Hank, will you be taking this up with your supplier?
I have three of these on order (along with three protected Sanyo UR16650ZTs), and while I have lower draw lights, so it's not like I can't use these cells at all, I had been hoping to use them with higher ampage lights as well.
I don't blame yourself, as you can only go by what your supplier is telling you - after all, you can't pull apart every battery to check that it has been made to the desired specification - but it would be nice to get this resolved for future batches, if nothing else.
Benckie got 2940mAh down to 3V at 0.5A from the Intl-O protected NCR18650A. But it seems higher amps discharges are blocked by the obvious reasons.
old4570 got 2700mah from the Callie Kustoms at the same termination voltage and same discharging current, 3V and 0.5A. Also, old4570 got 2919mAh when discharged at 0.5A down to 2.5V
This might be related to how much they are charged. I did this test once:
Notice how small a change you need in the voltage to get a 5% change in capacity, also notice the drop in voltage when the battery is resting. You need a good voltmeter to be sure about the termination voltage and be strict with the resting time!
My test of Callies 3100 batteries gives 2885 mAh down to 3 volt and 2953 mAh down to 2.8 volt with 0.5 A discharge current.
Different battery batches (whether it is 2 years ago or 1 year ago) also makes a small diff i guess. These cells are most probably what some would call "surpluses". It depends on the age of such surpluses or batches.
I thought it did well once it leveled out, I asked my daughter to stay away from the battery while it was discharging, she asked me are we going to pop it dad lolls it did get bloody hot but did well.
Charged the batteries yesterday let the batteries rest over night then today discharged. (remember all my test since post number 85 have been with the protection PCB,s removed)
Cell Adischarged from 4.15 volt to 2.5 volt at 0.5 amps
In your first test with the PCB and 0.5A discharge, the cell was charged to 4.2V.
This one is starting from 4.15V, so theoretically the 3100mAh should have been achieved if the cell was charged to 4.2V
But for those charging to 4.15V is a good reference point.
Looks like we have some good cells with POS PCB's! The protected are useless for most of us unless running them in parallel or in a low draw/high capacity uses.
If you can get these cells with a kallie's pcb you will own the market!
To be honest with these cell after being rested from a full charger the voltage is around 4.18, the rested voltage of this cell was 4.159 after being rested, it might of droped 0.021 volt or so for sitting on the charger to long, before i removed it.
It would be a good test for people say using xtar chargers like the one i test a little while back they seam to cut out around 4.15 volt, better then over charging and the cells would last bit longer, but from 4.18 or 4.20 they would hit 3100 mAh no problem.
Im doing a 0.2 amp discharge from 4.163 volt to 2.5 volt for you now ill post the results tomorrow after work, the starting voltage of the discharge was 4.163 volt with a 0.2 amp load, i know its not 4.18 or 4.2 volt but that was the rested voltage after i charged it yesterday for this test, i thought it best not to try and top it up the rest it again.
I hope you still find the test useful.
What alarmed me was the such low mah testing with the pcb,s.
redilast and aw sell the same cell,s with good pcb,s but the price is higher.