AAA Battery: Common Voltage and Chemistry for AAA Batteries
Alkaline - typically 1.5 volt, non-rechargeable
Lithium - 1.5 to 3.6 volt, non-rechargeable
NiCD - typically 1.2 volt, rechargeable battery
NiMH - typically 1.2 volt, rechargeable battery
Alkaline vs. Lithium
You may have noticed by now that the AAA batteries we carry are pretty similar in capacity. Whether these are disposable or rechargeable batteries, alkaline or lithium, most of the AAA batteries hold 800 mAh to 1250 mAh of reserve power. As an example, Energizer E92 (alkaline) vs. L92 (lithium) are identical in capacity, 1250 mAh. How then, does Energizer claim that L92 lasts 8 times longer than E92? The secret lies in the chemistry and the construction of the battery.
Alkaline batteries generate electricity from a reaction between zinc electrodes and manganese oxide paste, where the application would be optimal for low draining devices such as clocks, calculators and remote controllers due to the slow reaction time. When the power is drawn out quickly such as when taking a picture with flash, the battery cannot react fully throughout the battery and coats unused zinc electrodes with depleted reactants. As a consequence, the alkaline battery may lose its total capacity by half, or by as much as 2/3, lasting shorter than its intended cycle life.
Lithium batteries are constructed differently and have a much larger area for reaction, allowing as much power to be drawn out of the battery as possible. In other words, Energizer's claim of L92 AAA batteries lasting up to 8 times longer is not because of bigger capacity, but efficiency of drain.