Relpacing mercury batteries in older equiment

[Yeeski]

The 675 zinc-air hearing aid batteries work fine in my F-1n. I ran some Kodachrome 25 last year with no exposure problems. Be aware that, once you remove the tape from a zinc-air battery, it takes a while for it to reach full voltage, perhaps an hour or so.

[benjiboy]

This company in the UK sell a cheap solution to the problem that allows you to use hearing aid batteries with a purpose machined adaptor.
http://www.paulbg.com/px625uk.html

[Steve Smith]

On the other hand on my Canon EF, the meter won't read at all with 1.5v cells.

Probably a silly question and I apologise in advance for its patronising quality!

Did you put the 1.5v cell in the right way round? If you look at the cells, the logical way to insert an alkaline or silver cell is actually the wrong way round. The large part (end and sides) of a modern cell is the positive connection. This would be negative on a mercury cell.

That is way they usually need some tape or a rubber 'O' ring to insulate the sides (apart from making it a comfortable fit).


Steve.

[benjiboy]

Probably a silly question and I apologise in advance for its patronising quality!

Did you put the 1.5v cell in the right way round? If you look at the cells, the logical way to insert an alkaline or silver cell is actually the wrong way round. The large part (end and sides) of a modern cell is the positive connection. This would be negative on a mercury cell.

That is way they usually need some tape or a rubber 'O' ring to insulate the sides (apart from making it a comfortable fit).


Steve.

Rubber "O" rings won't work with the Canon EF Steve because the batteries in that particular camera need to make electrical contact all the way round, and. need to be of a conductive material like Copper.

[benjiboy]

If I have any of these mercury alternative batteries in my camera I check it against a Kodak grey card, with a meter of known accuracy and adjust the I.S.O. to match before I take it out to shoot, because the battery discharge characteristics change over time.

[Steve Smith]

Rubber "O" rings won't work with the Canon EF Steve because the batteries in that particular camera need to make electrical contact all the way round, and. need to be of a conductive material like Copper.

So is the only option for the Canon, a machined adaptor?

I remember when my father put a silver cell in his Spotmatic, the meter moved the wrong way. Then we realised the polarity difference with the cells.


Steve.

[benjiboy]

So is the only option for the Canon, a machined adaptor?

I remember when my father put a silver cell in his Spotmatic, the meter moved the wrong way. Then we realised the polarity difference with the cells.


Steve.

For most cameras like the Spotmatic or the Canon FTb you could use a rubber "O" ring and with the EF Steve you could use a circle of copper wire of the right gauge around each battery to make electrical contact I suppose, but I'm going to send for machined ones that I put a link to in my previous post it's a cheap elegant solution, and you can get the hearing aid batteries anywhere.

[Kiron Kid]

Have your rigs converted-adjusted for Silver Oxide batteries. They're cheap, reliable and readily available.

Kiron Kid