I'm traveling from the US to Switzerland with a layover in Frankfurt / Main (Germany).
I intend to buy a laptop battery in the US for a friend's laptop. I intend to take this battery with me on the trip. As far as I know, I cannot have lithium batteries in my checked-in baggage, so I'll be carrying this battery with my carry-on baggage. However, I won't have a laptop for this battery.
Is there a possibility that this might raise an issue? I mean the fact that I'll be carrying a battery but no corresponding laptop for this battery.