Old but unused NiCad batteries - already useless?

[julianm]

I`ve got some old NiCad batteries but no charger. They`re brand new but maybe 20 yrs old. Can they possibly be any good? I`d need to buy a charger to find out, so if you know about this stuff your advice would be very welcome. They`d be used in a drill/driver.
Thanks if you can help.

[Jack_and_MLE]

Measure the voltage
from memory if the cells which make up the battery are less than 0.8V each they will be dead.

Jack