Degraded cells in the Samsung Galaxy S21 Ultra lose capacity quietly until the phone cannot hold a useful charge. A new battery is a quick, contained fix that leaves your data untouched. We dispose of the old cell responsibly and fit a fresh one.
- Turnaround: 1 working day, subject to stock and workload
- 6-month warranty on this repair
- Walk-in near Liverpool Street Station or UK mail-in service
Signs your Samsung Galaxy S21 Ultra needs this repair
- Only reliable while plugged in
- Percentage jumping around
- Getting warm in normal use
- Slow or stalling charging
- Shutting down with charge still showing
What is included
- Safe removal of the worn battery
- Fitting of a quality replacement cell
- Charging and power-stability testing
- Full function check before handover
- 6-month warranty
How to confirm your model
Check the model number in your device settings, or bring it in and we will confirm the exact Samsung Galaxy S21 Ultra before any work begins. If you are unsure which repair you need, our team will advise.
Before you book
- If we discover water damage during your repair that affects the work, we will stop and let you know. A water damage diagnosis is applicable at the current fee, and we will confirm this with you before we proceed.
- If the screen or back is already lifting, the cell may be swollen, so book promptly and avoid charging it.
- If the device is completely dead, we run a quick diagnosis before confirming the battery.
- If the phone has had liquid exposure, a battery may not resolve everything and we check first.
Our repair process
- Book or drop in: start online or come to the Liverpool Street workshop.
- Assessment: we confirm the fault and the right part before starting.
- Repair: the part is fitted carefully and the device reassembled.
- Testing and return: a full check, then collect in store or by tracked post.
Why choose us
- Repair workshop near Liverpool Street, established since 2015
- Clear pricing with no hidden extras
- Every repair tested before it is handed back
- No data loss, this is a hardware repair
Related Samsung Galaxy S21 Ultra repairs
Frequently Asked Questions
How do I know the battery is the problem?
Fast drain, early shutdowns, only running on the charger or a swelling cell are the usual signs. We confirm before any work.
How long does it take?
Often the same day where the cell is in stock. We confirm at booking.
What should I do if the battery looks swollen?
Stop charging it and book promptly. A swollen cell can push on the screen or frame.
Is it worth replacing rather than upgrading?
If the phone is otherwise sound, a battery is a far cheaper way to get reliable all-day use again.
Do you recycle the old battery?
Yes, the old cell is disposed of responsibly.
Is the battery replacement guaranteed?
Yes. The warranty for this repair is shown on the page and applies to the fitted battery.