On Wed, 15 Nov 2017 09:52:00 -0500, Bob Engelhardt
wrote:

On 11/15/2017 12:09 AM, Jeff Liebermann wrote:
...
If you're having problems charging cells which exhibit low terminal
voltage (under about 2.5v), try this:
https://www.youtube.com/watch?v=tbEfhPbqTDE

I came away with this clever tip: use small magnets to hold test leads
to the ends of cells.

Yep. However, I suspect that may have been an accidental discovery.
When one salvages 18650 cells from a laptop battery pack, the
resulting cells do not have a projecting button top on the positive
electrode. Getting such a cell to make a proper connection in a
battery holder or flashlight is problematic. So, someone determined
that a tiny magnet will stick to the positive terminal and provide a
suitable button top contact (and test lead connection):
https://www.ebay.com/itm/New-15pcs-Battery-Magnet-Spacer-Convert-Flat-to-Button-Top-All-Lithium-ion-/282548150944

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558