imokruok
Well-known
Yeah, the Wein cells seem to have a pretty short life for me as well. Although I found some of the same cells under the Kodak brand at Adorama, I think. (They're probably just licensing their name to some Chinese generic manufacturer.) Anyhow, that was the first time I'd seen those cells under another brand, so I will try them out when my next Wein runs out.
Leigh Youdale
Well-known
If all those people commenting in this thread on zinc oxide hearing aid cells had bothered to download the technical paper I linked to in my earlier post you would have had the answers. Yes they work. Yes, they require air to function and no, they don't last all that long after the paper seal is removed. No, the voltage drop off is NOT the same as mercury cells - neither are any alkaline or lithium batteries such as Axxx type or Lxxx type. Silver oxide (SR) show the same characteristic curve as mercury cells - constant voltage until right at the end of their life. The others degrade progressively - which may or may not affect the accuracy of your meters depending on whether the camera manufacturer built in some correction.
Considering the SR44's cost less than $3 and the proper adaptor is a one-off cost of 16 Euros, why put up with a compromised solution?
xwhatsit
Well-known
Leigh, check this link and scroll down most of the page for discharge curves: http://rick_oleson.tripod.com/index-111.html . As you can see, the zinc-air has an almost identical discharge curve to mercury. This is why they're used in hearing aids as well (which used to use mercury batteries for the same reason they were used in voltage reg-less meters). The only difference is, as you state, poor life (6 months whether used or not), and the need for breathing.
6 months is more than enough life out of a battery for me. I bought 12 hearing-aid zinc-air cells for less than $NZ10, so I'm not complaining.
My Yashicas which take the mercury battery all have air holes so this isn't an issue. Interestingly, the only obvious difference between the Wein cells and ordinary cheap hearing-aid batteries is less air holes in the battery itself -- two vs. four. This is supposedly to make them last a bit longer.
6 months is more than enough life out of a battery for me. I bought 12 hearing-aid zinc-air cells for less than $NZ10, so I'm not complaining.
My Yashicas which take the mercury battery all have air holes so this isn't an issue. Interestingly, the only obvious difference between the Wein cells and ordinary cheap hearing-aid batteries is less air holes in the battery itself -- two vs. four. This is supposedly to make them last a bit longer.
gdi
Veteran
I use the hearing aid batteries and I trim the paper sticker to expose only 2 holes, they seem to last much, much longer than those with the complete sticker ripped off.
charjohncarter
Veteran
Totally agree, use the proper method of disposal. BUT in my previous life I used Mercury in my business, and Mercury hygiene was a very important part of our daily life (from 1969 to 1980). So when I moved, the county that I moved to requested information on my Mercury disposal. One thing that I thought was interesting was they somehow could tell how much Mercury came from where.???????? The totals of Mercury going though the county water treatment plant was extremely small (I live in the Bay Area near San Francisco). The largest Mercury numbers was still from water that was somehow still coming from Gold mining run off from 1849 (by far 50 to 1, if not higher). Thermometers that were broken and people that lost fillings were the second and third largest amounts. These second and third amounts were extremely small. Hygiene of Mercury use is of course important but sometimes I think the people running these programs can't do math.
laoyou
Member
flip
良かったね！
Can find these pretty readily in Japan - even via auction. Seems the locals forgot that whole Minamata disease photo essay.
W
wlewisiii
Guest
I just buy big packs of zinc-air hearing aid batteries. They have an even shorter lifespan than the Wein cells but they're dirt cheap ($11 for 8 at Wallgreens) so I can toss them every month or two without worry and they feed my Gossen just fine.
William
William
Vincenzo Maielli
Well-known
I solved the PX625 battery problem with the Kanto MR9 adapter. Work nicely.
Ciao.
Vincenzo
Ciao.
Vincenzo
Kim Coxon
Moderator
Just a thought to clear up any misunderstanding.
The voltage and discharge curve of any battery depends on the chemical reaction taking place. The chemical reaction in zinc/air or wein cells is exactly the same as mecury batteries. (A wein cell is a zinc/air with smaller holes so it takes longer to dry out
)
The only difference between to two types is that in the mercury batteries, the oxygen for the rection came from mercuric oxide. In zinc air/wein cells it comes from the atmoshere through the holes
For Pentax cameras, you can safely use silver cells as they work ona whetsone bridge principle and so are not that voltage dependant. For other cameras, the MR9 and other adapters or indeed a fix to re-calibrate the meter works just as well.
Bearing in mind most of the meters using mercury cells are at least 40 years old, the LDR's are likely to be more "out" than any minor difference in voltage. In empiracal terms, the actual reading may not be indentical but bearing in mind we are talking cameras where you can only set the shutter speed to the nearest full stop, there is little or no practical difference. In any case most "inbuilt" meters are not that accurate anyway and are easily "fooled" by light conditions
With hand held meters, it may be slightly different but is still likely to be within a 1/10 stop and well within the lattitude of even E6 film.
Kim
The voltage and discharge curve of any battery depends on the chemical reaction taking place. The chemical reaction in zinc/air or wein cells is exactly the same as mecury batteries. (A wein cell is a zinc/air with smaller holes so it takes longer to dry out
)The only difference between to two types is that in the mercury batteries, the oxygen for the rection came from mercuric oxide. In zinc air/wein cells it comes from the atmoshere through the holes
For Pentax cameras, you can safely use silver cells as they work ona whetsone bridge principle and so are not that voltage dependant. For other cameras, the MR9 and other adapters or indeed a fix to re-calibrate the meter works just as well.
Bearing in mind most of the meters using mercury cells are at least 40 years old, the LDR's are likely to be more "out" than any minor difference in voltage. In empiracal terms, the actual reading may not be indentical but bearing in mind we are talking cameras where you can only set the shutter speed to the nearest full stop, there is little or no practical difference. In any case most "inbuilt" meters are not that accurate anyway and are easily "fooled" by light conditions
With hand held meters, it may be slightly different but is still likely to be within a 1/10 stop and well within the lattitude of even E6 film.
Kim
bagdadchild
Established
Look for old cameras in charity shops, flea markets etc.. A couple of years ago, I bought two Yashica Electros in charity shops for about €1 each, both had a perfectly fine mercury battery inside.
lxmike
M2 fan.
I remember when the push to ban mercury batteries was first published, Amateur Photographer published and article on the demise of the 625 mercury cell and a full list of what cameras would be defunct, (there words, loose quote), the list seemed endless, it sent a shiver arround the Uk camera world