Data Mining: CR123 Cells

[Battery Guy]

Greetings Everyone

I mined some of the excellent data on CR123 cells collected by SilverFox and others, posted in the this thread.

Here is a plot of the data showing the relationship between discharge current and discharge energy.

I think this is a fantastic set of data, because it really shows the trade-off between energy and power for batteries.

Cheers,
Battery Guy

 

[Kestrel]

Very interesting. Another trend seems to be that cells that appear to be optimized for high w-h at low discharge currents tend to have lower than average w-h at high discharge currents compared to competing brands and vice versa.

Different behavior than "Cell X is above average compared to competing brands for both low & high discharge currents", which is not what appears to be happening at all.
:goodjob:

 

[Battery Guy]

Very interesting. Another trend seems to be that cells that appear to be optimized for high w-h at low discharge currents tend to have lower than average w-h at high discharge currents compared to competing brands.

That is, in essence, the trade-off between power and energy for any given battery chemistry.

Since all of these cells have the same chemistry (lithium negative electrode, MnO2 positive electrode), the only way to tweak performance is cell construction. To get more total energy at lower discharge rates, the manufacturer uses thicker electrodes to maximize the amount of active material (lithium and MnO2) in the cell. To get better performance at higher discharge rates, the manufacturers decrease the thickness of the electrodes to increase the electrode surface area and decrease the diffusion distance for lithium ions. Of course, when they decrease the thickness of the electrodes, the amount of active material in the cell decreases.

That is why I love this set of data so much. Rarely do you see enough test data from the same cell chemistry for so many different cells. You can clearly see the "cross-over point" where all of the cells have very similar performance at 1.4 A discharge. Also, you can see that the best performer at low rates (Sanyo) is close to the worst performer at high rates. Alternatively, the best performer at high rates (TitaniumNew) is second to worst performer at low rate.

Like I said, this is a beautiful set of data. Thanks SilverFox!

Cheers,
Battery Guy

 

[MichaelW]

Does the Tenergy contain a PTC?


The old, blue, Tenergy CR123s will literally run for a couple of months in the Inova X5 [white] vampire, then for a few more months in the X5 red.