It’s one of the most common conversations we have at Phone Heroes. Someone comes in ready to buy a new Samsung, convinced their current phone is on its last legs. Nine times out of ten, the phone is perfectly fine — it’s just the battery that needs replacing.
Battery degradation is a normal part of owning a smartphone. Every lithium-ion battery has a finite number of charge cycles, and after a couple of years of daily use, performance starts to slip. The good news is that a battery replacement is one of the quickest and most affordable repairs you can have done — and it can make a phone that feels sluggish and unreliable feel brand new again.
Here are five clear signs that your Samsung battery needs replacing.
1. Your Phone Dies Long Before the End of the Day
If your Samsung used to easily last a full day on a single charge but is now dead by mid-afternoon — even with normal use — battery degradation is almost certainly the cause. As a battery ages, its capacity to hold a charge reduces. A battery that once had 4,000mAh of capacity might only be delivering 2,500mAh after two years of heavy use. No amount of turning off Background App Refresh or lowering screen brightness will fix a battery that can no longer hold a meaningful charge.
2. The Battery Percentage Drops Suddenly
Does your Samsung show 40% battery and then drop to 15% within minutes? Or does it shut down unexpectedly while still showing charge remaining? This is a classic sign of a degraded battery that can no longer accurately report its own charge level. The battery management system relies on the battery performing within expected parameters — when it can’t, the readings become unreliable and the phone shuts down to protect itself.
3. The Phone Gets Unusually Hot During Charging or Use
All phones produce some heat during charging and processor-intensive tasks. But if your Samsung is getting noticeably hot — not just warm — during normal use or while on the charger, the battery may be working harder than it should to compensate for reduced capacity. In some cases, excessive heat during charging can also indicate a problem with the charging dock rather than the battery itself, so it’s worth getting both checked.
4. The Phone Takes Much Longer to Charge Than It Used To
A significantly longer charging time — particularly if you’re using the same charger and cable as always — can indicate a deteriorating battery. As cells degrade, they can struggle to accept a charge at the normal rate. If you’ve already ruled out a faulty cable and the problem persists, the battery is the most likely culprit.
5. The Back of Your Phone Looks Slightly Raised or Bulging
This one is urgent. If the back of your Samsung has started to bow outwards or the screen is being pushed away from the body slightly, stop using the phone immediately and bring it in for repair. A swollen battery is a sign of internal gas build-up and poses a genuine safety risk. Do not attempt to charge a phone with a swollen battery. At Phone Heroes, we can safely remove and replace a swollen battery — but please do not delay if you notice this symptom.
How Long Does a Samsung Battery Replacement Take?
At Phone Heroes London, a Samsung battery replacement typically takes around 45 minutes. We carry stock for a wide range of Samsung models — from the Galaxy S-series through to the A-series and J-series — and we use quality replacement batteries that come with our standard One-Year Warranty.
It’s a fraction of the cost of a new phone, and in most cases, once the battery is replaced, the device performs just as well as it did when it was new.
Still Not Sure? Come In for a Free Diagnosis
If you’re not certain whether the issue is the battery or something else, bring your Samsung into our Earl’s Court store. Our technicians will carry out a free diagnosis and let you know exactly what’s wrong before recommending any repair. No hidden charges, no pressure — just honest, expert advice.
We’re open 7 days a week. Call us on 020 3397 7407 or use our online booking form to reserve a time that suits you.