I just wanted to warn the community for these batteries: "UltraFire CN 18650 9800mAh 3.7V" (Yellow with black imprints).
I was SO surprised that a manufacturer was so extremely dumb to put this extremely high capacity on his batteries that I just HAD to check how much there was in it in reality. The results were quite shocking.
I first charged them fully, checked voltage hot off the charger: 4.18V so this was good.
Then I discharged them with a current of just 450mA - no problem, isn't it?
Cut-off voltage was set to 3.0V as we all know that further discharge only damages the cells and doesn't bring much more capacity.
The outcome was 669mAh for cell #1 and 738mAh for cell #2.
After the first one, I was quite sure: something went wrong, as a small, short interruption in the discharging process cuts off the discharging immediately. After the second cell I knew: these are just VERY BAD CELLS. Nothing went wrong in the first discharge! I measured them after discharging and indeed: they were down to a bit more than 3V so really discharged....
My advice: don't buy them
I was SO surprised that a manufacturer was so extremely dumb to put this extremely high capacity on his batteries that I just HAD to check how much there was in it in reality. The results were quite shocking.
I first charged them fully, checked voltage hot off the charger: 4.18V so this was good.
Then I discharged them with a current of just 450mA - no problem, isn't it?
Cut-off voltage was set to 3.0V as we all know that further discharge only damages the cells and doesn't bring much more capacity.
The outcome was 669mAh for cell #1 and 738mAh for cell #2.
After the first one, I was quite sure: something went wrong, as a small, short interruption in the discharging process cuts off the discharging immediately. After the second cell I knew: these are just VERY BAD CELLS. Nothing went wrong in the first discharge! I measured them after discharging and indeed: they were down to a bit more than 3V so really discharged....
My advice: don't buy them