I bought this Caliper and.........

Got a 357 battery and it seems to work OK. The innerds were embossed with a 1967 date, does that seem right? At any rate, I think this caliper will work fine for me and be dedicated to the PM25.
 
The 357, LR44 and SR44 batteries all have the same form factor and output voltage. The LR44 and 357 use lithium ion chemistry. The SR44 uses silver oxide chemistry, and will last significantly longer. But any one of the above will work very well.

I learned about these just recently when I was about to buy a Mitutoyo digital caliper and decided to investigate how to identify counterfeits. I'm absolutely confident the one I bought from Travers via Amazon is the genuine article.
 
hman said:
The 357, LR44 and SR44 batteries all have the same form factor and output voltage. The LR44 and 357 use lithium ion chemistry. The SR44 uses silver oxide chemistry, and will last significantly longer. But any one of the above will work very well.

I learned about these just recently when I was about to buy a Mitutoyo digital caliper and decided to investigate how to identify counterfeits. I'm absolutely confident the one I bought from Travers via Amazon is the genuine article.
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The 357 and SR44 batteries are silver oxide batteries and have been around since the 1970's, long before the invention of the lithium ion battery

The LR44 is an alkaline manganese battery. Back in the 1970's button cells were typically mercury oxide cells and Ray O Vac, for whom I worked as an analytical chemist had a manufacturing facility in Portage, Wisconsin which exclusively made mercury oxide batteries. In the mid '70';s, mercury became a hot environmental issue and mercury oxide cell production ceased. Alkaline manganese batteries were just coming on line and the alkaline manganese button cell was developed as a less expensive replacement for the mercury oxide cells.

All of these battery types contain alkaline electrolyte and will leak, given the opportunity. Leakage usually occurs near the end of life of the battery where the reaction products have a lower density and therefore higher volume than the initial products. The case will swell and eventually the seal ruptures and electrolyte leaks out.

Leakage will most often occur with equipment which hasn't been used for some time. This is more a problem in equipment which is "always on" like some of the import calipers. Those calipers that retain their zero are an example. When I find leakage in a piece of equipment, I remove as much of the solid material as I can and then follow with multiple rinses of clean water. A cotton swab is useful for controlled rinsing. A final rinse with 90 -99% isopropyl alcohol will help to remove any remaining traces of water.

The alkaline electrolyte will remove the nickle plating on the battery contacts so I will remove any oxidation with an abrasive. In worst cases, the electrolyte will wick up into the electronics, causing a malfunction due to shorting. I had this happen on several occasions and it required disassembly and a more thorough cleaning to restore function.
 
Fun fact. Back in the 60's and 70's, Ray O Vac had a leakage guarantee that would replace any piece of equipment damaged by battery leakage with new equivalent equipment. Back then, most batteries were zinc carbon, aka Leclanché, cells. The zinc cathode was actually the outer shell and was consumed during use, giving rise to a high probability of leakage. Roy O Vac developed a steel case to contain the leaked and marketing coined the phrase "sealed in steel". Working in the lab, we would get these pieces of equipment back for determination of cause of failure and subsequent warranty replacement. The greatest use by far was for flashlight so this wasn't a big hit. However, transistor radios were just coming into use and replacement practices were beginning to become a fairly large expense. On the plus side, the damaged products were discarded and we were free to take them home and clean them up,, restoring full function. One of the perks.
 
Wow! Many thanks, RJSakowski ! It's always great to get the real story from somebody who knows what he's talking about. As I'd mentioned, my info came from investigating real (with SR44) vs fake (with LR44) Mit calipers. I'm happily surprised to hear that the 357 is silver oxide. Those were the ones they kept in the office supplies at Hewlett-Packard, for replacements in calculators.

PS - another !!@&^%##!! effect of swelling/leaking alkaline batteries, with NO easy cleanup/repair, was when cells would misbehave inside a Maglite flashlight. Between the close clearance in the flashlight barrel and the reaction of the aluminum to the alkaline leakage, getting the battery out was nearly impossible. I used to keep a flashlight in the glove box of my car "for emergencies." It would be there, pretty much ignored year round and subject to all kinds of nasty temperature swings. Lost a couple of nice Maglites that way. :(
 
hman said:
Wow! Many thanks, RJSakowski ! It's always great to get the real story from somebody who knows what he's talking about. As I'd mentioned, my info came from investigating real (with SR44) vs fake (with LR44) Mit calipers. I'm happily surprised to hear that the 357 is silver oxide. Those were the ones they kept in the office supplies at Hewlett-Packard, for replacements in calculators.

PS - another !!@&^%##!! effect of swelling/leaking alkaline batteries, with NO easy cleanup/repair, was when cells would misbehave inside a Maglite flashlight. Between the close clearance in the flashlight barrel and the reaction of the aluminum to the alkaline leakage, getting the battery out was nearly impossible. I used to keep a flashlight in the glove box of my car "for emergencies." It would be there, pretty much ignored year round and subject to all kinds of nasty temperature swings. Lost a couple of nice Maglites that way. :(
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I did a comparative analysis of the button cells used in calculators and the 357 gave the best bang for the buck. This was largely due to the flat discharge curve compared to the alkaline manganese batteries.
Leaking alkaline cells in aluminum flashlights is a killer. The aluminum case reacts readily with the electrolyte, the swelling in the process solid,ly locks the batteries in the case. The safest approach would be to remove the batteries from your emergency light and store them in a plastic container until needed.
 
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RJ, have you done any comparisons of the EPX76 vs 357? One of my tools came with a EPX76. Never heard of it before, I looked at the data sheet & it seems to have a longer discharge curve but I assume at the expense of something else? I probably wouldn't notice a difference anyway but just curious.

I mainly use 357, they last very long for me in my measuring tools & are cheap but if the EPX76 is better bang for the buck I might try some. I have not looked up prices though.
 
darkzero said:
RJ, have you done any comparisons of the EPX76 vs 357? One of my tools came with a EPX76. Never heard of it before, I looked at the data sheet & it seems to have a longer discharge curve but I assume at the expense of something else? I probably wouldn't notice a difference anyway but just curious.

I mainly use 357, they last very long for me in my measuring tools & are cheap but if the EPX76 is better bang for the buck I might try some. I have not looked up prices though.
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Based on Union Carbide's spec sheets, it appears that the EPX76 has a slight advantage over the the 357 (~10%).
 
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