7 signs your smartphone battery is dead

The battery is the heart of your smartphone. Without it, impossible to make a call, check social media or browse the Internet. Yet like any electronic component, it wears out over time. Here are the 7 signs that should alert you and push you to consider a replacement.

1. Your phone shuts down with 20% battery remaining

This is probably the most common sign. You look at your screen, it still shows 20 or even 30% charge, and poof: black screen. Your smartphone just shut down without warning.

This phenomenon is explained by the ageing of lithium-ion cells. Over time, the battery gauge becomes inaccurate because the actual capacity no longer matches what the software estimates. The displayed percentage is no longer reliable, and your phone shuts down abruptly due to insufficient energy.

If this happens to you regularly, it's a clear signal that the battery has lost a significant portion of its original capacity.

2. The phone overheats abnormally

A warm smartphone during a gaming session or GPS navigation is normal. However, a phone that gets very hot at rest, during charging or light use is an alarm signal.

A degraded battery has higher internal resistance, which generates more heat. This overheating further accelerates wear and can even become dangerous in extreme cases. If your phone is burning hot without apparent reason, have your battery checked quickly.

3. Charging has become very slow

Your smartphone used to fully charge in an hour, and now it takes three? Before blaming your charger, think about the battery itself.

A worn battery accepts current less efficiently. Built-in protection circuits may also reduce charging speed to prevent overheating. Try a different cable and adapter first. If the problem persists, the battery is very likely the cause.

4. The battery is swelling

This is the most visible and most urgent sign. If your back cover is lifting, the screen has a bump or the phone no longer sits flat on a table, your battery is probably swollen.

Swelling is caused by gas production inside the lithium-ion cell, the result of advanced chemical degradation. This is a potentially dangerous situation: a swollen battery can leak, catch fire or even explode. Stop using your phone immediately and take it to a professional repairer like Safe.

5. Random shutdowns

Does your phone turn off and on by itself, sometimes several times a day? These unexpected restarts are often linked to a battery that can no longer supply stable current to the processor.