PX625 Silver Oxide Batteries

[aoresteen]

Can anyone reccomend a source for PX625 silver oxide batteries? I can find tons of akalines but no silver types. I'm in the USA.

Thanks!

 

[JCJackson]

Hi Tony,

No doubt you are looking for something to keep the meter going in the OM-1 or OM-2? The original mercury cells that these (and many other cameras and light meters of the 70s) used are no longer available - toxic mercury finding its way into land fills resulted in a ban on manufacture. The mercury cells put out a very steady 1.35 volts, and lasted a long time. You may find silver cells to replace them, but they are not quite as stable in voltage over the life of the battery, and the big problem is that they put out 1.5 volts - enough difference to result in bad meter readings.

I have a couple of vintage Nikkormat ftn cameras and Luna Pro meter that used the PX 625 mercury cells. The solution that I have adopted is using 675 zinc/air hearing aid batteries. They deliver a very steady 1.4 volt output, which is close enough to the 1.35 volt output of the mercury cells not to cause problems.

The zinc air cells are smaller in diameter than the PX 625, so I have made a ring of 18 gauge bare solid copper wire that acts as a collar on the zinc cell so it fills the battery compartment and makes electrical contact on the side - this may not be needed in some applications. Make the ring just a wee bit smaller than the battery so when you squeeze the battery in it is a snug fit.

The big draw back of the zinc cells is a relatively short life. Once you peal off the seal to let the air into the electrolyte, they are good for about 2 or 3 months in normal humidity. They dry out faster in arid conditions. I am now cutting the seal in half, and reapplying half of it to expose only 2 of the five tiny air holes - this seems to extend the life of the cells out to about 5 months.

The big plus of the zinc cells (besides the right voltage) is that they are cheap, really cheap. Right now they are on sale at CVS stores here in Pittsburgh for a price that works out to $0.50 each! So if you can deal with the hassle of replacing them a couple of times a year, this is a pretty good solution. Since the cells only activate when seal is removed (it takes about 15 minutes for them to come up to full voltage) it is easy to carry some fresh ones with your camera kit, and activate upon need.

Don't use alkaline cells - they will leak!

Good luck,

Jon

 

[puptent]

Hi, try a google search for MR-9. The MR-9 is a replacement battery shell that has a built in diode to regulate voltage, and it accepts modern silver batts. My Olympus guy sells them at around $38 <zuiko.com> and they are also available directly from the importer, (which I can't recall right now) for about the same price. I use an MR-9 in my OM-1, and it works fine, but at the next CLA I will have the diode installed directly in the battery compartment, a conversion that is included in the overhaul price at zuiko.com

 

[benjiboy]

Hi Tony,

No doubt you are looking for something to keep the meter going in the OM-1 or OM-2? The original mercury cells that these (and many other cameras and light meters of the 70s) used are no longer available - toxic mercury finding its way into land fills resulted in a ban on manufacture. The mercury cells put out a very steady 1.35 volts, and lasted a long time. You may find silver cells to replace them, but they are not quite as stable in voltage over the life of the battery, and the big problem is that they put out 1.5 volts - enough difference to result in bad meter readings.

I have a couple of vintage Nikkormat ftn cameras and Luna Pro meter that used the PX 625 mercury cells. The solution that I have adopted is using 675 zinc/air hearing aid batteries. They deliver a very steady 1.4 volt output, which is close enough to the 1.35 volt output of the mercury cells not to cause problems.

The zinc air cells are smaller in diameter than the PX 625, so I have made a ring of 18 gauge bare solid copper wire that acts as a collar on the zinc cell so it fills the battery compartment and makes electrical contact on the side - this may not be needed in some applications. Make the ring just a wee bit smaller than the battery so when you squeeze the battery in it is a snug fit.

The big draw back of the zinc cells is a relatively short life. Once you peal off the seal to let the air into the electrolyte, they are good for about 2 or 3 months in normal humidity. They dry out faster in arid conditions. I am now cutting the seal in half, and reapplying half of it to expose only 2 of the five tiny air holes - this seems to extend the life of the cells out to about 5 months.

