They won't work with inductive loads - the transformer in the charger,
in this case.
Murray vk4aok

Pierre wrote:

Greetings..

... I plan to use a battery charger in Europe (220V 50 Hz). I will
have a Radio Shack 273-1413 (Canadian model) foreign travel voltage
converter.

However, I see on the back of that device that it should not be used
with a battery charger.

What is the reason for this?

Thanks de F/VE2PID