Replacement PX675 - what voltage should it read on meter?

[smudwhisk]

:bang: OK, this may sound stupid I know but what voltage should a Wein-replacement PX675 read on a digital test meter please? Should it be 1.35v or the 0.5v it's showing currently? Tried it on my Dad's digital test meter today and it showed 0.5v, but a normal AAA 1.5 battery read 1.7v (as he said he would expect as it's new). Now when Jessops in Brum tested it and also tested a Wein-replacement PX625 which they took straight off the shelf, both tested about the same but not very high. Does this type of battery not register as high as you would expect on a battery test meter? The reason I ask is that the Konica C35 Auto (which I acquired last week) has had its wires re-soldered on to the terminals for the battery and I still cannot get any movement out of the light meter. Interestingly the original mercury battery that came with it registered about the same voltage on the digital test meter. If the batteries are OK, then the camera is still not working correctly and as I'm fast running out of time to return it, I'm er'ing in that direction. Any suggestions appreciated. :bang:

 

[ChrisN]

0.5v is definitely not good. I use the 1.4v hearing-aid batteries, and they measure very close to 1.4v. Send it back.

 

[JonB]

Volts are volts, regardless of where they come from, and 0.5v on a 1.4v battery indicates rigor mortis. With a zinc-air battery, however, it takes 15-20 minutes (estimate) to get up to full power, so pulling one off the shelf and measuring it immediately won't be terribly meaningful.

I'd drop a cheap alkaline battery in there. It won't be accurate, but if the meter doesn't do anything, your can blame the camera doubt-free.

 

[Kat]

On a side note, is the .05 voltage difference negligible in meter readings with zinc air cells, or should adjustments still be made?

 

[Kim Coxon]

There are a couple of things to consider. The meter reading will depend to some extent on the meter and the load on the battery which comes down to internal and external resistances. The chemistry of the wein cell/ hearing aid battery is exactly the same as the mercurey batteries. The only difference is that in a mercury battery, they added mercuric oxide which decomposed to give the oxygen needed for the battery to work. In the other cells, this oxygen is provided by the air hence the need for holes and the wait for the battery to "come on line" once the holes are uncovered. Without that air the cell will not produce any proper current.

Kim

On a side note, is the .05 voltage difference negligible in meter readings with zinc air cells, or should adjustments still be made?

 

[Trius]

.05 is very negligible voltage, and it seems unlikely there would be two bad/flat batteries in your possesion. Check to make sure that your probes are contacting the anode and cathode properly. with the different shape of the PX675, that might be a problem. You might also try a zinc-air hearing aid battery as a third test battery.

Earl

 

[smudwhisk]

Tested the battery today after it had been out of the packet and minus the green seal, and it tested 1.35v so obviously although left it 30+ minutes yesterday it wasn't long enough. I couldn't find a 1.4v hearing aid battery (not sure who will sell them) but did pickup a brand new 1.35v mercury! It states made in W Germany and it tests a full voltage. Tried it in the C35 auto, light meter still not working! Oh well, looks like it's being returned, at least now I've a supply of PX675 or equivalent for future use! Thanks for all suggestions. 😀

 

[Kat]

Thanks for the replies, too!🙂

 

[ClaremontPhoto]

http://www.smallbattery.company.org.uk/ will have the info somewhere.