On Sun, 21 Dec 2014 18:25:32 -0000, "Ian Field"
wrote:

Having discovered that recycling bins in various shops are a good source of
lithium battery packs that can be put to various uses, I notice quite a
spread in claimed Ah capacities on the information labels.

The first aquisition was labelled "5.2Ah" - there weren't any parallel
combinations as it contained an uneven number of cells.

The next rescue was marked "4.2Ah", and contained 3 sets of parallel pairs -
so I assume the individual cell capacity is 2.1Ah.

The next was lowest yet at 2.0Ah.

This seems to be quite a spread for apparently identical cells, so I'm
wondering if I'm missing something?!

Yep. You're missing 2 things.
1. You posted your question in the wrong newsgroup.
2. All the battery capacities that you've found in the dumpster are
probably lies.

I tested an Ultrafire 18650 cell:
http://802.11junk.com/jeffl/LiPo/
For a 3000 ma-hr battery, I obtained a capacity of about 900 ma-hr at
1.3Amps:
http://802.11junk.com/jeffl/LiPo/Ultrafire%20LiPo%203000%20ma-hr%2018650%20test.jpg
The 1.3A is the current drain of the flashlight using the battery and
is somewhat higher than the normal test current.


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