Signs Your Phone Battery Needs Replacing
Signs Your Phone Battery Needs Replacing
Signs Your Phone Battery Needs Replacing
Your phone used to last all day. Now it barely makes it to lunchtime. Before you start blaming the latest software update or shopping for a new phone, there’s a good chance the real problem is simpler – your battery is worn out.
Here are the warning signs to look for, and what you can do about it.
The Warning Signs
1. It Drains Much Faster Than It Used To
This is the most common sign. If you’re charging your phone twice a day when it used to last until bedtime, the battery is losing its ability to hold a charge. It’s not your imagination – batteries genuinely degrade over time.
2. It Shuts Down Before Reaching 0%
Your phone says 20% and then just dies. Or it switches off at 15%, 30%, sometimes even higher. This happens because the battery can no longer accurately report how much charge it has left. The percentage on screen becomes unreliable as the battery ages.
3. The Battery Is Swollen or Bulging
This is the most serious sign. If the back of your phone feels raised, the screen is lifting away from the frame, or the phone won’t sit flat on a table anymore, the battery may be swelling. Stop using it immediately. A swollen battery is a safety risk and needs professional replacement as soon as possible.
4. Your Phone Gets Very Hot
Some warmth during heavy use is normal. But if your phone gets uncomfortably hot during basic tasks – texting, scrolling social media, making calls – that’s a sign the battery is working harder than it should. Excessive heat also accelerates further battery degradation, creating a vicious cycle.
5. Performance Has Slowed Down
Both Apple and Samsung throttle your phone’s processor when the battery degrades past a certain point. This is actually a safety feature – it prevents unexpected shutdowns. But it means your phone feels sluggish and apps take longer to open. A new battery can restore the speed you’ve been missing.
6. It Won’t Charge Past a Certain Percentage
If your phone charges to 80% or 90% and then stops, or if it takes hours to go from 80% to 100%, the battery cells are struggling. This is different from optimised charging features (which intentionally pause at 80% overnight) – if it happens during the day when you’re actively charging, it’s a battery problem.
How to Check Your Battery Health
You don’t need to guess. Both iPhone and Samsung give you a way to check.
On iPhone
Go to Settings > Battery > Battery Health & Charging. You’ll see a “Maximum Capacity” percentage. A new iPhone shows 100%. As the battery degrades, this number drops.
On Samsung
Go to Settings > Battery and Device Care > Battery. On newer Samsung phones, you can also use the Samsung Members app – open it, go to Support, then Diagnostics, and run the battery test.
The 80% Rule
The industry standard threshold is 80%. When your battery’s maximum capacity drops below 80%, it’s considered worn and due for replacement. Apple even displays a “Service” message at this point. You’ll notice the difference in daily use well before it hits 80%, though – most people start feeling the impact around 85%.
Why Batteries Degrade
Phone batteries are lithium-ion, and they have a limited number of charge cycles. One cycle is a full discharge from 100% to 0% (or two half-cycles from 100% to 50%). Most phone batteries are rated for around 500 to 800 full cycles before significant degradation.
If you charge your phone once a day, that’s roughly two years before the battery starts to noticeably decline. Charge it twice a day and you’ll get there in about a year.
Other things that speed up degradation:
- Heat – Leaving your phone in direct sunlight or using it while it’s charging and getting hot.
- Extreme cold – This one matters in St Andrews. Cold weather temporarily reduces battery capacity and can cause unexpected shutdowns.
- Charging to 100% constantly – Keeping the battery between 20% and 80% extends its lifespan, though most people don’t bother with this.
- Using cheap chargers – Non-certified chargers can deliver inconsistent power that stresses the battery.
St Andrews Weather and Your Battery
Living on the east coast of Scotland means cold, damp conditions for a good chunk of the year. Lithium-ion batteries perform worst in the cold – the chemical reactions inside slow down, reducing the available charge. If your phone dies on a freezing walk along the West Sands and then works fine once you’re back indoors, cold is the culprit.
But if it’s dying indoors too, that’s a genuine battery problem – not just the weather.
What Does a Battery Replacement Involve?
A phone battery replacement is one of the most straightforward repairs we do. We open the phone, carefully disconnect the old battery, fit a new one, and test everything before handing it back.
For iPhones, iPhone battery replacement typically takes 30 to 45 minutes. Samsung and other Android phones are similar – usually done within the hour.
Prices range from £49 to £119 depending on the model. That’s a fraction of the cost of a new phone, and it genuinely makes your current phone feel new again.
Don’t Buy a New Phone Just Because the Battery Is Tired
A worn battery doesn’t mean a worn phone. If your device is still getting software updates and runs the apps you need, a battery replacement gives it another two years of life for under £120. It’s one of the best value repairs you can get.
Repair St Andrews, 1 City Rd, St Andrews, KY16 9XQ. Call 01334 478866 or walk in. Open Monday to Friday 09:30-17:30, Saturday 10:00-17:00.
