I put this AA cell, which measured 1.3 volts – ‘dead’ – on one of my germanium Joule Thiefs more than a week ago. It was glowing very brightly for a few days. For the last few days, it has been weakly glowing, and the Kirkland AA cell is still hanging in there, even though its voltage is only 0.19 volts. This JT is milking the last few millivolts out of the cell, even though it’s far below the cutoff point for a silicon JT.
The weather has been hot, and the cells, especially AA cells, have been leaking electrolyte and corroding contacts. I had one JT with a battery holder go dead. I checked and found that the juice had wicked up the strands of wire in the leads, and the copper wires were corroded green and crumbling when it was moved. Yuck. The juice also eats away the chrome plating on the little magnets I used to hold the leads to the cells.
Update Oct. 5th evening – The LED is still glowing. This battery isn’t dying easily! It finally went out the next day.