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What's wrong with PX625 batteries?

Jim Gerdy , Dec 17, 1998; 02:45 p.m.

I just bought an old used Luna Pro that takes the Mercury PX 625 cell and it seems to work (compared to my other meters). I still have time to trade it in for a new one and I'm wondering if I should. I have heard that the old batteries are unreliable and hard to find. The store in Chicago where I bought the meter carries them for $5 each (and they say 1.35V on the battery). Am I missing something?

Does anyone know if a newer Luna Pro would perform better because of the battery?


Y. Dobon , Dec 17, 1998; 03:02 p.m.

What's wrong with PX625 batteries?

They were made with mercury and their disposal is particularly nasty to the environment, that's all. Functionally, there's nothing inherently wrong with them.

Gary Watson , Dec 17, 1998; 03:13 p.m.

The real hitch isn't the meter, rather the correct battery and their future availability. They're getting very scarce in the U.S. thanks to an outright ban on domestic production and(further)imports. They can still be found in serious camera shops here in Toronto but rarely elsewhere. The PX625 was great mainly for its long life and very flat discharge curve, making it perfect for handheld and in-camera meters. The voltage matters since it's crucial to accurate metering. For you(and assuming the Luna Pro works properly), the best bet might be $30 for an adapter that drops the voltage of readily available 1.5v cells(www.criscam.com).If the numbers just don't work, it might be wise to get a meter that swallows current(no pun intended)batteries. Aside from their features, Sekonics are wonderful since many of them run off plain 'ol AAs.

Omar Durant , Dec 17, 1998; 04:12 p.m.

I also own an older Luna Pro that originally used mercury batteries. The Gossen company, which makes Luna Pro meters, makes an adapter for the older meters that retails for $18.00. I purchased an adapter through my local camera store about a year ago. It came quickly and consists of an adapter which holds two batteries, also supplied in the order, and it fits perfectly. You will need to recalibrate your meter (match it up with another that is *right on*) and then you will be fine.

Bill Davis , Dec 17, 1998; 05:58 p.m.

There is a clever solution for the mercury battery problem that is offered by C.R.I.S. Camera Services in Arizona (url: http://www.criscam.com/). This is an the MR-9 adapter which contains microcircuitry that converts the output of a Silver 76 battery to 1.35 V, and gives it the sharp cutoff in current that characterizes mercury batteries as they age. It fits right into the mercury battery compartment.

P.S. I have no connection with this company; I've only used the product.

Michael B , Nov 13, 1999; 02:33 a.m.

Search the internet for a few minutes, and you will find a lot of places you can dispose/recycle mercury batteries for a few cents each.

john waugh , Feb 25, 2004; 01:03 p.m.

PX625 batteries

this is a very old search string, but just in case someone comes across it like i did and still needs the info: go to google! there are a number of replacements [like silver oxide and zinc] that deliver the same voltage as the px625 [1.35v] with similarly reliable performance over the long haul. these replacements cost much less than the adaptors mentioned above.

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