Can Hearing Aid Batteries Power Your SLR ?

[DF]

Ever try these to save some $$bucks - instead of the usual (normal) 76 cells? Will they work?

 

[MattKing]

I use 675 hearing aid batteries in an adapter with meters (and in the past cameras) that were designed to use the now no longer made mercury 625 batteries. The zinc air technology in hearing aid batteries provides similar results to those old mercury batteries, but with much shorter life.
If the camera is designed to use silver oxide batteries, the voltage from the hearing aid batteries will be too low.

 

[voceumana]

Hearing aid batteries have a very short working life--in my hearing aids, I get about a week's life in the left ear, and 10 days in the right ear; (my left aid is the controller, so it probably draws a little more current). I'd hate to only get such a short life in a camera battery. I pay about $0.65 per hearing aid battery, so I think you'd end up paying more by using them considering their life.

 

[Dan Fromm]

Hmm. I have a Gossen Lunapro (Lunasix 3 outside of the US) that uses mercury cells. I now use 675 hearing aid cells in it. They last about 2 months before the meter indicates weak battery.

vocehumana, hearing aids draw more current and are turned on much longer than cameras and light meters. I believe that you reported your experience accurately, think it isn't relevant for cameras and light meters.

 

[PhotoJim]

If you want to save some money, most cameras that use MS76 cells will work fine on LR44 alkaline cells, which are very reasonably priced.

 

[Paul Howell]

I use hearing aid batteries in older 60s and 70s vintage bodies, the voltage is closer to old mercury batteries. With a couple of bodies, Petri, I use an adaptor, others 675, like the Miranda EE, 675 fit well. With the camera turned off, maybe a couple of months, in most cases what I do is remove the battery and put the sticky tab back over the side the air vent, batteries last a up to 6 months. In terms of air vents, I had to drill a vent through the back of the metal batter compartment cover on my EE it was so well sealed that the zink air stopped working in a few hours.

 

[wiltw]

Hearing aid batteries permit continued use of some cameras that otherwise require the use of mercuric oxide for meter accuracy. A steady 1.35v from mercury, 1.4v from air cell.

Hearing aid batteries as a substitute for the required battery (silver oxide) has the disadvantage of fundamentall shorter life (while powering the camera electronics) compounded by the continued depletion of the air cells even when the camera is turned off and/or the battery removed from the camera. And the air battery is starting with a lower voltage, about the level of an almost depleted silver oxide cell.

 

[E. von Hoegh]

Ever try these to save some $$bucks - instead of the usual (normal) 76 cells? Will they work?

If you mean s76, no.
They will however do a good job replacing mercuric oxide cells.
S76 is silver oxide chemistry, 1.5v nominal and a flat discharge curve. Mercuric oxide is 1.35v nominal, flat discharge curve; hearing aid (zinc -air, actually an early type of fuel cell & a descendant of the Smee cell)1.4v nominal and a flat discharge curve.
To extend the service life of zinc air cells, block off all but one of the 4 or 5 air holes, I get at least a year out of them this way.
If your camera's meter uses a bridge circuit, use whatever fits, voltage needs only be in the general vicinity. Electronic shutters will need the correct voltage.

 

[DF]

Good thing I kept the receipt - gonna takem back right away.

 

[guangong]

Life was simple when almost all cameras and meters used 625 battery, with few exceptions such as Minox C. Afterwards no common battery used. For most of my older cameras I use adapters such as MR 9. Most more modern cameras and meters use commonly available batteries...but usually out of stock at local Walmart.
What is annoying is while the evil mercury button battery was banned,we were directed to buy the sainted mercury laden fluorescent light bulb.

 

[PhotoJim]

Life was pretty simple in much of the '70s/early '80s too. Almost everything seemed to use the S76/MS76 (or its LR44 twin).

 

[Wallendo]

I have used many hearing aid batteries as replacements. My rule of thumb is to do a reality check when loading the batteries and adjust the camera ISO settings to give what I suspect is the proper exposure (either with a hand-held meter or Sunny 16). I repeat this with each session of use. Some camera/batteries require a 1 or 2 stop adjustment, some require no adjustments. When I have to adjust a used battery, it generally suggests it is time to replace the battery.