Decoding the Self-Discharge Mystery: Why Batteries Lose Charge Over Time

We've all experienced it - the frustration of picking up a device, only to find its battery has drained despite not being used. This phenomenon, known as self-discharge, is a common and natural occurrence in batteries. But why does it happen, and what factors contribute to this mysterious loss of charge? In this blog, we'll delve into the world of self-discharge and uncover the reasons behind this intriguing battery behavior.

Chemical Reactions at Play

Batteries are essentially chemical devices that convert stored chemical energy into electrical energy to power our devices. Self-discharge occurs as a result of ongoing, albeit slow, chemical reactions within the battery, even when it's not connected to a circuit. These reactions are primarily influenced by the materials and components used in the battery's construction.

Electrochemical Process

In most batteries, there are two electrodes - an anode and a cathode - separated by an electrolyte. Over time, small internal currents flow between these electrodes, leading to the gradual loss of energy as the chemical reactions progress. This self-discharge process is typically more noticeable in batteries with higher energy densities, like lithium-ion batteries, which are commonly used in smartphones and other portable electronic devices.

Temperature Dependency

Temperature plays a crucial role in self-discharge rates. Higher temperatures tend to accelerate chemical reactions within the battery, leading to faster self-discharge. On the other hand, lower temperatures can slow down the process. This is why you may notice that batteries stored in extreme temperatures lose charge more quickly than those stored in moderate conditions.

Battery Type Matters

Different types of batteries exhibit varying self-discharge rates. For example, nickel-cadmium (NiCd) batteries are notorious for their high self-discharge, losing up to 20% of their charge in the first 24 hours after being fully charged. In contrast, lithium-ion (Li-ion) batteries have significantly lower self-discharge rates, losing only around 5% of their charge per month.

Storage Conditions

Proper storage conditions can significantly impact self-discharge rates. Storing batteries in a cool and dry place can help slow down the chemical reactions, preserving their charge for longer periods. Conversely, exposing batteries to heat and humidity can accelerate self-discharge, resulting in reduced shelf life.

Battery Age

As batteries age, their internal chemical processes can become less efficient, leading to increased self-discharge rates. This is why older batteries tend to lose their charge more quickly than newer ones.


Self-discharge is a natural and unavoidable phenomenon in batteries, driven by ongoing chemical reactions within the cells. While it may seem inconvenient, understanding the factors that contribute to self-discharge can help us better manage and optimize battery usage. Choosing the right type of battery, storing them properly, and being mindful of temperature conditions are all essential steps in maximizing battery life and minimizing the impact of self-discharge. EVE ER14250 battery has the low self-discahrge battery rate, which it could deliver less than 1% in an appropriate temperature. Please come and visit our EVE official websites to check out more!