Best 625 battery solution?

[mabelsound]

I've got a Pen FT coming to me shortly, and have belatedly realized that I am going to be re-entering the gruesome underworld of 625 mercury cell substitution. I gave away my remaining Wein cells last year, thinking I was done with all that!

So what's the current good solution? Is it possible to walk into Radio Shack tomorrow and walk out with the supplies needed to McGyver an adequate substitute? Or should I just order some Wein cells online and shoot with my VC meter this weekend?

[mabelsound]

Just found this:

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

Requires a bit of doing, but...I think I actually do have the parts in my workshop, and since I'm home from work with the flu I may give it a try.

[digitalintrigue]

http://bit.ly/2qEVOR

[literiter]

Originally Posted by mabelsound

Just found this:

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

Requires a bit of doing, but...I think I actually do have the parts in my workshop, and since I'm home from work with the flu I may give it a try.

This is the best way, in my opinion. I've done this to my two Weston Ranger 9s and my Gossen light meters. They work very well now, with silver oxide batteries.

[mabelsound]

Actually, for this time around, I just found an online Wein cell seller now far from where I live. But why spend $14 for a working adapter when I could spend two days burning myself repeatedly, destroying four or five alkaline 625's, and inhaling solder fumes?

One question about adapters, though--is an adapted hearing aid battery actually adequate as a replacement for mercury? Or does the metering gradually get more and more off over time?

[literiter]

Originally Posted by mabelsound

One question about adapters, though--is an adapted hearing aid battery actually adequate as a replacement for mercury? Or does the metering gradually get more and more off over time?

The best replacement is the Silver Oxide 625 version of the mercury 625. It is available.

The camera should be opened up and a 1N5711 (or similar) schottkey diode soldered in series between the battery and the camera circuit. This drops the voltage a bit. Silver cells seem to have the similar characteristics as mercury batteries in that the voltage remains relatively constant throughout it's life, but the voltage is a bit higher.

This is what I have done instead of modifying a battery. The diode mentioned is a Bat 35 which should work as well.

Try it.

The alternative, which I have never tried, would be to modify or adjust the camera circuit to accommodate the silver oxide battery.

[digitalintrigue]

In my experience the hearing aid batts work very well, they are readily available in cheap multipacks and the shelf life is quite long. Once installed they will last 3-5 months or so.

Originally Posted by mabelsound

Actually, for this time around, I just found an online Wein cell seller now far from where I live. But why spend $14 for a working adapter when I could spend two days burning myself repeatedly, destroying four or five alkaline 625's, and inhaling solder fumes?

One question about adapters, though--is an adapted hearing aid battery actually adequate as a replacement for mercury? Or does the metering gradually get more and more off over time?

[wray]

On my Olympus OM-1 the hearing aid batteries and an number 9 O-ring worked very well. Meter readings were consistent with little voltage drop off over time!

[Hibbs]

All good to know...thanks.

P.S. - These days, isn't it MacGruber?

~ Hibbs

[furcafe]

You can also still get original mercury 625s. They last a long time.

[venchka]

I didn't know about the 675 hearing aid batteries when I got a Gossen Luna-Pro with a camera purchase. I bought a pair of Wein cells. They worked fine for about a year. By the time they died, I had learned about 675 batteries. So, I separated the Wein battery from the washer that surrounded it. Presto! I had a 675 battery and a washer. In the future, I will buy 675 hearing aid batteries and put them in the Wein cell washer and Bob's your uncle! PX625 replacement.

Assuming that I ever use up my stash of real PX625 batteries. I also replaced the original Luna-Pro with a 9v powered Luna-Pro sbc.

Good luck.

[venchka]

Originally Posted by furcafe

You can also still get original mercury 625s. They last a long time.

I searched long. I searched hard. I came to the conclusion that this is an Internet myth. If you have a real source, please share with us.

Saying that they are available on ebay is not a real source.

