Re: >> AAA/AA NiMH Capacity CPF Member Tested - Please Participate - Now with Summary
My last 4 AA Eneloop cells completed the Break-In sequence. I copied the results for the other 8 cells from post #54.....
Break-In sequence (capacity set at 2000mAH):
Capacity calculated by charger at end of discharge cycle.
Cycle duration is length of time during last discharge, at the end of which the capacity is calculated.
Start V of cell.....Capacity (mAH).....Cycle duration (mins.)
#1 = 1.405...............2126.................350
#2 = 1.403...............2096.................350
#3 = 1.403...............2073.................341
#4 = 1.404...............2106.................348
#5 = 1.356...............2028.................339
#6 = 1.356...............2005.................331
#7 = 1.357...............2046.................339
#8 = 1.358...............2058.................338
#9 = 1.430...............2089.................343
#10 = 1.429..............2081.................344
#11 = 1.430..............2081.................340
#12 = 1.431..............2071.................340
Conclusions:
1. All 12 cells are very close to each other in capacity, demonstrating superior manufacturing and quality control.
2. All 12 cells had similar times during the discharge cycle, demonstrating similar capacities.
3. Eneloop cells are one of the few cells on the market where the actual capacity exceeds the advertised capacity by the manufacturer.
4. There is a limit to how much anode, cathode and electrolyte material can be incorporated in a AA cell case, without an increase in self-discharge due to a reduction in separator material between the anode and cathode plates. As these materials increase in volume, the separator material decreases in volume. This leads to leakage of electrons between the anode and cathode plates, which leads to an increase in self-discharge.
5. The benefits of using a 2700mAH cell compared to a 2000mAH Eneloop can be drastically reduced by the losses of capacity due to leakage, and the resulting increase in self-discharge.
6. The use of Eneloop cells is recommended in devices where very low current draws exists, such as wall clocks and remote controls. This is because the self-discharge rate is ridiculously low. When using a non-Eneloop cell in such devices, the reason a cell will have to be replaced is not from loss of service due to depletion from normal discharge, but rather loss of service due to depletion from self-discharge.
Jeff
