One key aspect that makes your mobile phone working is the batteries and if the batteries are not under the right quality then you cannot use the mobile phone efficiently. These become the common reason for the people to visit the Smartphone repair shop. There are certain reasons where your battery may need to be changed. Here are certain signs that your mobiles phones shoes to indicate that it is the time to change the battery.
When your phone shuts down unexpectedly

There are certain cases where your mobile phone gets shut down suddenly. Your battery may drain down easily and takes more time to get charged. When you need to re-calibrate your phone do the following.

Use the phone until it shows off as the result of low battery.
Connect your phone to the reliable charger and let it get charged and do not disturb till becoming 100%.
After reaching 100% perform a soft reset by holding your sleep and home buttons.
If this is not possible it is the only option to change the screen.

If your phone becomes sluggish

In the case of the iPhone you may be the victim of throttling. Tap the settings app to choose the battery option and select the battery health. This is one way to get rid of these kinds of iPhone repair.
When your phone work only if it is plugged in

When your battery is completely drained your phone will not be able to boot up when you plug them. However, if the phone is still able to be charged and when it can be connected to the power source and can function properly it means that the battery or the battery connector is the culprit of failure.
When your phone gets a heater soon

Generally, your phone battery will get heated when it is under function as the result of discharging the power. The lithium-ion battery present in your smart phone will is designed in order to internalize the heat; they are shielded from other parts of the phone. Even after that, if there is any leakage and when the heat leaks to the other parts of the mobile, it is the time to consider the battery replacement.
When the battery over grew your phone

You can find certain mobile phones are bulged or swelled. It denotes that the battery life is going low and it cannot use the power appropriately. At these instances, it is better to look for the mobile phone replacement. To avoid these issues it is better to avoid leaving the phone plugged in even after it reaches 100% or when you use them when they are plugged in etc.