The big plus of the zinc cells (besides the right voltage) is that they are cheap, really cheap. Right now they are on sale at CVS stores here in Pittsburgh for a price that works out to $0.50 each! So if you can deal with the hassle of replacing them a couple of times a year, this is a pretty good solution. Since the cells only activate when seal is removed (it takes about 15 minutes for them to come up to full voltage) it is easy to carry some fresh ones with your camera kit, and activate upon need.

Don't use alkaline cells - they will leak!

Good luck,

Jon

No, Wein PX 625 Zinc Air button Cells are the same size as the Mercury PX 625, Alkaline and Silver batteries.

 

[Roger Cole]

No, Wein PX 625 Zinc Air button Cells are the same size as the Mercury PX 625, Alkaline and Silver batteries.

Yes not no.

He's not talking about the Wein which IS a direct replacement but costs a few bucks each. He's talking about using the readily available and much cheaper 6*7*5 cells. Good solution if you can make it work.

 

[fstop]

The mercury cells put out a very steady 1.35 volts, and lasted a long time. You may find silver cells to replace them, but they are not quite as stable in voltage over the life of the battery, and the big problem is that they put out 1.5 volts - enough difference to result in bad meter readings.

True but 1.5v run through a diode to drop voltage to 1.35 will be pretty stable.

 

[bwrules]

Some cameras are voltage regulated and silver cells are perfect for those.

 

[mgb74]

Search for s625PX

 

[fstop]

Dead Link Removed

batterymart.com

any camera place like Adorama,BH Photo etc will have them.

 

[aoresteen]

Thanks mgb74. Located some at The Battery Mart

http://www.batterymart.com/p-s625px-silver-oxide-button-cell-battery.html

JCJAckson,

I need them for a just aquired Canonet GIII QL17.

My OM-1s use a different size silver oxide battery.

Thanks all!

 

[Venchka]

No, Wein PX 625 Zinc Air button Cells are the same size as the Mercury PX 625, Alkaline and Silver batteries.

The Wein cells that I have used are a 675 sized battery in a 625 sized washer. The battery and washer can be separated. A 675 battery fits in the washer. Try it.

I put a Wein cell in the Canonet GIII QL17 I had. Shot two rolls of C-41 film to verifiy that it worked. Promptly sold it. I couldn't see the reason for all the fuss.

Have fun!

 

[ic-racer]

The Wein cells that I have used are a 675 sized battery in a 625 sized washer. The battery and washer can be separated. A 675 battery fits in the washer. Try it.

I put a Wein cell in the Canonet GIII QL17 I had. Shot two rolls of C-41 film to verifiy that it worked. Promptly sold it. I couldn't see the reason for all the fuss.

Have fun!

Yes, save those washers. You can get loads of the 675 Zinc/Air batteries at the drug store. I think the hearing aid companies love them because they don't last very long and hopefully will keep requesting them for a long time.

 

[mgb74]

Dead Link Removed

batterymart.com

any camera place like Adorama,BH Photo etc will have them.

Actually no.

Most 625 batteries are either alkaline or zinc air, which have different characteristics than silver oxide. In some cases, alkalines will work fine. The zinc air work fine, but have a relative short lifespan. The silver oxide 625 batteries have higher voltage than the old mercury 625 batteries, but it's easier to work around than the declining voltage of the alkalines.

I haven't found silver oxide 625s at any of the "normal" photo outlets, including B&H and Adorama.

 

[wiltw]

Some cameras, like the OM-1, simply cannot take the silver oxide and meter correctly using an offset, as the degree of meter error is not merely due to battery voltage, but also related to LEVEL OF LIGHT BEING METERED! I did a test of a real PX625 (mercury) vs. a PX625A (alkaline) decades ago, in various levels of light, and found that there is NOT a single 'correction factor' (ISO offset) which could be used, as the amount of error at low light levels was very different than the amount of error at higher light levels. The MR-9 or the diode conversion, or the Wein zinc air are the proven, reliable alternatives to real mercuric oxide cells.

 

[fstop]

Actually no.

Most 625 batteries are either alkaline or zinc air, which have different characteristics than silver oxide. In some cases, alkalines will work fine. The zinc air work fine, but have a relative short lifespan. The silver oxide 625 batteries have higher voltage than the old mercury 625 batteries, but it's easier to work around than the declining voltage of the alkalines.

