Spare batteries - Controlled and banned items | Cathay Pacific

What the official page says

Each passenger may carry a maximum of two lithium battery power banks. Under Hong Kong law, passengers are prohibited from: Charging power banks via in-seat power sources; Using power banks to charge or power their personal electronic devices. Additionally, power banks must not be placed in checked baggage or overhead compartments under any circumstances; they must remain securely stored in cabin baggage under the seat in front of the passenger. Spare lithium batteries must under 100 Watt-hour (Wh) / 2g Lithium content (LC). In cabin baggage 20 spare pieces allocated per passenger. Medium lithium batteries 100 - 160 Watt-hour (Wh): In cabin baggage 2 spare pieces allocated per passenger. In checked baggage: Allowed inside equipment. Large lithium batteries 160+ Watt-hour: Banned from baggage.