The Yoga 9i 2-in-1 Gen 9 charges over USB-C, and it has two Thunderbolt 4 ports, so a charging problem often comes from the cable and the adapter as much as the laptop. The laptop expects a charger of about 65 W; a phone charger or a 30 W adapter lets it run slowly or not charge while it is busy, and a USB-C cable that is not rated for the power does the same. Try the original Lenovo adapter and cable, and try the other USB-C port, since one port can fail.
Look into the port for lint. The charging indicator and the battery icon tell you the state: Plugged in, not charging can mean Battery Conservation mode in Lenovo Vantage is holding the charge at a threshold, which is deliberate.
A power drain, holding the power button for sixty seconds with everything unplugged, resets the charge controller, and BIOS and Vantage updates fix known charging bugs. A laptop that charges from one port but not the other points at a port fault, and a laptop that charges but loses charge under load points at the adapter's wattage. Charging through a dock can deliver less than a direct charger, so test directly. Windows also lets you see the charger's wattage in the Lenovo Vantage power page, and a reading far below the charger's rating means the cable or the port is limiting power. Compare the reading with another cable to identify the weak part.
Differential
Likely causes of “Lenovo Yoga 9i 2-in-1 Gen 9 will not charge”, and how to tell them apart
- 1
A low-power adapter or cable
What separates it The laptop does not charge under load
How to confirm Use the original 65 W adapter and a rated cable
- 2
The wrong port
What separates it One port does not charge
How to confirm Try the other USB-C port
- 3
Battery Conservation mode
What separates it It stops at about 60 percent
How to confirm Lenovo Vantage: turn it off
- 4
A stuck charge controller
What separates it Plugged in, not charging
How to confirm Unplug everything and hold power sixty seconds
- 5
Lint or a damaged port
What separates it The plug is loose
How to confirm Clean the port and contact Lenovo if bent
Before you touch a setting
Record this first — changing settings destroys the evidence
- The charger and cable used
- Which port is used
- Whether Conservation mode is on
- The battery icon message
Try in this order
0 of 8 completedUse the original adapter and cable
ReversibleA charger of about 65 W with a cable rated for it.
Try the other USB-C port
ReversibleTest both Thunderbolt 4 ports.
Check Conservation mode
ReversibleLenovo Vantage, Device, Power.
Do a power drain
ReversibleUnplug everything, hold power for sixty seconds, then plug in the charger.
Check the port
ReversibleLook in with a flashlight for lint.
Update the BIOS
ReversibleCharging fixes arrive with BIOS updates.
Test charging directly without a dock
ReversiblePlug the charger straight into the laptop.
Watch the battery under load
ReversibleIf it falls while plugged in, the charger is too weak for the load.
Model-specific
What is true of this model and not of its siblings
- USB-C power
- The wattage and cable both matter.
- Two ports
- One can fail while the other works.
- Docks
- They can deliver less power than a direct charger.
- Load
- Heavy use can outrun a weak charger.
Stop boundary
When this stops being a self-service repair
- !If it will not charge on the original adapter in both ports, contact Lenovo
- !If a port is loose, it needs repair
- !A hot charger means stop
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why doesn't my Yoga 9i charge?+
A weak charger, a port problem or Conservation mode.
What charger does it need?+
About 65 W over USB-C.
Can I use a phone charger?+
It may run but not charge.
Which port should I use?+
Either Thunderbolt 4 port.
Why does it lose charge while plugged in?+
A charger of too low wattage.
Can a dock charge it?+
If it supplies enough power.