lwknight
Enlightened
I have studied several graphs of cell discharge tests and there seems to be a linear correlation between remaining voltage and remaining usable charge of Li-ion 18650 cells.
My quandary is that I tested (not so scientifically,) a 3000mah ultrafire cell at 1.2 amp load that dropped from 4.2 volts to 3.7 volts in 20 minutes till the pcb kicked out. OK no surprise here for the over rated XXfire cell.
Next the strange thing. I tested a ultrafire 2400mah li-ion cell the same way. It took 25 minutes to draw down to 3.7 and then another 45 minutes to draw down to 3.6 and 20 minutes to draw down to 3.5 at which I terminated the test.
Are t he grey UF2400s a different chemistry that allowed it to draw down to 3.7 volts and then just keep giving and giving without dropping significantly?
I used a 600 lumen cheap P-60 in a 501b host and monitored the temperature and brightness to be pretty stable throughout the test. I did wrap the pill with a round and round of aluminum foil till it fit tightly.
My quandary is that I tested (not so scientifically,) a 3000mah ultrafire cell at 1.2 amp load that dropped from 4.2 volts to 3.7 volts in 20 minutes till the pcb kicked out. OK no surprise here for the over rated XXfire cell.
Next the strange thing. I tested a ultrafire 2400mah li-ion cell the same way. It took 25 minutes to draw down to 3.7 and then another 45 minutes to draw down to 3.6 and 20 minutes to draw down to 3.5 at which I terminated the test.
Are t he grey UF2400s a different chemistry that allowed it to draw down to 3.7 volts and then just keep giving and giving without dropping significantly?
I used a 600 lumen cheap P-60 in a 501b host and monitored the temperature and brightness to be pretty stable throughout the test. I did wrap the pill with a round and round of aluminum foil till it fit tightly.
