I'm trying to get the capacity of18650cells I harvested from laptop batteries via fully charging and then fully discharging them, but the discharger stops and theresultingmAh's are much lower than the cell's rating and I even notice the resulting/resting voltages are around or above nominal. Here's a test showing what's happening...:
Any ideas why the capacities are coming back so low or why thecells don't appear to fully discharge?
P.S. - I know the cells are good because I charged them in November 2017 (actually might of been 2016)and when I took them out today to top them offfor their capacitytest they all read 4.1 V or higher beforehand.
Code:
Samsung ICR18650-28A
Rated specs:
2800 mAh (capacity)
1400/2800 mA (standard/max charge current)
560/5600 mA (standard/max discharge current)
3.75/4.30/2.75 V (nominal/charge max/discharge cutoff voltage)
Discharge settings:
500 mA (discharge current - 100 mA to 12000 mA are the options)
3.1 V (discharge cutoff voltage - 3.0 to 3.75 V are the options)
Test results:
1414 mAh (capacity)
3.06 V vs 3.71 V (discharger's reported voltage when it stopped vs voltage reading I got from multi-meter)
206 minutes (runtime)
Equipment:
XTAR VC4 (basic USB powered 4 slot multi-charger) to charge cells
HTRC H150AC/DC DUO (150W hobby charger) to discharge cells
Any ideas why the capacities are coming back so low or why thecells don't appear to fully discharge?
P.S. - I know the cells are good because I charged them in November 2017 (actually might of been 2016)and when I took them out today to top them offfor their capacitytest they all read 4.1 V or higher beforehand.