In uk.d-i-y Mr Fixit wrote:
as header I have a shaver that has NH on the battery is this the same as a
NiHm battery, as the spare is ?14 if you can get one for the sake of one AA
cell

Almost certainly.
The worst that can happen if it's wrong is that it explodes showering
you with hot caustic electrolyte.
Though this is vanishingly unlikely.

Does it give a capacity?
If so, and it's 900mAh, it's NiMH