Zinc Air batteries?

cobb

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I use to have a talking watch that used 4 mercury cells that were hearing aid batteries. Since they banned them a few years ago I was told to use zinc air batteries. Well, they worked for a day then fizzled out. I ended up having to revert to silver oxidide ones that were 2 bucks each.

Since I have seen some larger zinc air batteries under the make of fuel cell that is suppose to allow you to charge your pda or cell phone 3-4 times before it expires.

I was wondering if zinc air would be any better for powering lights? THis way you can have a use for the air flow if you made a hot light that needed air cooling and it could also help power it.

Just wondering...
 

LED_ASAP

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Zn-air cannot be used in watches if they are air-tight. You will need fresh air to enter the cell in order to react with zinc and generate electricity.

Zn-air is also rated for very low current draw. You may be able to power a few Nichia LEDs for a long time, but you won't be able to use it to run high-power flashlights.
 

MikeLip

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Zinc-air is not a good choice for anything other than hearing aids. As soon as you pull the tab, not only do the cells "turn on", they also start to die, even with no load on them. Even if you kept your current draw to something reasonable, they wouldn't last for more than a few weeks before they simply expired. Think of it as a self-discharge along the lines of a Ni-Cad battery, only much faster and irreversible.

Alkaline is a much better choice for something that will be used intermittently, like a flashlight. Zinc-air is great for low current draw allpications where the device is in use continuously or almost so, like hearing aids. I wear aids and they are in my ears 18 hours a day, and zinc-air is a godsend - I used to have to replace batteries every day, but zinc-air runs the aids for days. But for lights? Nah.

Mike
 

hank

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Try a search for "camera repair" plus "mercury battery" with Google -- this has been an issue for a while, and there's quite a variety of different approaches. One might work for your application.
 

carbonsparky

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There are some places on line that sell silver oxide batteries in quantity for very reasonable prices. I have been buying my SR44s from this place.
http://www.sr44.com/payment.html

It has been awhile since I have ordered any, but their sight is still there.
There are other places with similar prices, just Google your battery part #.
 

MikeLip

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[ QUOTE ]
Zelandeth said:
It has been done. Here's a link to a review on the LED Museum of a light called the FireFli, using four #10 Zinc Air cells.

LED Museum Review: FireFli

And yes, finding that page took a while...knew it was in there somewhere though!

[/ QUOTE ]

I saw that review a while ago - very neat idea! It takes some extraordinary sealing to make a zinc-air light work since it takes very little air to light off the battery, and it strikes me that it's more cool than anything else. If your o-rinds dry out, you're outta luck, so you have to amintain the seal if you want to be able to rely on having light. I'm gonna have to get one of those and play with it.

Mike
 

milkyspit

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I bought a bunch of zinc-air hearing aid batteries at the local drugstore a couple months back because they'd marked them way down in price. (Hope they're not expired! /ubbthreads/images/graemlins/icon15.gif I'll check at home later.) Seems to me these coupled with an LED operating around 1mA in regulation would make a nice portable nightlight... just load it up, let it run 24/7 until the light goes out, then replace the cells! Does this make sense?
 

PeLu

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Willie Hunt of SF and LVR fame uses big Zinc-air cells a lot for his caving lights and is very pleased with them.
They are about cigarette box sized IIRC.
It is possible to close the ventilation hole again for longer storage.
 

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