What is the remaining battery life of a used smartphone? Let's check the maximum capacity as well.
One of the key concerns when purchasing a used smartphone is "battery life and degradation."
While used smartphones are more affordable than new ones, making them seem like a good deal, there's a possibility that the battery has deteriorated depending on the previous user's usage. If the battery level is low or its maximum capacity has significantly decreased, it could affect the device's usability and lifespan.
This article will delve into the basics of battery life in used smartphones, how much degradation to expect, and what happens when a battery reaches the end of its life.
We will also cover important points to check when choosing a used smartphone and methods for battery replacement, so please use this as a reference.
What is battery life in a used smartphone?
In used smartphones, "battery life" generally refers to the "remaining maximum capacity."
On an iPhone, you can check this value by going to "Settings" → "Battery" → "Battery Health."
A maximum capacity of 80% or more is generally considered to be still quite usable.
For Android, the method to check battery life may vary depending on the model and OS, but you can get a general idea of the condition using battery check apps.
Purchasing a used smartphone with significantly reduced battery life often leads to poor battery retention and sudden shutdowns.
Therefore, it is advisable to choose a model with a "battery maximum capacity of 80% or more" if possible.
Is battery degradation normal for used smartphones?
Compared to a new state, it is natural to assume that the battery of a used smartphone has already undergone a certain degree of degradation.
Smartphone batteries use lithium-ion cells, which gradually lose capacity with repeated charging and discharging.
The extent of degradation can vary significantly depending on the previous user's charging frequency and usage patterns.
For example, if the phone was consistently kept at full charge or frequently used in high temperatures, degradation might have progressed faster than usual.
On the other hand, a device that was managed with appropriate charging cycles and temperature control might still have a relatively healthy battery.
Reasons why a used smartphone's battery may not last long
If your used smartphone's battery isn't lasting as long as you'd expect, there could be several reasons. Here, we'll organize the typical factors.
High frequency of smartphone use
If the user plays games, watches videos, or uses social media for extended periods, battery consumption will naturally be high.
It's often due to usage style rather than being a used device that the battery doesn't last. It's a good idea to check if any apps are constantly running in the background.
Weak signal strength
In areas with poor signal reception, your smartphone constantly searches for a signal, which consumes extra battery power.
It's important to note that this isn't necessarily more severe for used devices, as the usage environment and signal conditions also play a role.
Low battery capacity of the purchased model
Older models may have inherently smaller battery capacities compared to current models.
Furthermore, with used phones, degradation adds to this, often leading to a perception of extremely poor battery life.
Device settings
If the screen brightness is always at maximum, or if Bluetooth and GPS are left on, the battery will drain unnecessarily.
If notifications and background updates are enabled for many apps, consumption will be even more severe, so it's worth checking.
Incorrect battery information at the time of purchase
If the information from the used electronics store is inaccurate, it's possible for the battery to be significantly degraded even if it's stated as "90% remaining."
It is necessary to check the actual battery condition before purchasing, or to choose a store that offers a warranty.
Smartphone screen is always bright
The display accounts for the majority of a smartphone's power consumption.
Even setting the brightness to auto-adjust, or manually setting it a little darker, can improve battery life, so give it a try.
Estimated lifespan of a used smartphone battery
Generally, smartphone batteries are said to start showing noticeable degradation after about 2 to 3 years. After this period, it's more common for the maximum capacity to fall below 80%, leading to symptoms such as the battery running out quickly within a day or slower charging speeds.
In the case of used smartphones, many devices have already been used for 1 to 2 years, so the effective remaining battery life is often around 1 year, or up to about 2 years with careful maintenance.
Understanding this, it's crucial to assess "how much longer it can be used" when purchasing a used device.
What happens when a battery reaches the end of its life?
As a battery approaches the end of its life, it doesn't just hold a charge less effectively; it also impacts the device's performance.
Here are two specific symptoms caused by battery degradation.
Reduced power delivery
When a battery deteriorates, during demanding tasks (such as gaming or video playback), the power supply may not keep up, which can lead to stuttering performance or sudden reboots.
Especially in cold environments, like winter, battery performance tends to temporarily decrease even further.
