An S24 Ultra that charges slowly is usually waiting on the charger. Samsung's 45W Super Fast Charging 2.0 needs a charger with USB Power Delivery 3.0 and PPS, and owners in Samsung's US forum note the phone ships with a cable and no wall adapter, so many people are charging on an old phone charger that tops out far below 45W. GSMArena lists 45W wired charging to 65 percent in 30 minutes and 15W wireless. If it will not charge at all, try a Samsung charger in a wall outlet, look in the USB-C port for lint and run Samsung's checks from the charging settings.
Differential
Likely causes of “Samsung Galaxy S24 family will not charge or charges slowly”, and how to tell them apart
- 1
An old or generic charger
What separates it It charges, but the percentage climbs slowly and the screen does not say Super fast charging
How to confirm The 45W mode needs a PD 3.0 PPS charger; a phone charger from a few years ago gives 10 to 25W
- 2
No wall adapter in the box
What separates it A new S24 Ultra is charging from a computer port or a weak brick
How to confirm Samsung's US forum notes the phone ships with a cable only, so the first charger is often an old one
- 3
Fast charging switched off or the screen on
What separates it Charging is slow while you use the phone
How to confirm Super fast charging runs best with the screen off; check Fast charging under Settings, Battery, Charging settings
- 4
A dirty or worn USB-C port
What separates it The cable feels loose or works only at one angle
How to confirm Shine a flashlight in the port and lift lint out with a wooden toothpick
Before you touch a setting
Record this first — changing settings destroys the evidence
- The charger's wattage and whether it lists PD and PPS
- What the lock screen says while charging
- Whether the phone charges on a different cable and outlet
- Whether wireless charging works
Try in this order
0 of 5 completedCheck what is plugged in
ReversibleRead the charger's label. A 45W PD PPS charger is the one that gives Super Fast Charging 2.0.
Try a wall outlet and a second cable
ReversibleAvoid computer ports and car adapters for a fault test.
Check the setting
ReversibleOpen Settings, Battery, Charging settings and confirm Fast charging is on.
Clean the port
ReversiblePower off, look in the USB-C port with a flashlight and lift lint out with a wooden toothpick.
Test wireless
ReversibleIf a wireless pad charges it and the cable does not, the port is at fault.
Stop boundary
When this stops being a self-service repair
- !If a known Samsung 45W charger gives no charge and the port is clean, contact Samsung support with the charger model
- !If the cable wobbles in the port, book a port repair
Evidence ledger
Sources behind this answer
Owners on the charger not being in the box.
An owner whose phone ignores a 45W charger.
45W wired (65 percent in 30 minutes) and 15W wireless.
Exact questions
Common questions
Why doesn't my S24 Ultra charge at 45W?+
It needs a PD 3.0 PPS charger; an older charger limits the speed. In the US the phone ships with a cable and no wall adapter.
How fast should it charge?+
GSMArena lists 65 percent in 30 minutes at 45W and 15W on a wireless pad.
Does the screen matter?+
Super fast charging is fastest with the screen off or Do Not Disturb on.
Why does a charger that works on my old phone charge the S24 Ultra slowly?+
Older chargers lack PPS, the programmable power supply that the 45W Super Fast Charging 2.0 mode needs, so the phone drops to a slower profile.
Is wireless charging on the S24 Ultra fast?+
GSMArena lists 15W wireless charging and 4.5W reverse wireless charging, slower than the 45W wired rate.
What does Protect battery do?+
Samsung's Protect battery setting limits charging to 80 or 85 percent so the cell ages more slowly, and the phone reports full at that level.
How can I tell the S24 Ultra is charging at full speed?+
The lock screen names the mode while the charger is connected. Samsung shows Super fast charging when the 45W mode is active, and plain Charging when it has fallen back to a slower profile.