Mercury battery OM-1n replacement

[vaantique]

I bought a very nice OM-1 the other day with 3 different lenses and a hefty flash. After checking the thing up

and down and looking through all the manuals I realized it takes a mercury cell. After searching to see what

options there are for replacement I've settled on adapting it to Silver oxide cells using a Schottky diode to

lower the voltage. Has anyone done this or used any other satisfactory methods to use modern batteries?

I was thinking that I could simply remove the bottom cover and solder the diode on the positive lead wire going

to the battery connection and then make an adapter for whatever size silver battery would fit the easiest. Zinc

air batteries are not on the table since they tend to go bad quickly by their nature and poor performance

reported by other people.

[richard_oleson]

Well, if they're not on the table they're not on the table. I've never gotten less than 6 months out of one, and the

longest went 27 months... typical life for me is about 8 months. If you don't like the Z/A route, I would suggest a

CRIS adapter rather than doing surgery on the camera for the same effect.

 

The size of silver cell that fits the easiest is the same as the size of the Z/A cell: the 44/76/675/357 cell. Without the

CRIS adapter, it's not a great fit; you can make it fit with an O-ring, or the emptied shell of a 625A alkaline cell.

 

The CRIS adapter costs about $30, which for me is less than I would want to be paid for soldering the diode into the

camera; and you can get a pack of three 357 silver cells for about $5 or so. The Z/A cells cost less than a dollar.

[patrick j dempsey]

Since 6 months is about what I get out of the more expensive silver oxide cells in my OM4, I don't consider 6 months to be poor life for a very very cheap zinc-air cell. The only poor performance I have heard about is some of the more expensive Wein zinc-air cells which seem to be the incorrect voltage and cause metering issues... this is apparently an erratic problem and not true of all samples. I have not noticed the same problem with #675 hearing aid zinc-airs, which I use in several different cameras rated for mercury cells.

[William Kahn]

I've been using Wein air cells in my OM-1 for about 3 years with no problems, metering or otherwise. The last one lasted about a year. I always buy two, in case the "oops" happens in the field. It helps to turn the meter off when done shooting.....

[john_hermanson2]

When I convert OM-1/1N meters to silver oxide battery (MS76, 357, SR-44W, G-13) I use 1N-6263 schotkey diode. There are others that will work. Some OM-1 battery contacts are held in with a plastic screw so I suggest not trying to solder the diode directly to the battery contact. Also, contact is stainless steel and can be difficult to solder to in general. John, www.zuiko.com

[neild]

As someone who has/uses the adapter, I say it is wonderful and I wouldn't want to do it any other way (and now all my OM bodies take the same batteries!).

[vaantique]

Where do you all buy your diodes for the conversions? I've searched online and all I've found is datasheets.

The reason I don't want to use zinc air is I'm probably going to leave this camera for long periods without using it, and the nature of these cells is they are meant to be used in constant drain devices like hearing aids and they are meant to be replaced regularly.

[john_hermanson2]

Yes, I should have mentioned that the MR9 adapter w/386 battery (which I sell) is the ideal drop-in conversion. John, www.zuiko.com

[richard_oleson]

I have a little bag of 10 of them stuck to the bulletin board next to my bench, still unopened. They've been hanging there for years and I have yet to come up with a reason to open the bag.... the ZA cells and MR9 adapter are just so much easier and don't involve carving up a nice classic camera.

[User_502260]

I have two MR-9 adapters. Right now one is in a Canon F-1 and the other in a Canon FTbN. At some point I might get another one or two of them for other cameras. My Olympus SLR cameras are all OM-10s. This is the Rodney Dangerfield of Olympus OM cameras. One of my OM-10s has a problem with infinity focus and a crack in the top, one works perfectly and one needs a CLA. The MS-76 seems to last forever in an OM-10. I would use the MR-9 in some of my Nikkormat FTNs but it's just easier to use an FT2 or FT3 with the MS-76. I use the 675 ZA hearing aid batteries in my Konica Autoreflex T and A series cameras. I did use them for a while with a rubber O ring in a Canon FT QL but the MR-9 is really easier.

[steve_bellayr]

I, too, went with the Criscam adaptor. Much easier & you can switch it to another camera.

[User_4525289]

Marshall, get hearing aids 1.4 battaries. They are available everywhere that did the trick with my Olympus OM1n.