Replacement battery

For those needing a replacement for the 1.35v PX625 and PX13 mercury batteries, WEIN Products makes one.

Their MRB625 is a Zinc/Air dropin replacement. I had to get one for my Canon TX camera.

So far, so good.

The Wein cell works well, but the charge diminishes much more quickly in the Zinc-Air than the PX-13 batteries.

There are many posts on-line for substituting various longer-lasting batteries with an adapter ring, that are good.

 

A good site, but there are many more, is Oleson's at

Cheap Easy Mercury Battery Replacement

 

There are sites for adapting silver cells, too

Here's another approach:

 

LINK ----- Modifying a PX625 Battery to Take a Standard AG13/SR44 Cell

I use the CRIS Camera adapters. They work great in my older Nikons and Nikkormats.

I simply use the PX625a (alkaline battery with exact same dimensions as the PX625 mercury battery) in my Canonet QL17 and Canon EF and they work fine.

I read a web site that provided excellent info about replacements (source: PX625, PX13 or MR9. Replacements for these discontinued Mercury cells.), where I chose to use WeinCELL MRB625 batteries in my Canon FTb cameras. They stated that alkaline batteries do not provide a steady 1.35V...instead it slowly decreases it voltage throughout its lifetime. I imagine the FTb camera could handle the voltage variation--but rather not risk it long term.

I have an alkaline battery in an FTb.

 

I am not so sure what you mean by risk.

It might give the wrong meter reading, usually a little, possibly a lot.

 

I have tried comparing my FTb against sunny 16, but then I don' t know how sunny it was.

In any case, it was close enough for black and white film.

 

I have an FE2 that is supposed to use alkaline or silver oxide or lithium batteries,

who's meter is somewhat off. As well as I know, the offset is constant, and so I set

the exposure offset appropriately. So, I don't worry so much if others are a little off.

 

There is risk of wrong exposure, especially if you use slide film.

Use an external meter once in a while to see how far off it is.

The risk I was referencing to is from an electronics perspective. For example, if the native electronics is rated for range of voltages that includes 1.5V, the electronics will not "burn up" with the higher voltage or degrade over time from high voltage abuse. The user's manual clearly states 1.35V battery should be used for it's constant level of voltage. I cannot locate any other information about the electronics of the Canon FTb and its specifications. I do not have access to the service manual...so I do know what it states about the meter's electronics specification. So my risk is cautionary--would hate to blow/overload a resistor or capacitor in the camera that destroys the meter's functionality.