Lenovo's hardware maintenance manual covers its battery, storage and other service parts across machine types 21HD, 21HE, 21K3 and 21K4.
What to check before buying
Service documentation
The linked Lenovo maintenance manual is specific to the T14 Gen 4 and P14s Gen 4 family. It is more useful for component matching than a generic ThinkPad T-series guide.
Configuration
The iFixit device entry identifies four T14 Gen 4 machine types. Battery and board compatibility should be checked against that type before selecting a used unit or part.
Sources
- ThinkPad T14 Gen 4 Repair HelpiFixit
- ThinkPad T14 Gen 4 hardware maintenance manualLenovo / iFixit