[wlewisiii]

Originally Posted by digitalintrigue

In my experience the hearing aid batts work very well, they are readily available in cheap multipacks and the shelf life is quite long. Once installed they will last 3-5 months or so.

This is my solution for a Canon FTbN & my Gossen Luna-pro. Eventually I'll buy the Gossen adaptor, but in the meantime, the hearing aid batts are dirt cheap at Wallgreens.

William

[ItsReallyDarren]

I use 675 hearing aids with rubber sleeves I found at the electronics store for my Gossen light meter for over a year. I change them every 4 or 5 months before they go out on me.

[mabelsound]

Originally Posted by ItsReallyDarren

I use 675 hearing aids with rubber sleeves I found at the electronics store for my Gossen light meter for over a year. I change them every 4 or 5 months before they go out on me.

So that's all it takes? Just a rubber sleeve, no diode?

[venchka]

Thw Wein cells are a 675 hearing aid battery with a metal washer around it to fill up space. If using 675s, uncover one of the breathing holes. They last longer that way. You may need to let them sit for 24 hours to "come up to speed."

[nobbylon]

for a 625 adapter that drops the voltage, try this chap,
Frans de Gruijter in Nederlands and if he has them ready made they are $19 inc post
and if you are so inclined will sell you the kit to do yourself for $5
can be reached by email to battery.adapter@orange.nl

[shadowfox]

Originally Posted by digitalintrigue

http://bit.ly/2qEVOR

+1

I have three and they work really well.

[ZeissFan]

I recently saw some 625 mercury cells for sale through an Internet site. I don't remember the URL. The batteries were made in China, which should surprise no one and, of course, delves back into that previous discussion.

There are only a couple of cameras that require the physical size of the old PX13/625 battery. For most, including the Olympus Pen FT, the hearing-aid batteries and a rubber "O" ring will do the trick. And sometimes the "O" ring isn't even necessary.

Occasionally, you'll need to insert a small washer into the battery chamber.

[MartinP]

I have used the Gossen adapter, for two mercury cells, in a Lunasix meter over years without a problem. In a Leicameter-MR I use a hearing aid battery with a metal washer round it (a Wein cell imitation basically). In comparison with my last working mercury cell there was no difference, and the results also match the recently re-calibrated Gossen meter too.

Actually, it is possible that there is no need to worry about exact voltages in the MR meter, as some repair people have reported that the electronics regulate the voltage already. I have never seen a schematic though, so take that with a grain of salt.

Some pieces of equipment certainly allowed for slightly different input voltages, but the big benefit we lose from the mercury cells is the very flat discharge curve, so an ordinary alkaline battery will likely still go quickly out of controllable voltage range.

[dmr]

For the one GIII, I recalibrated it using the "wrong" 625 cell, including intentionally mis-adjusting it so it will now handle up to 1600 ISO/ASA film. That was a few years ago and since then it's been actually close enough for Kodachrome. It agrees within 1/2 stop or so with the Pentax and the "new" Gossen Super Pilot meter.

For the other GIII I've been using a Wein cell. Good, except you need to remember to re-paste the sticky over the vent hole if you're not going to be using it for a while, else the Wein cell runs down quickly.

For the Mamiya SD I simply use the "wrong" 625 without a recalibration. It's actually very close. I shot a roll of Kodachrome in it, bracketing carefully, and the "middle" one of the three was best most of the time.

[ZeissFan]

The zinc-air batteries most closely mimic the mercury and silver-oxide cells with a relatively flat voltage output but with a much shorter lifespan.

You often can buy them in 10-packs for less than US$8.

[crusius]

https://www.criscam.com/newsite/merc...y_adapters.php

[lewis44]

I searched long. I searched hard. I came to the conclusion that this is an Internet myth. If you have a real source, please share with us.

Saying that they are available on ebay is not a real source.

http://www.batteriesandbutter.com/Me...Category_Code=

[mabelsound]

Originally Posted by lewis44

http://www.batteriesandbutter.com/Me...Category_Code=

Those are seriously 625 mercury cells?