No problem. It may just be the nature of this charger/analyzer (Lii-500). It consistently indicates lower capacity figures on all cells I test with it by about 5-6%.
The chart they posted (see below) shows them measuring capacity using various current levels, starting with as low as 0.5A and going up to 8A. At 0.5A, their tested capacity is 812mAh. The main difference is their cutoff voltage is 2.5V. Mine is 2.8V, but there can’t be much capacity left there at that point.
Notice that the “begin volt” is 4.198V. This is almost impossible to achieve even with cells fresh out of the charger, I assume they must have set the termination beyond 4.2V in order to start the test at such high voltage. Probably around 4.25-4.3V.
With the MC3000 you get an option of “d reduce” which is the equivalent of a reversed CV phase for discharging, maybe with a termination current low enough along with the high starting voltage the 800mAh+ capacity can be achieved.
When people say down to 2.5/2.8V do they mean under load or not? No one seems to make the distinction but i’m pretty sure it makes a not insignificant difference depending on the rate.
U took the words from my fingers
Thanks for the test CRX!
Mine should be arriving next week, and I’m looking forward to use them Thanks to Vapcell :partying_face:
Cool :THUMBS-UP:
These tests give a better real life usage perspective on performance rather than just testing the cells in a discharge rig.
The results differ in every run due to temperature etc except the lower level regulated runs.
I must admit seeing it like this makes me start leaning towards regulated drivers more as opposed to just FET driven.
Different cell but here's the FW3A started on Max for comparison too.
Well, not really. I've conducted a practical DIY test to prove that. I once set a small test led attached direct drive to a couple old li-ion cells which, after a little bit more than a couple days of discharge (I could still see the die lit), I put my finger on the stuff and connected one of the cells which somehow wasn't making contact and wooosh! The led got again a lot brighter (and my eyes :-D were hurting). Since I was using flimsy wire and the cells were going to be recycled anyway I didn't cared if one cell was going to recharge the other and etc, they were initially at less than ≈40% anyway. So I decided to wait again, and after ≈3 additional days, with the led emitter very dimly lit, I disconnected the stuff. I could have let it go even lower if you will, but I think there is no point. This simulates a slightly below 2.5V discharge at ultra low discharge rate.
Wanna know the result? After some resting time (2 or 3 hours maybe, can't recall for sure right now) one of the cells measured 2.59V in my multimeter and the other scored just a tiny bit below 3V. As you may guess the 2.59V unit was the one which was discharged first.