Your smartphone uses a lithium-ion battery. It offers far improved experience than its predecessors from previous generations. Your smartphone includes advanced battery management software that allows you to experience cutting-edge features including fast charging, more available battery capacity, longer lifespan, all contributing to enhancing your battery experience.

Lithium-ion batteries have limited lifespans. Lithium-ion batteries need to be replaced after a certain duration of use. This aging process depends on many factors that may accelerate or reduce this degree of aging. Charging your smartphone in extreme temperatures (for example, directly in the sun) accelerates the chemical aging of the battery. Aging also depends on the total number of charge-discharge cycles.

Smartphone users notice battery aging as a gradual decrease in the amount of maximum charge capacity that the battery can hold. With aging, users experience a declining amount of battery use time. Battery performance is a simple measure that compares the maximum amount of charge that the battery can hold relative to when it was new.

Your battery management software includes state-of-the-art Adaptive Charging algorithms from Qnovo that operate in the background to monitor the battery’s performance and early signs of aging.  By studying the state of battery health and anticipating future aging, it dynamically adjusts the rate and degree of charging to make your battery experience seamless. A well-maintained battery should age slowly to give you more available charge capacity over time.

The Battery Monitor application collects unique diagnostic data from the Adaptive Charging algorithms and displays select information to the user. You can find the app and launch it on your Docomo smartphone. The app displays three measures: (i) battery charge level, also known as state of charge, (ii) battery performance, and (iii) the total number of charge-discharge cycles.

Battery charge level

The Battery Monitor displays the battery’s charge level indicating the amount of charge in the battery. A fully charged battery is at 100%. A battery that is at empty displays zero.

Battery performance 

Lithium-ion batteries are designed to hold a maximum amount of charge called maximum charge capacity. This is the same as the amount of charge that your battery can store when your smartphone is new. It is normally equal to the rated capacity of the battery in your smartphone, for example, 4,000 mAh. As the battery ages, the maximum amount of charge gradually declines. The amount of capacity that the battery can hold relative to when it was new is a measure of your battery performance. The Battery Monitor app displays it as a percentage relative to the maximum capacity of a new battery.

Your battery’s performance is considered normal when the maximum charge capacity is between 80% and 100%. When maximum charge capacity declines below 80%, the battery is at the end of its useful life and must be replaced. A battery operating at below 80% maximum charge capacity does not necessarily mean that there is a safety hazard. However, a user will experience degraded performance.

Battery charge cycle

The third indicator displays the cumulative number of charge-discharge cycles, also known as cycle count. You complete one charge cycle when you have used (discharged) an amount that equals 100% of your battery’s capacity. For instance, you might use 80% of your battery’s capacity one day, then recharge it fully overnight. If you use 20% the next day, you will have discharged a total of 100%, and the two days will add up to one cycle. Battery lifespan is the number of charge-discharge cycles until the battery’s maximum charge capacity reaches 80%. The battery in your smartphone is designed to last 800 cycles under normal operating conditions.

As an owner of a smartphone, there are general tips that will help you maintain the health of your battery and maximizing its lifespan.

Extreme ambient temperatures accelerate the aging of your battery. Avoid charging your smartphone in a hot environment (above 35° C) or in cold ambient temperatures (below 5° C). If you must charge your smartphone in your vehicle on a sunny day, look for a cooler location within your car instead of placing your smartphone on the dashboard.

If you must store your smartphone for long durations, it is important to observe a few precautions. First, charge or discharge your smartphone’s battery to around 50%. Second, ensure that your smartphone is powered off. Check every few weeks that the battery’s charge level remains near 50%. Store your smartphone at a temperature below 30° C. Do not store your smartphone in a refrigerator. Once you take your smartphone out of storage, remember to charge it as you would do under normal use.

Readers who wish to learn more about the lithium-ion battery and tips to maintain its health may visit our technical blog.

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