Conceptual knowledge related to Alkaline battery

2021-03-09 08:59:41

Alkaline battery uses mercury-free zinc powder and new additives, so the capacity of alkaline battery is higher than that of carbon battery. The reason is that the manganese dioxide used as the anode has higher purity and density, and the volume of internal parts is smaller (for example, electrode), which also release space and helps increase capacity. In general, the capacity of alkaline battery is 3 to 5 times more than that of carbon batteries. However, the capacity of Alkaline battery will decrease with the increase of output current. For example, the same battery have a capacity of 3000mAh at low output current, but in the circumstance of a load of 1A current, the capacity will only be 700mAh, which is less than 1/4 of the original itself.


The electromotive force (e.m.f) of a single alkaline battery, that is, the voltage at no load is generally 1.5V, but the voltage varies between 1.5V and 1.65V with different manganese dioxide and zinc oxide. When the load is connected, the voltage will drop with the increase of the output current, and the voltage will drop to about 1.1V to 1.3V under normal load.

The output current of Alkaline battery is larger than that of carbon-zinc battery, but smaller than ordinary battery. Alkaline batteries with larger capacity can output larger currents because the electrode area increases and more substances can produce chemical reactions at the same time. Excessive current will heat up the battery during discharging. Generally, AA size batteries can output 700mA without heating up significantly. Larger models of C size and D size batteries can withstand greater heating without mutual heating.