Why Does My iPhone Keep Turning Off?
If your iPhone shuts off on its own — sometimes with battery left, sometimes right after a restart — nine times out of ten it's the battery, not the phone. We see this every week at all four of our Massachusetts shops, and it's almost always fixable in under an hour. Here's what's actually happening and how to tell what your phone needs before you spend a dime.
First: check your battery health before you assume the worst
Lithium-ion batteries degrade with every charge cycle. After a couple years of daily use, the battery loses its ability to deliver quick bursts of power — the kind your iPhone needs when the camera fires up or a notification hits mid-scroll. When the battery can't supply that peak current, the phone's voltage drops faster than iOS expects, and it shuts down to protect itself, even if the screen showed 30–40% a second earlier. That's not a bug — it's iOS reacting to a battery that's wearing out.
Check it yourself in under a minute
- Open Settings
- Tap Battery
- Tap Battery Health & Charging
- Look at Maximum Capacity
Apple's own guidance is that a battery is designed to retain 80% of its original capacity at 500 complete charge cycles. Below 80%, random shutdowns get common — and if the screen also shows a “Peak Performance Capability” note, iOS has already detected the battery can't reliably deliver full power. If Maximum Capacity is still above 85% and you're still losing power randomly, keep reading — it might not be the battery.
If it's not the battery, here's what else it could be
Battery is the most common answer, but not the only one. Here's how to tell the difference.
Cold weather
Lithium-ion batteries lose voltage fast below freezing. If your iPhone only shuts off outside during a New England winter and comes right back on once it warms up in your pocket, that's temperature — not a failing battery — and it doesn't need a repair.
Verdict: normal, no repair needed
A software bug after an iOS update
Occasionally an iOS update itself causes shutdown loops on certain models. Check Settings > General > Software Update — if a newer version is available, install it before assuming it's hardware.
Verdict: check for a software update
Corrosion from liquid exposure
Even a small splash months ago can corrode the battery connector or logic board over time, causing intermittent shutdowns that look exactly like a battery problem but aren't fixed by a new battery alone. This needs a real diagnostic under a scope, not a guess.
Verdict: needs a hands-on diagnostic
A loose charging port or battery connector
If the phone shuts off when you move it a certain way, or only while charging, the battery connector inside may be loose or damaged rather than the battery cell itself.
Verdict: needs a hands-on diagnostic
A failing power button
Less common, but a stuck or shorting power button can force random restarts that feel like shutdowns. If your phone reboots instead of staying off, this is worth ruling out.
Verdict: quick to check, easy to confirm
The screen goes black, but the phone is still on
If the phone still rings, vibrates or connects to your car while the screen stays dark, it isn't shutting off at all. That's the display failing, usually the panel under the glass after a drop or pressure, and a new battery won't fix it. Our iPhone screen repair page explains the causes and lists screen prices by model.
Verdict: a screen problem, not a shutdown
Restarting every few minutes? That's a different problem
A one-off shutdown that happens once or twice a day is usually the battery. A phone that reboots on a short, repeating cycle — every 2 to 3 minutes, over and over — is a different symptom, and it's almost always hardware, not the battery wearing down.
Check the panic log before you guess
iOS keeps a record every time the phone crashes and restarts, and you can read it yourself:
- Open Settings
- Tap Privacy & Security
- Tap Analytics & Improvements
- Tap Analytics Data
- Look near the top for entries starting with panic-full — the most recent one matches your latest restart
You don't need to be able to read the whole log. Just confirm one exists and note the timestamp — that tells you the restart was a hardware-triggered crash, not the phone simply running out of power. Bring the phone in and we'll read the panic log during your free diagnostic to help narrow down the cause.
Proximity sensor fault
The proximity sensor near the earpiece is what turns your screen off during calls. When it fails or reports bad data, it can trigger repeat crash-and-restart cycles on some models. This shows up in diagnostics, not by looking at the phone.
