending the edges back to the cell bottom. Looks clean and 100% safe.
Are you harvesting power tool batteries? They have thick 0.2mm full nickel strips and bigger spot weld points, I recommend to not remove them on the negative sides, just cut it around.
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#18
To the questions regarding holes:

NO. If you already made a hole that means you have contaminated the inside.

Cells with damage should be binned. It is not worth the gamble. Keep it safe.
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#19
If you dont want your cells to be sad Sad just leave the nickel strips ON
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#20
(09-30-2020, 09:01 PM)slipkn67 Wrote: If you dont want your cells to be sad Sad just leave the nickel strips ON
Brilliant!  Keep the smiling ones and toss the rest Smile
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