Author Topic: SR44 vs LR44?  (Read 1245 times)

SR44 vs LR44?
« on: December 11, 2019, 01:37:42 pm »
These button batteries are the same size and rating so what's the difference?

Obviously chemically SR44s are silver based but do they last that much longer?

Our work venues are recommended to use SR44 batteries but being easier to get hold of we use LR44s. Is it just longevity or could there be more going on? Could they damage a device that recommends Sr44s? I doubt it but someone on here will know more about it.

Re: SR44 vs LR44?
« Reply #1 on: December 11, 2019, 01:39:59 pm »
I switched to SR44 in my Zeiss Ikon camera as they kept working when it got cold. Otherwise, I believe that they are pretty interchangeable.

Obviously, a Leica M4 doesn't need a battery!

Kim

  • Timelord
Re: SR44 vs LR44?
« Reply #2 on: December 11, 2019, 01:45:51 pm »
IIRC silver oxide also has a flatter discharge curve than alkaline - the voltage stays higher for longer, then tails off suddenly.  Whether this matters depends on the device you're using it it.  If it specifies SR cells, it may be fussy about voltage and not able to make full use of the energy available in an alkaline cell.

I don't know if there's a significant difference in self-discharge.  They're all massively better than the zinc-air ones that barakta litters around the place.
Careful, Kim. Your sarcasm's showing...

Re: SR44 vs LR44?
« Reply #3 on: December 11, 2019, 01:47:03 pm »
LR have considerably lower capacity than SR.
"Yes please" said Squirrel "biscuits are our favourite things."

Re: SR44 vs LR44?
« Reply #4 on: December 11, 2019, 06:58:09 pm »
LR have considerably lower capacity than SR.

Normally stated to be between 50-100% more capacity for silver oxide. (I've just been looking into it because the previously cheap silver oxide cells for our stopwatches (I get through about 50 p.a.) have been discontinued, so we would be paying 4x as much)
If it ain't broke, fix it 'til it is...

hellymedic

  • Just do it!
Re: SR44 vs LR44?
« Reply #5 on: December 11, 2019, 07:01:01 pm »
I've had bike computers on silver cells. They did not last long. Others have lasted longer.

Re: SR44 vs LR44?
« Reply #6 on: December 13, 2019, 12:58:38 am »
I've had digital verniers that are meant to run on SR44 cells.  If you use LR44 cells in these calipers, the lower voltage manifests itself by putting the 'low battery' indicator on earlier than normal. Fortunately the thing still actually works when the voltage is far lower than normal, you just have to become accustomed to using it with the indicator flashing at you (for most of the working life of an LR44 cell, and then having no further warning before the thing finally claps out on you.

When I've used SR44 cells, they have seemingly varied considerably in quality/longevity, in a way that I didn't find a meaningful pattern to.

cheers

Kim

  • Timelord
Re: SR44 vs LR44?
« Reply #7 on: December 13, 2019, 11:31:35 am »
I've had bike computers on silver cells. They did not last long. Others have lasted longer.

Most of them seem to use CR2032 lithium cells these days.  Which seems like a better choice, tbh.
Careful, Kim. Your sarcasm's showing...

hellymedic

  • Just do it!
Re: SR44 vs LR44?
« Reply #8 on: December 13, 2019, 01:34:25 pm »
I've had bike computers on silver cells. They did not last long. Others have lasted longer.

Most of them seem to use CR2032 lithium cells these days.  Which seems like a better choice, tbh.

David's are mostly either LR44 or LR43 AFAIK. Mostly VERY basic cheapies.
One is a CR 2032.

Re: SR44 vs LR44?
« Reply #9 on: December 13, 2019, 04:11:11 pm »
My first OZZO bike computer went for about 10 years on the first battery- an LR44 I think.
If it ain't broke, fix it 'til it is...

Kim

  • Timelord
Re: SR44 vs LR44?
« Reply #10 on: December 13, 2019, 04:35:14 pm »
I had an Aldi cheapy that used LR44s, it seemed okay battery-wise, in as much that the original battery outlived the sensor cable.

I think I've got a Cateye somewhere that might use them.  The cable was too short for the bike I wanted to use it on, so it went in the useful box.
Careful, Kim. Your sarcasm's showing...

Re: SR44 vs LR44?
« Reply #11 on: December 16, 2019, 08:04:22 pm »
Quote
They're all massively better than the zinc-air ones that barakta litters around the place.
As a hearing aid user I'm interested in why zinc air is used. S, Saftey? I suspect that if you swallow one it won't injure you*. Lithium can be fatal as the battery fizzes away and acids eat through your gut. And also a flat discharge Voltage.
*No air down there!

Kim

  • Timelord
Re: SR44 vs LR44?
« Reply #12 on: December 16, 2019, 08:58:29 pm »
Quote
They're all massively better than the zinc-air ones that barakta litters around the place.
As a hearing aid user I'm interested in why zinc air is used.

They're cheap and have a surprisingly high energy density, if you don't include the oxygen they absorb from the air.

The main disadvantage is the high self-discharge rate, but that doesn't matter for a hearing aid where the battery is used at a very high duty cycle.  You wouldn't (except in emergencies when there's a hearing aid user around) want to run your bike computer, digital caliper or Lightweight Racing Multimeterâ„¢ on them.


Quote
Lithium can be fatal as the battery fizzes away and acids eat through your gut.

It's more subtle than that, the lithium cell voltage (assuming there's some charge in it) is high enough to electrolyse stomach contents to produce sodium hydroxide at the terminals, which eats through your gut.  Lower voltage cells can't do that.  The danger is that it happens much more quickly than a cell corroding and leaking its contents.


Barakta will be along at some point to share her childhood tales of having batteries confiscated by Stupid Teacher in case she might eat them, and (when slightly older) stabbing the depleted cells with compasses to get the metallic mercury to play with.
Careful, Kim. Your sarcasm's showing...

MikeFromLFE

  • Previously known as Millimole
Re: SR44 vs LR44?
« Reply #13 on: December 17, 2019, 08:18:10 am »


The main disadvantage is the high self-discharge rate, but that doesn't matter for a hearing aid where the battery is used at a very high duty cycle.  You wouldn't (except in emergencies when there's a hearing aid user around) want to run your bike computer, digital caliper or Lightweight Racing Multimeter on them.
 .
Apparently (cough) Zinc Air hearing aid batteries can be a useful stand-in (+/- wads of silver foil) in old film cameras that use weird obsolete battery sizes.
Too many angry people - breathe & relax.