How to Know When Your iPhone Battery Needs Replacement

If your iPhone seems to be dying faster than it used to, you're not imagining it. iPhone batteries degrade over time — Apple says they're designed to retain up to 80% of their original capacity at 500 complete charge cycles. For most people who charge their phone once a day, that's about 18 months before battery health starts noticeably declining.

The good news: iPhone battery replacement in Citrus Heights is fast, affordable, and available same-day at MNM Computers. But first, let's make sure a degraded battery is actually the issue. Here are the five clearest signs it's time for a replacement.

🕔 Sign #1: Your iPhone Dies Before Reaching 0%

This happens most often during demanding tasks like gaming, GPS navigation, or video calls — activities that draw high power. If your phone shuts down during these but works fine in low-power states, the battery is almost certainly the culprit.

🕔 Sign #2: Battery Health Below 80%

Apple built a battery health monitor directly into iOS. To check yours:

1. Open Settings
2. Tap Battery
3. Tap Battery Health & Charging

If your Maximum Capacity reads below 80%, Apple itself recommends replacing the battery. Below 80%, you're essentially running your iPhone at a significant performance deficit — and it will only get worse over time.

🕔 Sign #3: iPhone Running Noticeably Slower

Apple's "performance management" feature (introduced after the 2017 battery controversy) intentionally throttles your iPhone's processor when the battery can no longer sustain peak power demands. This prevents unexpected shutdowns — but it also means a degraded battery makes your iPhone feel sluggish.

If apps take longer to open, animations stutter, or your phone feels like it slowed down after a major iOS update, check your battery health first before blaming the software. A new battery often makes an older iPhone feel significantly faster.

🕔 Sign #4: Battery Draining Unusually Fast

There's a difference between a phone that drains quickly due to heavy use and one that drains quickly doing nothing. If your iPhone loses 10–20% battery per hour while just sitting on your desk with minimal notifications, that's a problem.

To check if an app is the drain culprit:

• Go to Settings > Battery
• Review Battery Usage by App for the last 24 hours and 10 days
• If no single app is draining it, the battery itself is likely failing

🕔 Sign #5: Your iPhone Gets Hot While Charging

Some warmth during charging is normal. But if your iPhone gets noticeably hot — especially when using a charger it previously handled fine — the battery may be failing. Lithium-ion batteries generate more heat as they degrade because internal resistance increases. Excessive heat during charging can also accelerate battery deterioration in a feedback loop.

If your phone also shows slow charging times alongside the heat, it's a strong signal the battery needs attention.

How to Check Battery Health & When to Replace

The quick rule of thumb:

• 100%–80%: Battery is healthy — no action needed
• 79%–70%: Battery is degrading — consider replacement, especially if you notice any of the signs above
• Below 70%: Battery needs replacement — performance and reliability are significantly impacted

iPhone Battery Replacement in Citrus Heights — Same Day at MNM Computers

At MNM Computers, we replace iPhone batteries for all models — iPhone 6 through iPhone 15 Pro Max — using high-quality replacement cells. Most battery replacements are completed in under one hour, and we offer a free diagnostic to confirm the battery is the actual issue before we start.

We're located at 7613 Greenback Lane, Citrus Heights, Sacramento CA 95610, open Monday–Friday 10AM–6PM and Saturday 10AM–4PM. Walk-ins are always welcome.

Frequently Asked Questions