Updated October 2026 by the Go Mobile repair team
A phone battery usually needs replacing when it drains fast, shuts off at 20 or 30 percent, makes the phone slow, gets hot or only works plugged in. On iPhone, check Settings > Battery > Battery Health. On Samsung, use the battery diagnostic in the Samsung Members app. A swollen battery is a safety issue: stop charging the phone and get it checked right away.
The 7 signs
- It drains much faster than it used to, even with the same apps.
- It shuts down early, at 20 or 30 percent, or when it is cold.
- The phone feels slow. iPhones can reduce performance to prevent shutdowns when the battery is worn.
- It only works plugged in.
- It gets hot during normal use or charging.
- The percentage jumps, for example from 40 percent to 5 percent.
- The screen or back is lifting. This is a swollen battery.
How to check battery health
- iPhone: Settings > Battery > Battery Health & Charging. A low maximum capacity or a “Service” message means the battery is worn.
- Samsung Galaxy: open the Samsung Members app, then Diagnostics, then Battery status.
- Other Android phones: check Settings > Battery, or ask us to test it.
Why batteries wear out
Lithium-ion batteries lose capacity with every charge cycle. Apple rates most iPhone batteries to keep about 80 percent of their original capacity after 500 full cycles, and iPhone 15 and later models after 1,000 cycles. Heat speeds up wear, so avoid leaving your phone in a hot car.
If the battery is swollen
Stop charging it and do not press on it. A swollen battery can push the screen out and, in rare cases, catch fire if punctured. Bring it in as soon as you can.
Battery replacement in Charlotte
A new battery usually brings back a full day of use and is far cheaper than a new phone. Bring your phone to Go Mobile at 5600 Albemarle Rd in East Charlotte for a free quote. Repairs are done the same day in many cases and carry a 90-day warranty.
See iPhone repair or Samsung repair in Charlotte.
Frequently asked questions
How do I know if my iPhone battery needs replacing?
Check Settings > Battery > Battery Health. A low maximum capacity, a Service message, early shutdowns or fast drain all mean it is time.
How long does a phone battery last?
Usually a few years, depending on how often you charge it and how hot it gets. Apple rates newer iPhones for about 80 percent capacity after 1,000 cycles.
Is a swollen phone battery dangerous?
Yes. Stop charging it, do not press on it, and get it replaced as soon as you can.
Will a new battery make my phone faster?
If the phone was slowing down because of a worn battery, often yes.
Battery not lasting?
Get a free quote at Go Mobile, 5600 Albemarle Rd, Suite 600, Charlotte. Walk in or book a drop-off time online.