When is a good time to replace an Iphonen battery? An easy-to-understand explanation!

Updated on 2023-07-01
Most batteries last at least two to three years and often longer, but how do you know when it is time to replace your iPhone battery? Here are some tips to help you know when to replace your iPhone battery.

The life of the iPhone battery is limited. It will gradually degrade over time as it is used. Most batteries can be used for at least two to three years and often longer, but how do you know when it is time to replace your iPhone battery?

Here are some tips to help you know when to replace your iPhone battery.

How iPhone Batteries Work

The iPhone runs on a rechargeable lithium-ion battery. It can charge faster and pack more power into a lighter battery than ever before. Older iPhones are more prone to battery problems than newer models with advanced features that compensate for battery degradation. However, all batteries degrade over time.

iPhone Battery Issues

If your phone shuts down unexpectedly or cannot make it through the day on a single charge, you likely have a battery problem. Other signs include slower running apps or lower-than-usual speaker volume.

How to Check iPhone Battery Health

To check the health of your battery, make sure your iPhone is charging, then go to the Settings app > Battery and tap Battery Status. Here you will see information about maximum capacity, peak performance capabilities, important battery messages, and when to replace your iPhone battery.

iphone battery "maximum capacity "

Here it becomes clear if the battery needs to be replaced. This percentage is a measurement of the phone's battery capacity compared to when it was new. Initially at 100% (or below), capacity decreases as the battery ages, meaning less time between charges; according to Apple, if the number displayed below the maximum capacity is 80% or higher, the battery is healthy.

Peak Performance Performance.

Peak Performance Performance is an indication of the iPhone's self-diagnostic system and shows whether the battery in your iPhone is performing to Apple's standard.

If there are no problems, "Your battery is currently meeting the standard Peak Performance. If there is a problem, it will say, "This iPhone experienced a sudden shutdown because the battery could no longer supply the required peak power. Performance management has been applied to prevent this from happening again. is now displayed.

How do I know when to replace my iPhone battery?

So what is the standard for replacing the iPhone battery?

When it reaches less than 80%.

Most smartphones, not just iPhones, use lithium-ion batteries as their power source. Lithium-ion batteries are destined to degrade over time due to chemical aging and cycles of full charges.

To prevent sudden shutdowns, it is advisable to replace the battery when it falls below 80% of its maximum capacity.

500 full battery charge cycles (1.5-3 years)

When you hear "when the capacity drops below 80%," it may be difficult to come up with the cost of battery replacement. So is there a standard number of years before battery replacement?

Apple's official page states, "The iPhone battery is designed to maintain up to 80% of its original capacity after 500 full charge cycles. A charge cycle refers to the number of times the battery is charged to a total of 100%.

For example, an iPhone battery consumes 75% of its capacity on day 1, is charged to 100% that night, uses only 25% of its capacity on day 2, is charged to 100% again that night, uses only 25% of its capacity on day 3, and is charged to 100% again that night.

Instead of counting the number of times the battery has been charged to 100% so far as the number of cycles, the "total number of times it has been charged to 100%" is counted as a full charge cycle. In other words, in this case, since 100% was consumed in two days, one cycle is two days.

If 100% is used every day, it would take about one and a half years to reach "500 cycles. If half of the battery is left at bedtime (before recharging), it will take about 3 years to reach 500 cycles, and the maximum capacity of the battery may be less than 80%.

Symptoms of Deterioration

Symptoms of battery problems
  • (1) Heat is generated
  • (2) The remaining capacity display is wrong
  • (3) The application crashes frequently.
  • (4) The screen becomes dark.
  • (5) The speaker volume becomes low.

If you have any of the above symptoms, you should experience considerable inconvenience when using your iPhone.

How to replace the iPhone battery

Replacing the battery is easy, cost-effective, and a great way to extend the life of your phone; DIY battery replacement kits are available, but you need to know exactly what you are doing, so it is best to contact an iPhone repair expert.


If you have AppleCare+ or your phone is under warranty, Apple will replace your battery for free. Otherwise, the cost will range from 5,940 yen to 77,480 yen depending on the iPhone model.

How to replace the battery at "(docomo, au, Softbank) carrier".

  • Repair fee: 5,940 yen to 77,480 yen
  • Repair time: Same day to 1 week
  • Data: Data will be erased at the time of repair.

How to prolong the life of your iPhone battery

We have introduced when to replace your iPhone battery, but whether you replace it or not, it is certainly a good idea to use your iPhone battery in a way that makes it last longer.

Below are some tips on how to make your iPhone battery last longer.

Update iOS to the latest version

Updates to the iPhone's operating system often include content related to power savings.

Frequent updates may help reduce performance degradation even as the battery degrades.

Use at a constant ambient temperature.

The optimal temperature at which the iPhone operates is set at "16°C to 22°C".

With respect to temperature, the iPhone is designed to operate between 0°C and 35°C. Using the iPhone outdoors for extended periods of time in summer or winter is not good for the battery.

In particular, leaving the iPhone in high temperatures, such as in a car in the middle of summer, will accelerate battery deterioration, and such use should be avoided at all costs.