When a battery loses its stored electrical energy over time, even if it’s not being used, is known as self-discharge. There are several factors responsible for this like chemical reactions, leakage, and temperature variations. This happens because of chemical reactions inside the cell, which are comparable to a small external force.
Essentially, it pertains to the phenomenon of self-sustaining electrochemical reactions that influence the rate at which batteries (accumulators) discharge. The speed of this discharge determines how much of the stored charge or capacity can still be used after storage.
Sometimes, the self-discharge rate can slow down over time because of things like lithium anodes forming a passivation film.
What Does the Rate of Self-Discharge Depend On?
The determinants of self-discharge rate can be attributed to various factors, namely atmosphere temperature, battery type, and battery technology. It is imperative not to underestimate the potential heat accumulation within the glove compartment.
Notably, self-discharge experiences a significant increase when subjected to temperatures surpassing +55 °C (131 °F). Storing batteries in storage rooms can expose them to extreme temperatures.
Batteries installed inside vehicles, especially in the engine compartment and in places with high temperatures, might face similar situations. The battery can maintain its charge capacity over time and give a longer lifespan by regulating self-discharge if stored at lower temperatures.
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