How Long Can an Unused Smartphone Battery Last in Storage?

Maintaining a smartphone in storage can be challenging due to the potential for battery drain and damage. This article delves into the lifespan of an unused smartphone battery, offering insights and practical advice to help you preserve your device for as long as possible.

Understanding Battery Self-Discharge

LiPo (Lithium Polymer) battery experts recommend storing batteries at about a 75% charge level. This is a good starting point, as it minimizes the risk of the battery becoming too discharged or bloated. According to experts, LiPo batteries self-discharge at a rate of about 5% per month. This rate translates to approximately 15 months before the battery is fully discharged if left uncharged.

Proper Storage Practices

To ensure that your smartphone battery lasts as long as possible, it is crucial to follow proper storage practices:

Power Off the Phone: Before storing your phone, make sure to turn it off. This prevents any residual power from draining the battery. Optimal Charge Level: Charge your phone to about 80–90% before storing it. If the phone is brand new, it can maintain a reasonable charge for up to two years in storage. Temperature Control: Keep your phone in a cool place. Exposing it to temperatures above 35–40°C for extended periods can cause the battery to swell, potentially damaging your device or causing a fire hazard. Periodic Recharge: To maintain battery health, recharge your phone to 80% every 9–12 months. Overdischarge can significantly reduce battery lifespan.

Special Considerations for Newphones

When purchasing a new phone, it's often stored in the store for months. The battery is usually charged to about 50% to prevent damage and ensure it retains its charge. Upon purchase, it is recommended to avoid fully charging the battery before storing it for an extended period. This practice is crucial as fully charged batteries can deteriorate more quickly.

Battery Health and Storage Conditions

The battery's health plays a significant role in its storage life. Here are some key points to consider:

Excellent Condition: If the battery was charged to around 50% before shutdown and stored properly, it may hold a charge for several months, possibly 6–8 months or more, before dropping to 0. Poor Condition: If the battery was not in optimal condition or was undercharged before shutdown, it may discharge to 0 in just a few weeks. Replacement Batteries: Any replacement battery you purchase is likely more than 15 months old, meaning it's mostly discharged. If the battery is very dead, it could be damaged and pose a significant fire hazard when charged.

Final Recommendations for Safe Storage

To ensure the safety and longevity of your battery while storing your smartphone:

Charge to Optimal: Always charge your phone to 80–90% before storing it. Powert Off: Turn off the phone before storing. Cool Storage: Store the phone in a cool place to prevent thermal damage. Regular Checks: Charge your phone to 80% every 9–12 months to maintain battery health. Avoid Fully Charging: Do not fully charge a new phone before storing it unless you charge it to 50%.

By following these guidelines, you can help extend the lifespan of your smartphone's battery and ensure it remains in safe operating condition when you are ready to use it again.