Just an FYI: 4LR44 not the same as A544 battery for Mamiya 7II

<p>When I replaced Mamiya 7II with a Duracell A544, which indicates that it is the equivalent of 4LR44, the camara ceased to function. As I was shooting with light snow falling, I thought I fried Mamiya's electronics.<br>

I was about to send the camera to Mamiya for repairs, I fortunately found a spare 4LR44 battery at home.<br>

Replaced the battery with this one ---- wala it worked.<br>

Just an fyi for folks using Mamiya cameras requiring 4LR44.</p>

<p>You might want to check both batteries with a digital volt meter. My guess is the A544 is below spec.</p>

<p>Wikipedia info if correct ...<br /><a href="http://en.wikipedia.org/wiki/List_of_battery_sizes">http://en.wikipedia.org/wiki/List_of_battery_sizes</a><br />4SR44 - PX28A - A544 - K28A - V34PX - 4LR44<br />"S" version = 170-200 mAh @ 6.5V<br />"L" version = 110-150mAh @ 6.2V<br />People in the know, are there two distinct types ... S and L ?<br />Or do they mean silver oxide being = S and alkaline being = L?<br />It would then be that the S version has more current capability and a higher voltage too. As the temperatures dropped and battery potential rolled off, that may have been the mitigating factor.</p>

<p>Jim</p>

<p>For what it's worth I have a Bronica EC that seems to work slightly more reliably with the silver oxide version of that battery. It just seems to have more kick for more shots. </p>

<p>There is now a nice Lithium variant that solves most problems. Silver and alkaline types, as above, are fine.</p>

<p>Bronica has recommendations on line that rank batteries as Silver Oxide best, Lithium worst with alkaline in between. In the explanation it sounds as though some lithium batteries might be OK, but the various makes apparently vary a lot in their capacity. Some of that is apparently related to making trade-offs between transient current output and shelf life.</p>

<p>http://www.tamron-usa.com/bronica/batteries.asp</p>

<p>DaveT (SQ-A owner)</p>

<p>This is a very belated response, but hopefully might help some folks out. Several years ago I had to replace my Mamiya 7 II battery, and the camera then ceased to work with the new batteries. Fortunately I was living in Tokyo at the time so took it to their repair center.<br>

This was an issue that they were very familiar with, and despite the language problems they fixed it almost instantly. They simply replaced the battery cover, and the camera has worked great ever since. I believe there are some minor differences between supposedly equivalent batteries and the latest battery cover design is required to handle all the variants. The replacement battery cover was silver versus the original black, but it has never bothered me, functionality is more important.</p>

<p>For what it's worth, an Energizer A544 battery, which is billed as a replacement for 4LR44, did not work in my Mamiya 7II. Nor did a couple of CR1/3N batteries that Radio Shack sold me.<br>

In the end, the only battery I was successful in using was a Radio Shack PX28A. I think there may be a very small but critical difference in the size of the batteries, as suggested by Geoffrey Williams.</p>

<p>I wonder if lining the battery cover with tin foil would do the trick. I'm having the same problem as others with an Energizer A544. Will look for the Radio Shack battery. Thanks for all the info folks, this really stumped me last night at midnight.</p>

<p>Answer is yes. Just folded over a small piece of tin foil and placed it in the battery cover, screwed the cover back on, and the A544 battery works fine. Hopefully this workaround helps when needed.</p>