Lithium vs alkaline

[ERamos]

Excuse my ignorance, but can anybody here tell me the difference between alkaline batteries and lithium ones?, the reason I ask is that I have some old equipment that run on mercury batteries that no longer exist, the replacement is an alkaline battery that I can get from the internet only, on the other hand, I can easily find a lithium battery that I can make fit with almost no effort, but I'm concerned about causing damage to my stuff.

Any comment will be appreciated.

ERamos

[RossW]

If the voltage is the same (or very close) it shouldn't cause harm. Lithium ion batteries will drain at a much slower rate than alkalines, although depending on your use it may not really matter. Every so often someone puts a link to a good battery type comparison article on the web on these forums... try a search. Limit your search to somthing less generic than "battery" however, or you'll get tons of less-than-useful hits. For example, I'm pretty sure a search on "NiMH" will bring up one of those comparison links, as the question was probably posed about nickel batteries vs. alkalines.

[DavidW]

If you're talking about 'button cell' like batteries, the Lithium cells are typically 3V - way more than I expect the mercury battery to be. Check the voltage and polarity instead of just fitting the cell and regretting it.



David

[benhasajeep]

As said above as long as the voltages and shape / connections are the same. You will be just fine. Mercury / alkaline / lithium is just the inside materials. Connections and voltages are the big concerns!

[SkipD]

the reason I ask is that I have some old equipment that run on mercury batteries that no longer existWhat type of equipment are you referring to? Mercury batteries were used in light meters in the olden days because the mercury batteries had an extremely flat (constant) voltage curve over a very large percentage of their life. This meant that circuits could be built that essentially used the voltage from the battery as a calibrated reference.

There are no batteries today that really perform the same as the old mercury batteries. By that, I mean with a constant voltage and a rather long life. Wein has an "zinc-air" battery technology that performs in a similar manner to the mercury batteries as far as the constant voltage is concerned, but for a MUCH shorter life span and a much higher cost than the old mercury batteries. Here's a link to Wein's web site for their batteries: http://www.omegasatter.com/v2/products/displaycategory.cfm?CatID=651

If you are trying to use an old light meter, I would highly recommend considering shelving it and getting a more modern meter.

Additional info - the Wein cells come sealed against air intrusion and are relatively inert at that point. Once you open the seal to use the battery, the clock is ticking on its demise. You cannot stop the clock on the battery's death, either.

[Wilt]

>>the reason I ask is that I have some old equipment that run on mercury batteries that no longer exist, the replacement is an alkaline battery that I can get from the internet only<<

As has been mentioned, the Wein air-zinc cells do provide a constant voltage about the same as mercuric oxice cells...about 1.35v. Their problem is not only cost, but the fact that once activitated, the cell life is a fixed TIME period even if the camera is not in use.

Do NOT use batteries that start life at 1.5v and decline progressively during their lifetime. Almost all circuits designed for mercuric oxide are VOLTAGE SENSITIVE, and light meters will give an erroneous reading until they have dropped down to the relative short period where they have declined to 1.35v!

[ERamos]

Thank you very much for your quick responses.

I'm using this battery in a very old Yashica Camera, it has a very high sentimental value, that is why I'm struggling to keep it working.
All your information is very helpful, thanks again.

ERamos

[SkipD]

Thank you very much for your quick responses.

I'm using this battery in a very old Yashica Camera, it has a very high sentimental value, that is why I'm struggling to keep it working.
All your information is very helpful, thanks again.

ERamosI presume the mercury cell was for a metering circuit. They were never, to my knowledge, used for anything that drew any significant current. The Wein cell is the only solution that is worth using, as any other solution will not provide the accurate and stable voltage source (1.35 volts) that your meter circuit probably needs to work properly.

[Jon]

Criscam (http://criscam.com/) makes adapters to allow use of silver oxide button cells in cameras designed for mercury buttons, adjusting the voltage as part of the process. Lithiums are too high voltage.