Battery replacement explained: when you need one and what happens

Signs you need a new battery

• Battery health at or below about 80%, or a “Service” message on iPhone.
• The phone switches off at 20–30%, especially in the cold.
• The percentage jumps around – 40% to 10% in minutes.
• It only works when plugged in.
• The phone feels slower than it used to (iPhones can slow down to prevent shut-downs on a worn battery).

Check yours first: how to check battery health.

What happens during a replacement

1. Free check: we test the battery and confirm it’s the cause – and the price – before starting.
2. Opening: modern phones are sealed with adhesive. We warm and carefully separate the screen or back glass with proper tools.
3. Disconnecting: the battery is disconnected first so nothing can short.
4. Removal: the old battery is held in with stretch-release adhesive strips. We remove it without bending or puncturing it.
5. New battery and seal: the new battery is fitted and the phone is resealed with fresh adhesive.
6. Testing: we check charging, battery readings and every other function with you before you leave.

Things to know

• Your data: stays on the phone. We still recommend a backup before any repair.
• Water resistance: opening any phone affects its original water seal. We fit new adhesive, but treat the phone as less water-resistant than when new.
• iPhone messages: some iPhones show an “unknown part” or “unable to verify” notice after a battery change by a shop that isn’t Apple. It doesn’t affect how the battery works; we explain this before we start.
• Warranty: our battery replacements come with our 1-year repair warranty.

Is it worth it?

For most phones less than five or six years old, yes – a battery costs a fraction of a new phone and can give you another couple of years of use.