Relevant excerpts from the 2009 specifications of Samsung (Google search: filetype: pdf ICR18659-26F):
- The cells do not have a protection circuit (PCM).
- The minimum capacity is 2550 mAh (CC: 520 mA, 2.75 V cut-off).
- The applied charging method is constant current / constant voltage (CC / CV).
- The maximum charge voltage is 4.2 ± 0.05 V.
- Cells should not be discharged below 2.5 V, the benchmark for optimum cycle stability is 2.75 V.
- The maximum charging current of 2600 mA (1C).
- The maximum discharge current is 5200 mA (2C).
- The standard charging time is 3 hours, CC = 1300 mA (> 95% rel capacity corr 2400 mAh..).
- The Quick-charging time is 2.5h, CC = 2600 mA (90% rel capacity corr 2300 mAh..).
- The capacity to 299 cycles is 1785mAh (with standard charge / discharge cycles).
It can be assumed that with a fast charging, as those in the Amazon product description (1.2H), only a relative. Can be achieved capacity of <80% (acc. <2040 mAh).
Own measurements to verify the specifications:
- Shop: CC / CV: 1300 mA / 4.2 V (3h or 1 / 20C).
- Unloading: CC: 1000 mA (3V cut-off).
-> Capacity of 2410 mAh (corresponding to approximately 95% relative capacity.).
- Shop: CC / CV: 1300 mA / 4.2 V (3h or 1 / 20C).
- Unloading: CC: 500 mA (3V cut-off).
-> Capacity of 2500 mAh (corresponding to approximately 98% relative capacity.).
- Shop: CC / CV: 2600 mA / 4.2 V (1.8h or 1 / 20C)
- Unloading: CC: 1000 mA (3V cut-off).
-> Capacity of 2115 mAh (corresponding to approximately 83% relative capacity.).
It should be noted that the values determined by my values are only samples. However, the values correspond to the specifications in terms of the achievable capacity at the charge / discharge cycles applied. To cycle stability, I can not say anything.
Conclusion:
The nominal capacity should not pay too much attention generally. Who will discharge its cells with currents> 520 mA (0.2C) can not get the maximum capacity. For example, the max. Discharge current of 5200 mA (2C) as specified by only 80% of the relative capacity available (corresponding to 2040 mAh.). Who his cells also do not want to invite for 7 hours at 520 mA is obtained never 100% of relative capacity. Also, do not neglect the temperature dependence, in a wintry use eg falls, the relative discharge capacity of 80% at 0 ° C to 50% at -10 ° C from. (CC: 520mA, 2.75V cut-off). In this respect, most of these external conditions will play a crucial role in the performance of Li-Ion cells in practice anyway.
To get even 70% of relative capacity to 299 cycles (corr. 1785 mAh), as specified by CC / CV chargers are recommended with a charging current up to 1300 mA, whereby the discharge current in the application should not exceed 1500 mA.