Mamiya 7II: Energizer A544 Battery Warning, Part 2
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
I did a post on this issue a little while back but feel that I need to do this again and in more detail as it is causing issues for Mamiya 7II owners. While I would like to believe that everyone who owns a Mamiya 7II is following me and reads my posts, the reality, of course, is different. So- If you have a Mamiya 7II, this is an urgent plea about batteries. Specifically the Energizer Alkaline A544. Please do not buy this battery as it will not work on your camera. I am getting a deluge of cameras coming into the shop and also emails about inoperative Mamiya 7IIs after putting in a brand new battery. The battery in questions is always the Energizer A544.
The details: starting in May 2000 (date code TE), Mamiya added plastic to the top of the battery cover to prevent possible battery drain when contacted by the hand of the user. The first photo shows the metal cap (pre May 2000) and the second photo shows the plastic covered one.
Photo three shows both caps with the plastic covered one on the right. Visible are the four small plastic pins holding the cover in place. Also, the root of the problem can be seen- in the center of the cap in the round raised portion there is a plastic piece with a plus sign. This is what presses against the raised part on the battery positive terminal.
The first photo shows the battery with the raised nipple. The battery cover contacts this part and insulates the battery positive from the frame of the camera and then we have a no power situation.
So far I have only seen this on the Energizer A544 battery and it seems to be a new development. No idea why this is done, every other battery has a flat contact.
To my knowledge, this battery is only causing a problem for the Mamiya 7II. So, it does not seem like the company making these batteries would be that concerned about it not working on a camera that has been discontinued for over a decade.
