What battery to use in a Gossen Luna Pro S or Lunasix 3s?

<p>Hi all,</p>

<p>I just got one of these, and it uses old 1.35v mercury cells, now no longer available.</p>

<p>I read that the only non linear element in the meter is the CDS cell, so that you can use two 1.5v batteries with no problem as long as you calibrated the meter:

<p>Any ideas?</p>

<p>There is no point in calibrating <em>any</em> exposure meter to alkaline cells, as they have seriously unstable voltage as they age. There meter will drift two stops or more as the batteries slowly fade away.<br /> Buy <a href="http://www.bhphotovideo.com/c/product/89868-REG/Gossen_GO_4145_Adapter_Kit_Battery_Holder_for.html">Gossen's adapter</a> for two 357 silver oxide cells (under $40), and you may or may not need to also have the meter recalibrated. I did, that cost me $60 at Sanford Camera Repair. Well worth it, it's a superb meter, and I love the "ergonomics" of it.<br /> Silver oxide cells have very stable voltage, almost as good as mercuric oxide cells.</p>

<p>You can also use Wein cells. They have a discharge curve very similar to the original mercury cells.</p>

<p>- Randy</p>

<p>C.R.I.S., in the Phoenix area, sells an adapter for about $35-40. The Weins are reported to have a short life, and aren't cheap, so the adapter is better in the long run.</p>

<p>I also have a Gossen Lunasix 3 (known as Lunapro in North America).<br>

I can still get the mercury batteries for it and my old Minolta cameras at<br>

camera shows here in Toronto. Try a camera show, someone will be<br>

selling them. Funny, the new 'Green' flourescent light bulbs have more mercury in<br>

them than the camera batteries. But it would be politically incorrect to mention that we<br>

are now forced to buy them!<br>

Best regards,<br>

/Clay</p>

 

<p>I keep hearing that people have experienced short life with the Wein cells, but I've not seen it myself. I get a couple of years out of a pair of these in my Luna Pro...</p>

<p>- Randy</p>

<p>I have a Lunasix 3 and was lucky enough to find the official Gossen battery adapter on the big auction site for a reasonable BIN price. It might be worth checking there from time to time. Before that I used the Wein cells, but of course the standard EPX76 button cells are much cheaper.</p>

<p>John please explain the need for the recalibration AFTER installing the Gossen adapter. What exactly did Sanford do to the meter and why?</p>

<p>The meter was obviously inaccurate with the adapter and appropriate batteries. I didn't test it with Mercury batteries (despite having three in refrigerated storage), so I don't know if it was accurate with them.</p>