Li-ion battery discharge question(s)

[Hagis2k]

Was some time ago since i studied electronics lol

But i have one 18650 cell and lets say if i run a constant current discharge at 100mA/h between 4.2V down to 3.0V and if it lasts 5hrs and 7min wouldn't that cell have the capacity of roughly 511mAh?
5 * 100 = 500 / 100mAh/60=1.66 7min * 1,66 11.6mAh if im not mistaking then it shall be around 511mAh ?

I think im on the right track but i just ask again to confirm

[cyr]

"mA/h" is a nonsense unit, and I don't quite follow your calculations.

But yes 100mA for 5 hours is 500mAh, and that seems to be the approximate capacity of your battery.

[Hagis2k]

Yes then at least i remembered something i assume, my calculations are 5hrs x 100mA = 500mAh then i divided 100mAh in 60min and get 1.66mAh per minute then 7min x 1.66 which gives me 11.62mAh for the 7min then 500+11.62 so i assume my battery delivers around 511mAh and not the claimed capacity

[Neverther]

100mA/h seems wierd unit (as stated above, Ive also seen W/h written, but that's the internet...) current change of 100mA in an hour.
With 100mA constant current you are draining 100mAh in one hour.
So just convert the dischargetime to hours decimal and multiply with the constant current used to drain.

5 7/60 h * 100 mA = 511.6666... ~ 512mAh    at  100mA load.

That's rather poor for 18650 so I assume you got either old laptopcell or old laptopcell rebranded as new chinese cell.
Not even two watthours at nominal 3.7V figure so even alkaline AA has more energy than that.

[Hagis2k]

Yes it is a chinese cell lol with fantasy ratings on it seems like the quality of the two shitty firepeak differs one is around 511-512mAh and the other is closer to 1000mAh so nothing near 3200mAh lol only ones i know is panasonic 3100mAh and 3400mA and yes i have ripped a few laptop batteries apart too

[amyk]

That's horrible even by Chinese 18650 standards... I'm guessing it's either a really worn-out recycled cell (most of the recycled ones are still 1500mAh+) or not a real 18650.