CANON EOS 1 Battery door (Insert)

Any canon film shooters on here know if the EOS 1 camera battery door and insert are interchangeable with the EOS 3 ? I recently picked up a nice EOS 3 with the large Battery Grip and I would like to also set it up with the original battery holder/grip that takes just just the one 6 volt battery. Any help will be very much appreciated. Tom

Yes the EOS 3 uses the same GR-E2 grip as the EOS 1.

Also compatible with the 1N and 1V.

You might consider using the battery pack BP-E1, which takes 4 AA batteries along with a 2cr5. Much lighter weight than the power booster, and the battery choice is switchable. You do your shooting on the AA batteries, and when they die you turn the switch on the bottom of the grip and now you're shooting with the 2cr5.