I've just noticed something interesting.
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.
2100 gets in the 3000,s with 1 amp discharge to 2.6 volt on the NCR18650A
So im not sure if that is 2.6v or 2.8 volt it must be 2.6v for those numbers on the 3100 test ?
HJK gets 2125 mAh out of a redilast 2600 mAh at 5 amp to 2.8 volt i get 2426 mAh down to 2.75 volt.
So you might be onto some thing HJK
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.
and room temp of the test, i quess there is 1000 things that could affect the results slightly.
Panisonic suggest the maxium discharge on these batteries is 2C, 6.2 amps, so i thought ill give it a go and include some graphs.
6.2 amp discharge test from 4.16 to 2.5 volt.
Data table (at the end of cycle)
Volts VS mAh
Volts VS Wh
Battery tempture at the end of test
55.6 degrees C
The 'knee' at 3.3v shows a highly stressed cell on 2c discharge Benckie!
M.
That knee might also be due to the testing equipment.
I have not done any test at 6 ampere, but all my test up to 5 ampere does show smooth curves.
Unlikely IMHO, I've seen all this before with lithium chemistry at high or maximum with some manufacturers rated c discharge claims.
M.
Ok, here is a discharge test at 7 ampere I just did:
Another heavily stressed battery shown by initial voltage sag/recovery.
Best to run lithium at 60% maximum rated 'c' discharge to avoid damage and get good life.
Exactly, and then it recovers a bit when it heats up. But there are no bumps midway in the curve.
That is true, they are the best cell out there. Interesting data.
M.
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 A discharged from 4.15 volt to 2.5 volt at 0.5 amps
Data table
Volts Vs mAh
Volts Vs Wh
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.
Since the Pcb's suck. I think hank should refund/ credit the extra $2 people spent on the batteries. I would like a refund/ credit of $6.
This is a very good thread. We're lucky we have multiple here people doing extensive tests and can compare and cross check their results.
I think that’s fair.