I've never been able to find any data for these new low-self-discharge cells at low temperatures other than a bit of marketing liturature that says they work well. So I've run a few tests, each with 2 cells. The ambient temperatures varried a little during discharge, not more than 3 or so degrees and I'll indicate which direction.. Cells and C-9000 were left in the ambient conditions for 2 hours prior to discharge. Cells discharged at 400 mah.
Cells formed (and last charge) on Jan 9th for 1925 and 1933 mah capacity.
Discharged at 55 F (+3) for 1737 and 1755 mah capacity. (90%)
Cells formed (and last charge) on Jan 9th for 1967 and 1929 mah capacity.
Discharged at 39 F (-3) for 1750 and 1711 mah capacity. (89%)
Cell formed (and last charge) on Dec 31st for 1917 mah and Jan 2nd 1962 mah capacity.
Discharged at 27 F (-2) for 1715 and 1725 mah capacity. (89%)
I also ran some Enduros... Formed on Dec 31st for 2050 and 2050 mah capacity.
Discharged at 27 F (-2) for 1777 and 1758 mah capacity. (86%)
If your curious, all cells were formed with ambient temperatures of about 55-60 deg.
So far so good! Voltages appeared to hold up well and I haven't yet run into a real appreciable reduction in expected capacity. I just need to figure out how to go lower, I'm going to need to find some kind of freezer since winter here is warming up. Had I been more on the ball we had a few nights in the teens a few weeks ago. I believe this data already shows that both varieties are performing better than regular NiMH cells would.
Cells formed (and last charge) on Jan 9th for 1925 and 1933 mah capacity.
Discharged at 55 F (+3) for 1737 and 1755 mah capacity. (90%)
Cells formed (and last charge) on Jan 9th for 1967 and 1929 mah capacity.
Discharged at 39 F (-3) for 1750 and 1711 mah capacity. (89%)
Cell formed (and last charge) on Dec 31st for 1917 mah and Jan 2nd 1962 mah capacity.
Discharged at 27 F (-2) for 1715 and 1725 mah capacity. (89%)
I also ran some Enduros... Formed on Dec 31st for 2050 and 2050 mah capacity.
Discharged at 27 F (-2) for 1777 and 1758 mah capacity. (86%)
If your curious, all cells were formed with ambient temperatures of about 55-60 deg.
So far so good! Voltages appeared to hold up well and I haven't yet run into a real appreciable reduction in expected capacity. I just need to figure out how to go lower, I'm going to need to find some kind of freezer since winter here is warming up. Had I been more on the ball we had a few nights in the teens a few weeks ago. I believe this data already shows that both varieties are performing better than regular NiMH cells would.
