5 Signs Your iPhone Battery Needs Replacing

Your iPhone battery is designed to retain up to 80% of its original capacity after 500 complete charge cycles. But batteries are consumable components, and they all degrade over time. The question is: how do you know when yours has reached the end of its useful life?

Here are five clear signs that it is time to bring your iPhone in for a battery replacement.

1. Your Battery Drains Much Faster Than It Used To

If you used to get through a full day on a single charge and now you are reaching for the charger by lunchtime, that is a strong indicator of battery degradation. While background apps and settings can affect battery life, a sudden or gradual decline in how long your phone lasts between charges is the most common sign that the battery is wearing out.

You can check your battery health by going to Settings > Battery > Battery Health & Charging. If the Maximum Capacity is below 80%, Apple considers the battery consumed and recommends replacement.

2. Your iPhone Shuts Down Unexpectedly

A degraded battery cannot deliver consistent power to the processor, especially during demanding tasks like taking photos, opening apps, or using GPS navigation. When the battery cannot keep up, the phone shuts down to protect itself, even if the battery indicator shows 20% or 30% remaining.

If your iPhone has shut down unexpectedly, you may also see a message in Settings > Battery > Battery Health saying "This iPhone has experienced an unexpected shutdown."

3. Your iPhone Runs Hot

Phones generate some heat during charging or intensive use, and that is normal. But if your iPhone regularly gets uncomfortably warm during light use like browsing the web or checking email, the battery may be failing. A degraded battery has higher internal resistance, which generates excess heat during both charging and discharging.

Persistent overheating can also damage other internal components, so it is worth addressing sooner rather than later.

4. Your iPhone Takes Much Longer to Charge

A healthy iPhone battery charges from 0 to 100% in roughly two to three hours with a standard charger. If yours is taking significantly longer, the battery cells may have degraded to the point where they cannot absorb charge efficiently.

Before blaming the battery, try a different cable and charger first. If the slow charging persists with known-good accessories, the battery is the likely culprit.

5. Your Battery Percentage Jumps Around

If your battery drops from 50% to 20% in minutes, or jumps from 15% back up to 30% after a brief rest, the battery can no longer accurately report its charge level. This happens because the voltage curve of a degraded battery becomes unpredictable, and the software cannot estimate the remaining capacity correctly.

What to Do About It

If you are experiencing any of these symptoms, the fix is straightforward. An iPhone battery replacement takes 15 to 30 minutes and your phone will feel like new again. At iTech Repairs, we use high-quality replacement batteries and back every repair with a 90-day warranty.

We replace batteries for all iPhone models from iPhone 6 through iPhone 16. Walk-ins are welcome during business hours, and no appointment is needed.