Zinc/air batteries

[Satch]

One of my antique bits of kit requires small battery to keep memory alive, but these are the now forbidden 1.35v Mercury batteries.

Told there are alternatives in the form of Zinc/Air batteries which seem quite costly but have the same output and are stable, unlike some of the small Lithium cells which tend to be 1.5v. But they may only last 3 months!

Anybody know how long these last in real life? Feeling a bit hard done by as the old Mercury cells have lasted 12 years.

 

[grober]

Silver oxide converter

They dont last very long at all . Had the same problem with my Olympus om1 camera which used the 1.35 Mercury cell. there is a wee device which employs the longer lasting 1.6v silver oxide cell but drops the voltage via schottky diode to 1.35v. Problem described here http://www.johndesq.com/pinhole/manual/battadapt.pdf and adapter available here http://www.smallbattery.company.org.uk/index.htm?http://www.smallbattery.company.org.uk/sbc_mr9_adapter.htm

 

[BTB 500]

I'd have thought a 1.5V alkaline cell would be fine, Maplin sell one for £1.99 specifically as a PX625 Mercury replacement (V625 Alkaline).

www.maplin.co.uk

 

[big x]

I'd have thought a 1.5V alkaline cell would be fine, Maplin sell one for £1.99 specifically as a PX625 Mercury replacement (V625 Alkaline).

www.maplin.co.uk

The problem is the slightly higher voltage causes things like old camera exposure meters to underexpose.
Zinc air batteries for hearing aids once exposed to the air seem to last about 5 minutes so the only solution is the step down methods, buy a new camera or use exposure compensation.EG. I have a Braun Nizo super 8 camera that I use on documentaries and it just requires +1.5 stop if using alkalines.

adam

 

[BTB 500]

The problem is the slightly higher voltage causes things like old camera exposure meters to underexpose.

I understand that, but it didn't sound like this was for a camera.

 

[Satch]

I understand that, but it didn't sound like this was for a camera.

No but damn useful link in general as I actually have an Olympus OM1-n that has been sitting around for ages. Battery must be long gone.

 

[BTB 500]

I had an OM-1n and an XA rangefinder compact ... lovely cameras