Effects of Moderate Power Consumption Loads on Alkaline Batteries

Alkaline batteries have higher energy density and exhibit good discharge characteristics in low-power applications, but their performance gradually degrades under medium-power loads. As the load current increases, the battery's internal resistance begins to significantly affect the battery's performance. Medium power consumption devices require the battery to provide stable current output. During this process, the alkaline battery needs to complete its internal electrochemical reaction at a faster speed, which will cause some side effects inside the battery, such as increased internal resistance and heat. Losses increase.
The internal resistance of alkaline batteries increases as the discharge current increases. When the load current increases to tens or hundreds of milliamps, the battery's output voltage will decrease significantly due to the voltage drop caused by the battery's internal resistance. This voltage drop prevents the device from getting the stable voltage it needs, especially in devices that require higher voltages, which can cause reduced device performance or earlier battery failure.
Energy efficiency and losses
Under moderate power consumption loads, the energy efficiency of alkaline batteries is typically lower than their nominal capacity. Due to the large load current, the battery's chemical reactions cannot fully utilize the active materials inside. As the current increases, the reaction between the zinc anode and the manganese dioxide cathode speeds up, but it also produces more by-products, such as a zinc passivation layer, which affects the overall chemical reaction efficiency of the battery.
What's more, as the current increases, so does the battery's internal heat loss. The electrolyte inside alkaline batteries is more likely to generate heat under moderate power consumption, especially during long periods of discharge. The generation of heat not only reduces the actual energy output, but also accelerates the aging process of the battery. Excessive heat can cause the electrolyte to evaporate or leak, shortening the battery's life.