PX27M battery not working in my Rollei A110?
I recently inherited a Rollei A110 from my grandpa who has sadly passed away. To get it running I bought a PX27M battery because that's what pretty much every blog or video talking about the A110 recommends as a replacement for the original V27PX mercury batteries.
When I opened the battery compartment an old mercury battery that my grandpa must have put there in the 80s or 90s came tumbling out. Comparing this battery to the PX27M I noticed that the poles are the other way around. On the new battery the + is on the button side and the - on the flat side. When I place the new battery in the compartment it doesn't make contact since the flat side doesn't protude past the casing. I'm a bit stumped because I can't find anyone talking about this online.
The old battery must still have some juice because when I put it in I get the blinking green light that indicates slow shutter speed. With the new battery I get nothing. I don't exactly want to risk shooting a roll with a decades old battery though since it might mess up the exposure.
Does anyone have any idea why the PX27M is not working for me?