Wireless charging flex cable
The wireless charging coil connects to the logic board through a flex cable. If that flex is damaged, pinched, or was disturbed during a previous repair, it can cause the kind of short, repeating restart loop that looks like a software problem but isn't.
Water or moisture damage
Corrosion on the logic board — even from a splash you don't remember — can create intermittent shorts that force the phone to keep restarting. This is one of the more common causes of a fast, repeating reboot loop, and it needs to be checked under a scope, not guessed at.
None of these are things you can diagnose by eye. If your iPhone is restarting every few minutes, don't keep resetting it — bring it in and we'll check the panic log, the proximity sensor, the wireless charging flex, and the board for moisture damage as part of the free diagnostic. Call (857) 302-2655.
What we actually check during a free diagnostic
When you bring an iPhone in for random shutdowns, we don't just swap the battery and hope. We pull the battery health percentage and cycle count, check the charging port and battery connector for corrosion or damage, and test the power button. If anything points to liquid damage or board-level corrosion, we tell you before we touch anything — that's a different repair than a battery swap, and we'll always give you the honest read on which one you actually need.
Diagnostic is free. You get a firm price before we start any work, so there's no surprise when you pick the phone up. Call (857) 302-2655 and we can usually tell you same-day whether it's the battery.
iPhone battery replacement pricing
Real prices, by model. These reflect our current parts costs and can shift if supplier pricing changes — call and we'll confirm the exact price for your model before you drive over.
| Model | Price |
|---|---|
| iPhone 16 / 16 Plus / 16 Pro / 16 Pro Max | $119–$129 |
| iPhone 15 / 15 Plus / 15 Pro / 15 Pro Max | $109–$119 |
| iPhone 14 / 14 Plus / 14 Pro / 14 Pro Max | $109 |
| iPhone 13 / 13 Mini / 13 Pro / 13 Pro Max | $99 |
| iPhone 12 / 12 Pro / 12 Pro Max | $99 |
| iPhone 12 Mini | $89 |
| iPhone 11 / 11 Pro / 11 Pro Max | $79 |
| iPhone X / XR / XS / XS Max | $79 |
| iPhone SE (2020 / 2022) | $79 |
| iPhone 8 / 8 Plus | $79 |
| iPhone 7 / 7 Plus | $59–$69 |
| iPhone 6 / 6s / 6 Plus / 6s Plus | $59 |
What's included: a free diagnostic before we quote anything, and a 90-day warranty on the finished repair. A 3% convenience fee applies to card payments, including Apple Pay; prices don't include MA sales tax. Most battery swaps run about 30–45 minutes once we have the part in hand — call (857) 302-2655 to confirm same-day stock for your specific model.
Visit us in Watertown, Newton, Burlington, or Wakefield
We run four repair counters across Eastern Massachusetts — Watertown, Newton, Burlington, and Wakefield — plus an on-site mobile van if you can't get to a store. Walk in with the phone, we'll run the diagnostic while you wait, and most battery jobs are done the same visit. Call (857) 302-2655, or reach the Newton store directly at (617) 992-4003, to check same-day availability at your closest shop.
Frequently asked questions
Why does my iPhone randomly shut off even when the battery isn't at 0%?
Is it my battery or something else?
How do I check my iPhone's battery health myself?
Will my iPhone stop shutting off if it's just cold outside?
How much does an iPhone battery replacement cost at Fix 'N Repair?
How long does an iPhone battery replacement take?
Will replacing the battery definitely fix the shutdowns?
What if my iPhone still shuts off after getting a new battery somewhere else?
My iPhone restarts every 2 to 3 minutes — is that still the battery?
Stop guessing why it keeps shutting off.
Walk into our Watertown, Newton, Burlington, or Wakefield shop and we'll check the battery, the port, and the connector — free — then give you a firm price before we do anything. 90-day warranty on every repair.
Or call directly: (857) 302-2655