I’d go a different route… basic law of systems design, the more components, the more points of failure.
Wire the whole train for power pickup, run power to the rails, and you are done.
No matter where the layout is, it will need occasional cleaning, battery or not, there will be stuff falling on the track outside, and inside, dust and other contaminants in the air.
Many LGB-based display layouts have run until they have worn the flanges off the wheels or half the railhead off.
If you want a charging system that relies on a dock, you just added another point of failure.
If you want inductive charging, you can do this, less moving parts, but the system won’t be off the shelf, so another custom design with unproven long term reliability.
Greg