almost exactly in sync with only minor differences in a couple of spots. I think that this can a attributed to some differences in the

The PX625 (also referred to by other names such as PX13) is a small button-shaped 1.35volt mercury battery which great number of camera models were designed to use. Also, one of the sources I found said straight out that the "CRIS" adapters just used a series resistor to drop the voltage. But it's possible that the Small Battery Company does it differently.)Voltage - the voltage of the mercuric oxide cell was 1.35v, the voltage of many of the popular alternatives is 1.5v or so

oxide cell to the 1.35 Volts that your camera was designed for. No adjustment or modification to your camera is required. The Another PX625 replacement is a zinc air battery. The WeinCELL MRB625 is a custom zinc/air battery designed to replace banned The following is a very economical way to power these cameras at 1.4 volts, close enough to the original spec to give good meter readings. Make your self a little sausage of blu-tak, plasticine or in my case play doh (I have a 2 year old, this stuff come to hand easily) and wrap it round the very edge of the battery making sure it doesn’t intrude on the flat [+] end. Then simply place it in the battery cap.The LR9 is the least expensive PX625 replacement. They fit perfectly but, as with all alkaline cells the voltage is Some cameras use a (Wheatstone?) "bridge" circuit and the metering doesn't depend on the battery putting out an exact voltage. Cameras where metering means centering a needle on a short + | - scale (or the LED equivalent), are likely to fall into this category and should work fine with alkaline, silver, zinc-air or NiMH substitutes. Uwe, is the Contarex Super meter like this? Some old cameras and meters (e.g. Nikkormat FTN, Canon Cannonet QL17 iii, Gossen Lunasix 3, Pentax Spotmatic F) used the 625 mercuric oxide cell. Batteries based on this technology are now illegal in many countries and often a replacement is needed. The PX625 Battery Adapter allows you to use a modern PR44 675 Blue Tab Zinc Air battery in cameras that require a MR9, 625A, MRB625, PX625, EPX625, PX13, mercury battery. The PR44 675 Blue Tab Zinc Air battery is rated 1.45v and provides a very stable 1.35V output, which is the same voltage as the original mercury battery. This ensures that your camera’s light meter will function properly. I have previously written about adapting a 675 hearing aid battery for use in cameras that require a 1.35 volt PX625. I was pretty confident at the time that since hearing aid batteries operate at 1.4v that this was the solution to this problem… I have since found out that actually, this solution is not always quite as ideal as I had originally thought.

Discharge characteristics - the voltage of the mercuric oxide cell was fairly constant until it was fully discharged, whereas some cells (in particular alkaline) have a voltage that decreases steadily with time cost difference between the solutions. It is close enough that each person will have to make up their Many cameras and light meters were designed for and require a 625 mercury cell: list of cameras and list of exposure meters. Some cameras and exposure meters were designed for 625 sized cells but include voltage regulation circuitry and thus do not require a PX625 to function properly ( list of devices), and so can use the higher-voltage (and less voltage-stable) alkaline (PX625A, 1.5v) or Silver-Oxide (S625PX, 1.55v) cells. Devices without regulation circuitry (or some method of compensating for other voltages) can use Zinc-Air type cells made especially - with the correct 1.35v potential - to replace the mercury cells. Zinc air hearing aid batteries have a flat discharge curve and a lower voltage of 1.4v -1.45v. Therefore it is possible to use these with the adapter above as a replacement for the 625. The downside is that zinc air have a relatively short lifetime of around a month, and can discharge blue goo when then are used up. And finally, the moment of truth… The MR-9 battery adapter giving the Leica MR-4 the correct voltage.Zinc-air: usually seems to work well but on some cameras, in some lighting conditions, the difference between the 1.35V assumed and the c. 1.4V delivered can put the exposure off by as much as a stop. I've been reading up on this and it seems to depend very much on the model of camera how well the various substitutes work. For instance: The MR-9 adapter uses a Zener diode to reduce the voltage, if I am not mistaken. The electronics actually require a minimal current drain to function properly. See here: In the following 3 photos you can see the MR-9 battery adapter on the left, with a modern PX625 on the right. Positive side faced up Negative side faced up with the MR-9 battery adapter empty Negative side faced up with the MR-9 battery adapter with 386 battery slotted in

NiMH rechargeable: 1.2V: may not even be possible to calibrate the meter for this voltage, and if you do it will be way off if you run out of charged--up batteries. oxide cells to the 2.70 Volts that yourlight meter or camera was designed for. No adjustment or modification to your Another mercury PX625 replacement is a zinc air battery. The WeinCELL MRB625 is a custom zinc/air battery designed to replace banned Silver cell with voltage-reducing adapter: the adapters don't contain actual voltage regulators but just a resistor that will reduce the voltage to approximately 1.35V when the current drawn is that of a typical meter circuit. So they'll work perfectly with some cameras in most or all lighting, but not very well with cameras that draw more or less current than the designer expected, or whose current draw changes significantly with the light level. Minolta you can adjust the film speed ring by 1/3 of a stop. By understanding how the battery functions in your camera,

Similar Products

Other meters were designed with the constant 1.35V of a mercury cell as a fundamental assumption. In this case using any other type of cell can cause problems. But different problems with different cameras because of the way the meter is affected by the characteristics of the cell. Alkaline batteries have an unpredictable drop off in voltage over their life - they start off at 1.5v, but will end up well below 1.35v. Because of the bridge circuit the spotty should be better placed to deal with this than other brands, but I'm not sure if it can compensate for low voltage (others may be able to confirm). The LR625 is cheap and almost in the same size as the LR625. The only problem is that the voltage of LR625 is 1.5v, which is 0.15v higher than that of the PX625. The difference in voltage may slightly affect the light meter. But in reality, it does not matter much. I thought the best solution would be easy to come by. The original PX625 mercury batteries that these camera used from The mercury oxide battery problem, at Konica SLR system, providing information about the PX625 and PX675 battery that is not specific to Konica models