It is false that batteries are not allowed in hold baggage. Provided the battery is installed in a consumer electronics device (and not just a loose spare battery), then it is fine up to 100 Wh capacity.
As for tracking devices in checked baggage, the IATA guidance states:
“Smart luggage” may contain small lithium cells or batteries with no more than 0.3 g of lithium metal or a Watt-hour
rating not exceeding 2.7 Wh that power items such as scales, locks or tracking devices. Any tracking device with a transmitting function must automatically shut down when inside the aircraft."