I like those results mauch better :)
Benckie, would you do a discharge for the NCR18650A at 0.5A down to 2.5V please, now that they bare.
Yeah Benckie, you could do a 0.5A. Then i also do mine, and then i can see how accurate is my IMAX B6.
Sure i can do that they should hit 3100 mAh easy maybe a bit more, would you like a voltage VS mAh graphs as well ? i still would like to include the data tabes i normaly use also, i would really like to do 6.2 amp discharge.
It might be a couple of days off as im doing some discharges on some redilast,s 2600 blacks and playing with some graphs [quote=2100]
Yeah Benckie, you could do a 0.5A. Then i also do mine, and then i can see how accurate is my IMAX B6.
[/quote]
Thats a good idea.
Try lilo mode, i can use lilo mode to discharge below 3 volt but not to charge to 4.2v, im waiting on a firmware update for the icharger for this
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.
This must be said: thanks for all your hard work regarding these cells benckie, really appreciated.
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.