If a Galaxy A55 stopped charging fast after One UI 7, you are in good company. Owners in Samsung's forums said fast chargers no longer charged fast after the update, and the phone is limited to 25W anyway, so a 45W charger gives no more. Check Settings, Battery, Charging settings for Fast charging, use a charger that supports USB PD with PPS, and clean the USB-C port. If the phone will not charge at all on a known charger, the port or the battery is at fault.
Differential
Likely causes of “Samsung Galaxy A-series family will not charge or charges slowly”, and how to tell them apart
- 1
Fast charging set off after the update
What separates it Charging is slow on every charger
How to confirm Open Settings, Battery, Charging settings and switch Fast charging on
- 2
A charger without PD and PPS
What separates it It charges at a trickle
How to confirm Use a USB PD PPS charger; the A55 tops out at 25W
- 3
A dirty USB-C port
What separates it The cable works at one angle
How to confirm Lift lint out with a wooden toothpick
- 4
A worn battery
What separates it It charges but falls quickly
How to confirm Run the Samsung Members battery test
Before you touch a setting
Record this first — changing settings destroys the evidence
- Whether the slow charging began at One UI 7
- The charger's wattage and whether it lists PPS
- Whether the cable works at one angle
- The battery test result
Try in this order
0 of 3 completedCheck Fast charging
ReversibleOpen Settings, Battery, Charging settings and confirm it is on.
Change the charger
ReversibleUse a 25W USB PD PPS charger and a known cable.
Clean the port
ReversiblePower off, light the port and lift lint out with a toothpick.
Model-specific
What is true of this model and not of its siblings
- Charging
- 25W wired charging on a 5,000 mAh battery, per Wikipedia.
Stop boundary
When this stops being a self-service repair
- !If it will not charge on a known Samsung charger with a clean port, contact Samsung support
- !If the port is loose, book a port repair
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why did my A55 charge slowly after One UI 7?+
Owners in Samsung's forums reported fast chargers no longer charging fast after the update; Fast charging under Settings, Battery, Charging settings is the first check.
What is the A55's maximum charging speed?+
Wikipedia lists 25W wired charging, so a higher-wattage charger does not speed it up.
Is a 45W charger faster on the A55?+
No. Wikipedia lists 25W wired charging for the A55, so a higher-wattage charger charges it at its own 25W limit.
Does the A55 charge wirelessly?+
Samsung's A series phones do not include wireless charging, so the USB-C port is the only way to charge the A55.
How long should an A55 take to charge?+
With a 25W PD PPS charger a 5,000 mAh battery takes roughly an hour and a half from flat. A 5W phone charger can take four hours or more, which is the usual reason it seems slow.
Does it matter which cable I use?+
A USB-C cable rated for data only, or an old one with a worn plug, can charge slowly or drop out. Test with the cable that came with a Samsung phone before you blame the A55.
Is it safe to charge the A55 overnight?+
Modern phones stop drawing current when full, but heat is the risk. Charge on a hard surface, not a bed, and take off a thick case if the phone feels hot.
Can a thick case or a hot car slow the A55's charging?+
Yes. A phone that gets warm slows its own charging to protect the battery, so a thick case, a sunny windowsill or a car in summer can stretch the charge time even with the right charger. Take the case off and move the phone somewhere cool before you judge the charger.