Smartphone system malfunctions
In the case of iPhones, when battery degradation becomes significant, the system attempts to stabilize operation by reducing performance, which can lead to a perceptible slowdown in operation.
In extreme cases, problems such as sudden shutdowns or charging not progressing no matter how long you wait may occur.
How to check the maximum battery capacity of a used smartphone
Ideally, you could check the maximum battery capacity before purchasing, and in physical stores, you might even be able to handle the actual device.
For online sales or auctions, you could ask the seller to provide a screenshot, among other methods.
Below is a brief summary of how to check for both iPhone and Android.
iPhone
- Open "Settings".
- Select "Battery".
- Tap "Battery Health" to see "Maximum Capacity". - 80% or more is relatively good, while around 70% indicates a high likelihood of significant degradation.
Note that the screen display may vary depending on the iOS version, so it's preferable to check with the latest iOS if possible.
Android
- Depending on the manufacturer and OS, you might be able to view details by going to "Settings" → "Device care" → "Battery".
- If not displayed by a standard function, it's common to install a battery check app to confirm.
- Compare "Designed capacity" and "Current actual capacity" in the app or settings screen to estimate the degree of degradation.
However, since Android has no unified specifications, the verification procedure may vary by model.
How to choose a used smartphone with a long battery life
If you want to get a used smartphone with the best possible battery condition, pay attention to the following points.
Check the information for models officially announced by the manufacturer
In recent years, manufacturers and specialized websites sometimes publish battery capacity and actual usable time. Referring to this information can help you target models with large battery capacities.
For example, iPhone Pro and Max series often feature larger batteries, and for Android, you should look for models with battery capacities of 4000mAh or more, both domestic and international.
Check the rank of the used smartphone you plan to purchase
Used smartphone retailers may rank devices (S, A, B, etc.) based on their external appearance and operating condition.
Some shops also factor in battery condition in addition to exterior scratches and years of use, so checking the details can help you find a device with less battery degradation.
Purchase from a used retailer that checks battery status
Some stores and online shops may state "guaranteed maximum battery capacity of ○% or more."
Purchasing from a shop that provides such information disclosure can reduce the risk of getting a lemon. Be sure to also check the warranty system to see if they offer refunds or exchanges if the condition is significantly different from what was stated.
Where to replace a used smartphone battery
Even if a used smartphone's battery is significantly degraded, if you like the device, it's possible to extend its lifespan by replacing the battery.
Here are three main places or methods for battery replacement.
Repair Shops
Local repair shops and specialized vendors can quickly replace iPhone and Android batteries.
While they may not always use genuine parts, they often offer affordable prices and same-day service. However, be aware that this may void your manufacturer's warranty.
Mobile carrier shops
If you purchased your device from a carrier, you might be able to request repairs or battery replacement at a carrier shop.
However, if it's outside the warranty period or a used purchase, it will likely be a paid service.
It might take time for parts to be ordered, so it's smoother to check by phone in advance.
Do it yourself
Self-repair batteries and kits are available, so if you are skilled with your hands and understand the procedure, you can replace it yourself.
However, the difficulty is high, and there is a risk of damaging other parts during disassembly.
Furthermore, waterproofing may be lost and the manufacturer's warranty may be invalidated, so it is not highly recommended for beginners.
When buying a used smartphone, consider the battery level carefully
The remaining battery life of a used smartphone is a crucial factor that significantly affects how comfortably you can use it.
While a maximum capacity of 80% or more is still practical, used devices that have already been in use for one to two years often show signs of degradation.
Therefore, the key is to check the battery condition of the device as thoroughly as possible before purchasing, and after purchase, to improve battery life by adjusting settings and usage habits.
Even if the battery is significantly degraded, there are replacement options, so maintaining a device you like for a longer period is also a viable approach.
To make smart choices when buying a smartphone, it's essential to thoroughly check detailed device information from reliable shops or websites.
PRODIG official online store for used smartphones and tablets offers a curated selection of used smartphones, emphasizing condition and operational checks.
Make sure to check the battery information thoroughly to get a used smartphone that balances cost-effectiveness and quality.
