how to bring stuff to destination
Might depend on airline. Example Lufthansa (https://www.lufthansa.com/de/de/informationen-zur-mitnahme-von-gefaehrlichen-gegenstaenden):
Checked baggage: No
Hand luggage: Yes (1)
Checked baggage: No
Hand luggage: Yes*
Airline authorisation required: Yes
Maximum of two batteries allowed in hand luggage.
Authorisation probably only required by Lufthansa, Condor, Finnair, KLM, Suiss