Hello everyone,
I just wanted to share a little test I've done. I had some old stock MNKE IMR 26650 that was never used laying around. Almost all of the cells had a terrible idle increase in internal resistance when stored inside in a climate controlled environment at the cells ship voltage of around 3.8v. Originally all cells were around 20 mili ohms @ 1Khz AC. Now most cells are 120-160 mili ohms, which is basically unusable for high current applications. I decided to see what happened after a few cycles so I put it on my iCharger and did 10 full charge/discharge cycles. The cell that measured 131 mili ohms is now reading 61. Which 61 is still not good but is a heck of a lot better than 131.
I just wanted to share this. I'm doing another 10 cycles to see if there is any more decrease in IR or if thats it. Any one else notice this problem with some cells? I've noticed it in these MNKE IMR cells and also some other Chinese IMR. Then I've also seen this problem in the Samsung 28A and 30A. Large increase in resistance and slight capacity loss just when the cell is stored for 2 years in a climate controlled environment at its ship voltage.
I also have 10 year old Sanyo 2400mAh cells that provide brand new IR and capacity.
I just wanted to share a little test I've done. I had some old stock MNKE IMR 26650 that was never used laying around. Almost all of the cells had a terrible idle increase in internal resistance when stored inside in a climate controlled environment at the cells ship voltage of around 3.8v. Originally all cells were around 20 mili ohms @ 1Khz AC. Now most cells are 120-160 mili ohms, which is basically unusable for high current applications. I decided to see what happened after a few cycles so I put it on my iCharger and did 10 full charge/discharge cycles. The cell that measured 131 mili ohms is now reading 61. Which 61 is still not good but is a heck of a lot better than 131.
I just wanted to share this. I'm doing another 10 cycles to see if there is any more decrease in IR or if thats it. Any one else notice this problem with some cells? I've noticed it in these MNKE IMR cells and also some other Chinese IMR. Then I've also seen this problem in the Samsung 28A and 30A. Large increase in resistance and slight capacity loss just when the cell is stored for 2 years in a climate controlled environment at its ship voltage.
I also have 10 year old Sanyo 2400mAh cells that provide brand new IR and capacity.
