Start with evidence
Run the tests that separate the likely branches
Charger Wattage MatchCompare a device's entered power requirement with a charger's rated wattage while keeping USB-PD/PPS and voltage-profile limits explicit.
Run →USB-C Cable Power Rating CheckCompare an entered cable wattage rating with the power you want to carry, while keeping protocol/e-marker limits explicit.
Run →Battery Charge Time CalculatorEstimate battery charging time from energy capacity, charger power and entered charging efficiency.
Run →Decision table
What the observation changes
ObservationWhat it meansNext action
Phone charges normally but not at the expected fast modeBasic power path works; charger/profile/cable are higher priority.Use a known Samsung-compatible high-power adapter/cable.
Fast charging appears only at low batteryNormal charging taper can explain reduced power later.Compare over the same low-to-mid charge window.
Charging disconnects when cable movesMechanical cable/port condition is higher priority.Stop stressing the connector and test another cable; inspect/service if repeated.
Sequence
Work from reversible checks to escalation
- 01
Check adapter's supported USB-C output/profile.
- 02
Use a high-current known-good cable.
- 03
Test while the phone is cool and not under heavy load.
- 04
Compare from a low battery state.
Likely areas
Keep these branches separate
Adapter profile/wattageCable current capabilityThermal throttlingBattery stateUSB-C connector
Repair boundary
When to stop changing settings
Stop if connector/battery area becomes abnormally hot or the port is loose/damaged; use Samsung service.