MR-9 / SR44 / LR44 Mercury battery adaptor

A large proportion of cameras from the 1960s / 70s were designed for a Mercury battery (known as an MR-9). These are no longer available, and there are no modern batteries with the same shape.

The brass battery adaptor is the same shape as an MR-9, and enables a modern (widely available) SR44 or LR44 battery to be used instead. The battery simply slots into the adaptor (with the + terminal facing down) and then the adaptor fits in the camera.

Note that MR-9 batteries were also a slightly different voltage (1.35v) to the modern batteries (1.5v). In most cases this has a small impact on the accuracy of the camera meter but no noticeable impact on the photos. 

If you want to use a precise (original) voltage in your camera, then we suggest that you use 'Zinc Air' batteries instead of LR44 / SR44. They have a shorter life, but the same voltage as the original Mercury batteries