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Old October 23rd 17, 04:06 PM posted to rec.bicycles.tech
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Default Lithium Ion vs NiMh battery

On 10/22/2017 8:13 PM, Jeff Liebermann wrote:
On Sun, 22 Oct 2017 21:07:22 +0100, "Ian Field"
wrote:

All my 18650s were rescued from discarded laptop packs - if I get any duds,
there's no point complaining to anyone.


I have a small collection of such batteries. The problem is that the
spot welded + terminal is flat and is missing the "button top" used in
most removable 18650 cells. I had to buy a few magnetic "button tops"
which work well enough, but are easily lost or misplaced:
https://www.ebay.com/itm/282578704173
My testing, using a West Mountain Radio CBA-II discharge tester,
showed that the cells market 2200 ma-hr delivered 2000 ma-hr at 1.5A.
Good enough.

The 3W Tesco headlamp uses one, but my biggest application is my e
cigarette. That's been in service well over 5yrs and I've only had to swap
out a couple of battery sets.


Between the eCigarettes, eBikes, LED lighting enthusiasts, power
tools, and radio geeks, it's a wonder that one can find 18650 cells.

The one that came with the Tesco unit is only 1800mAh - I get a lot more
running time from salvaged cells.


I recently bought a few of the lowest priced 18650 on eBay. Garbage
in, lumens out. These were suppose to be 5800 and 5000 ma-hr but
delivered 1000 and 880 ma-hr:
http://802.11junk.com/jeffl/battery-tests/18650.jpg
After about 10 charge/discharge cycles, the 5000 ma-hr cell is showing
signs impending failure.


Oh please, did you really expect 5800 mAH from an 18650? There is no
such thing!

The cheapest way to buy flat top 18650 cells is to buy one of those USB
battery packs. Fry's has a 16,800 mAH model comprised of six 2800mAH
18650 cells for $17. That's $2.83 per cell.

For button-top cells, the source that Barry Beams provided is probably
the best option. I.e. for button-top
https://liionwholesale.com/collections/batteries/products/protected-panasonic-ncr18650b-3400mah-li-ion-18650-button-top-battery?variant=1925834564.
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