Do Lithium-Ion Batteries Degrade If Not Used? Understanding Longevity and Care
Lithium-ion batteries are ubiquitous in our daily lives, powering everything from smartphones and laptops to electric vehicles and home appliances. Understanding their behavior, particularly their degradation when not in use, is crucial for ensuring optimal performance and longevity. In this article, we will explore what happens to lithium-ion batteries when they sit idle, how to properly maintain them, and the best practices for extending their lifespan.
What Happens When Lithium-Ion Batteries Sit Idle?
Lithium-ion batteries, like all batteries, undergo physical and chemical changes over time, even when not in use. When a lithium-ion battery is fully charged, it can lose capacity due to a phenomenon known as self-discharge. This occurs as small amounts of energy naturally dissipate from the battery’s electrodes. Self-discharge rates can be influenced by temperature and the battery’s charge state upon storage.
Another key factor to consider is calendar aging, which is the aging process of batteries over time, regardless of usage. This means that even if you don’t frequently use your battery, it is still vulnerable to degradation due to chemical reactions within the battery cells. 
Storage Conditions Matter
The way you store lithium-ion batteries greatly affects their longevity. Here are some important guidelines to follow:
Optimal Temperature
Lithium-ion batteries should be stored in a cool, dry place. Extreme temperatures — particularly heat — can accelerate the degradation process. Generally, a temperature range of 20°C to 25°C (68°F to 77°F) is ideal for battery storage. 
Charge Level
It is best to store lithium-ion batteries at a partial charge level rather than allowing them to fully discharge or fully charge. A recommended state of charge for storage is around 40% to 60%. This helps minimize stress on the battery and can significantly enhance its lifespan.
Humidity Control
High humidity can lead to corrosion of the battery terminals and compromise overall performance. Storing batteries in a humidity-controlled environment can reduce the likelihood of moisture-related issues.
How to Maintain Lithium-Ion Batteries
Regular maintenance is key to ensuring the longevity of lithium-ion batteries. Here are some practical tips:
Periodic Recharging
If you plan not to use your lithium-ion battery for an extended period, consider checking and recharging it every few months to keep it within the optimal charge range. This prevents it from going into deep discharge, which can lead to irreversible capacity loss.
Avoid Complete Discharge
Try to avoid allowing your lithium-ion batteries to discharge completely. Deep discharges can cause stress to the battery cells, leading to degradation and reducing overall performance.
Keep Connections Clean
Maintaining clean terminals enhances connectivity and performance. Use a soft, dry cloth to wipe away any dust or corrosion that may build up over time.
Signs of Degradation
After a period of inactivity, it’s important to assess your lithium-ion battery’s condition before using it again. Here are some signs of potential degradation:
Recycling and Disposal
If your lithium-ion batteries show signs of degradation or you no longer need them, proper disposal is crucial. Many communities offer battery recycling programs that ensure safe handling of potentially hazardous materials. Always check local regulations regarding battery disposal to avoid environmental contamination.
Conclusion
While lithium-ion batteries are efficient and widely used, their longevity requires proper care, especially when they are not in active use. By understanding how storage conditions, charge levels, and periodic maintenance can impact battery life, you can maximize the efficiency and lifespan of your lithium-ion batteries. Remember, taking simple steps today can ensure that your devices remain powered for years to come.