Batteries for Magnetometers question

[Unregistered]

Hi all,
I know that it is ok to use a Gel Cell or sealed lead acid battery with a mag because it is non-ferrous. Is a Nimh battery pack suitable as well or does it contain ferrous material? I'm interested due to the reduced weight of the Nimh pack.
Thanks

[Unregistered]

Question answered

Well I guess I have answered my own question. Put a magnet up to a battery and it sticks :-(