Service 000154 Mercury Battery Adapter Converter Type MR-9 (H-D) Adapter for KANTO Cameras

Worked perfect to use a modern battery in my vintage Canon FTb’s!

Nice solution to an old problem.

I tried this adapted in my Olympus OM-1n and it did not work, the voltage only marginally reduced and was far higher than that of the mercury battery that it was supposed to replace. The problem is that it needs a 10k ohm or lower resistance to work and the OM-1n presents a higher load resistance than this so it does not function properly. The instruction sheet with the adapted is in Japanese, translating this it does mention that it needs a 10k load to work. This needs to be clearly stated on the Amazon description page. I suspect that the adapted design has changed over the years as there are cases where people state that it works with their OM-1 cameras.

I’m not sure if I received a faulty product or if it just doesn’t actually work, but after testing the converter with a multimeter, it only drops the voltage of the battery by .05v. So the 1.55v battery is only dropping to 1.50v, not the advertised 1.35v. The light meter in my camera is pretty accurate regardless (I’ve had several rolls come out just fine with this converter in my camera), but saving money and buying just a battery size adapter without the diode seems like a better way to go.