As usual, the truth is somewhere in the middle: https://iopscience.iop.org/article/10.1149/1945-7111/abad69
No, the truth is "not in the middle", the truth is the truth, you know, the actual physical reality. Truth does not follow social games, we don't "make deals" in order to be nice to each other. Giving correct information is my only priority, everything that works against it, I ignore or fight against.
Yes, it's very common mistake to mis-apply the Peukert formula due to small observable capacity difference caused by the combination of Low-Voltage Cutoff (which is always arbitrary, you have to use
something) and equivalent DC resistance of the cell. In any case, the effect on capacity is small, a few %. The question is only about whether the exponential Peukert law is a good model for li-ion, and the answer is no.
If you choose LVC poorly, or the application demands high currents and can't work down to lower voltages (which is of poor design, similar to crappy gadgets which refuse to work with alkaline cells at 1.2V, causing unused charge to remain), then yes, you can force-fit the observations into the Peukert law and
calculate a non-unity Peukert exponent. This does not make the Peukert law a suitable tool for analyzing li-ion cells, which is why it is never normally used. Fitting an exponential formula into a fairly linear system makes little sense.
Nothing prevents you from:
* Using low enough LVC, or
* Using dynamic LVC, or
* CC-CV discharging the cell
to fully utilize the charge in the li-ion cell. Done that way, calculated Peukert exponent will be very very close to 1.
Finally, li-ion cells are rated by the manufacturer typically at 0.5C or 0.2C discharge down to typically 2.5V or 2.8V. There is very very little extra to be gained, no matter how low current you are using. Maybe a few %, unless you take a risk of overdischarging the cell.
Yes, some of us actually have a scientist background, some of us have published papers in peer reviewed journals, or reviewed papers by others so know the process, and some of us have actually made some career on analyzing and testing li-ion cells. I'm really not the only one here who qualifies on all these. Those who have an ego issue and need to try to shine on something they have not the slightest clue about, maybe think about what damage it causes to the forum and the projects of others? The options for us really are stay quiet and let the wrong information shine, or correct the errors with the risk of the clueless egoists starting to fight back, derailing the thread. What would you choose if I spewed some BS about something
you know very well, and you think is important? Think about this for a while and forget about your pride, it's worthless, mine at least is and I love to be shown wrong. Thank you in advance.