I haven't found silver oxide 625s at any of the "normal" photo outlets, including B&H and Adorama.

I was referring to the Wein cell

I just use the Wein cell and not worry about it.

 

[Mike Wilde]

I use a cheapo Wein zinc air cell (out of date hearing aid batterieis 2x 6 packs at a Goodwill thrift store for $1) to power the meter in a little Konica C35 Automatic Range Finder that I use in my 'make an exposure a (most) day project' that I am running from my cubicle here at the office for the last 5 months.

The meter was not responding right on Monday, so I fished out the hearing aid battery pack from the right drawer in the darkroom last night to change the battery. On the packaging I found a note that I had changed it last in May 09. I am careful to only uncover one hole when cutting the tape seal off of the bottom of the battery, and keep the lens cap on all the time I am not taking and exposure to minimize meter draw. Still this is pretty good for a fix that I though might have me changing in new cells every few months.

The hearing aid battery does not fit properly; it is not 'tall enough'. So I make a small ball of aluminum foil, and squash it to fit with the battery compartment lid as I finger tighten the battery compartment cover back into place.

I offset the film speed setting to deal with the voltage shift if I am exposing E-6 films. I have laminated a post it of the needed fix onto the bottom of the camera over where the 'use only mercury cells' label was affixed by the OEM manufacturer.

This battery fix might not be perfect, but for the purposes of the current project work, of showing how banal my working life is on a day after day basis, it works just fine.

 

[bblhed]

http://www.amazon.com/Wein-PX625-PX...VQJ7/ref=sr_1_1?ie=UTF8&qid=1302722739&sr=8-1

I have to use these in my Nikon super 8 cameras, they are 1.5V batteries mounted in a housing with a zener diode to hold it down to a 1.35V output. $5.73 each, they ain't cheep.

 

[Diapositivo]

I suggest reading this very interesting text:

http://rick_oleson.tripod.com/batt_adapt_us.pdf

I bought his adapter for my Canon Canonet 19 QL III, but I still have to buy a SR44 to be used with it.

With this solution, you use a common silver battery and you buy the diode just once.

I had my Minolta Srt100x and Minolta Srt101 modified in 2006 to use a common AG13 (LR44, that's alkaline) battery. I think the repairer installed some voltage regulator inside but I have lost his contact details so cannot give you more precise details. I suppose I could use SR44 batteries (silver) with identical light measurements.

Fabrizio

 

[aoresteen]

Update:

I ordered five PX625 silver oxide batteries from The Battery Mart. The ones I got were all bad. Four were 1.27v, one was 1.17v. I called them and they sent me an RMA label to return them (they paid the postage). We'll see if the replacements are any better.

 

[Gerald C Koch]

I havr always been able to get them from my local CVS pharmacy. Also try the watch section of department stores or Radio Shack.

 

[mgb74]

What brand were they?

Update:

I ordered five PX625 silver oxide batteries from The Battery Mart. The ones I got were all bad. Four were 1.27v, one was 1.17v. I called them and they sent me an RMA label to return them (they paid the postage). We'll see if the replacements are any better.

 

[Peter Simpson]

I have a Canonet, and an SR44 fits in the battery holder just fine. Mine now reads the same as two other meters (D700 and a Gossen LunaPro SBC), so I did not need to do this, BUT, the Canonet GIII QL17 has a trimmer resistor which can be tweaked to compensate for the difference in voltage between the mercury and silver batteries. So, if you're comfortable opening up the top and messing with the variable resistor, you could save $40.

 

[aluncrockford]

You might want to try these people

http://www.smallbattery.company.org.uk/

 

[aoresteen]

What brand were they?

I'm not sure. I didn't notice the brand. They were in plain small plastic bags with a computer label on them. I sent them back yesterday so I can't check.

 

[aoresteen]

Thanks mgb74. Located some at The Battery Mart

http://www.batterymart.com/p-s625px-silver-oxide-button-cell-battery.html

JCJAckson,

I need them for a just aquired Canonet GIII QL17.

My OM-1s use a different size silver oxide battery.

Thanks all!

Actuly it is a QL17, 2nd gerenation circa 1969-1970. It is not a GIII. Sorry for the error.