I've read that NiMH and Lithium chemistries will only supply around half of their rated capacity when used at low temperatures (say around 0 degrees C).
Many sources also mention an increase in internal resistance and it is inferred that the two characteristics are related.
Now what if I'm working on a very low current application relative to the C rating of the battery? Say 0.01C. Do I still have to assume I will only get roughly half the mAh out of the battery? (My reasoning is that at low C discharge rates the internal resistance of the battery is less significant.)
Best Answer
The reasoning about the internal resistance is correct. To illustrate it, I found this plot for different discharge rates at low temperatures.
Energizer L91 Lithium Battery Capacity and Temperature Curve. Source.
There is another discussion about temperature and discharge rate here.