Tway Air power-bank flight policy.

Short answer

Tway Air publishes readable official restricted-item guidance: power banks are treated as spare batteries, spare batteries are carry-on only, power banks up to 100 Wh are capped at two units, 100-160 Wh lithium batteries require airline approval with a two-unit cap, over-160 Wh batteries are not transported, power banks must be carried directly rather than stored in overhead bins, passengers may not charge power banks or use them to charge devices in flight, and power banks must be individually packed or terminal-protected.