Lithium battery capacities (18650).

[Ian Field]

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?!

Thanks for any help.

 

[jeanyves]

On 2014-12-21 19:28:09 +0100, Ian Field said:

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?!

Thanks for any help.

hi,

chinese manufacturers are prown to mark everything they want on battery
capacity
between 1 and 2 times the real capacity.
it seems to be a constant from clone batteries
2 Ah for a 18650 battery is a good value to trust.
then there are devices that measure it, it's always a good tool if you
save batteries from trash.

--

Jean-Yves.

 

[Ian Field]

"jeanyves" <jeanyves@nowhere.com> wrote in message
news:54973504$0$2070$426a74cc@news.free.fr...

On 2014-12-21 19:28:09 +0100, Ian Field said:

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?!

Thanks for any help.



hi,

chinese manufacturers are prown to mark everything they want on battery
capacity
between 1 and 2 times the real capacity.
it seems to be a constant from clone batteries
2 Ah for a 18650 battery is a good value to trust.
then there are devices that measure it, it's always a good tool if you
save batteries from trash.

A capacity tester is probably a long term round-tuit.

The up and running application is an E-cigarette, the cells claiming to be
5.2Ah last a whole day and well into the next (if I forget to change over in
the morning).

There's a 2P3S pack claiming to be 4.2Ah that I'm wondering whether to leave
the parallel pairs intact.

Another round-tuit job is the discount store 5W LED handlamp that keeps self
discharging if I don't leave it permanently on the charger - the information
leaflet claims a 2.2Ah capacity cell.