M5 battery question

C

Cindy Flood

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I just received an M5 from another RFF member. It joins my M8 and M3 so I am familiar with M's, just not the M5 battery issue. It was recently CLA'd in the Netherlands. It did not come with a battery and the seller has told me to order the WeinCell MRB625 Zinc/Air batteries (PX625 replacement). The firm that did the CLA has written me that I should buy a Mercury battery adapter. I have read through the archives and am still not sure how to proceed. My plan is to get the WeinCell and then use my Sekonic meter to check the exposure. If the low light and high light exposures seem on, I will be OK with the Wein. If not, I think I will send it to DAG. Is this all correct?
 
Assuming the weincell is the right physical dimensions, it will fit and be close enough to the original mercury battery voltage (1.35v I believe) to give a usable meter reading. The adapter takes a smaller 1.5v battery and puts it into a case that also has a little bit of circuitry to reduce the voltage to the correct level. So - either of these two approaches should work.

And as you surmise, the best approach might be to have the camera modified so that you can use the much cheaper PX625A batteries directly in the camera without adapters. Sherry Krauter did mine last year and the meter is now perfect.

And I forgot to add - congratulations on the new camera! The M5 is very different from the other Ms, but very nice to use.
 
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Mine worked fine on the 1.35v Wein cell. However, I sent it in to Sherry about a month ago and she adjusted mine to the PX625A (I believe 1.5v) batteries as well.

The meter on the M5 is a pleasure to use as you have a good idea of the metering area (see the manual for the details).
 
Cindy Flood said:
I just received an M5 from another RFF member. It joins my M8 and M3 so I am familiar with M's, just not the M5 battery issue. It was recently CLA'd in the Netherlands. It did not come with a battery and the seller has told me to order the WeinCell MRB625 Zinc/Air batteries (PX625 replacement). The firm that did the CLA has written me that I should buy a Mercury battery adapter. I have read through the archives and am still not sure how to proceed. My plan is to get the WeinCell and then use my Sekonic meter to check the exposure. If the low light and high light exposures seem on, I will be OK with the Wein. If not, I think I will send it to DAG. Is this all correct?
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WeinCell should work and an adapter should too. Just keep in mind that adapters are very expensive but are very easy to do at home just by soldering a Schottky diode in seris with the circuit. You can either make an adapter (I think there was an on-line document called "Mercury cell problem and its solution" or something like that where they explained how to do this) or soldering the diode inside the camera. The kind of skills requested for this work are very limitated, more or less just being able to use a soldering machine and paying a bit of attention to details. If I had to do this I would rather go for the adapter because if something goes wrong you can restart again and all what you have lost is a diode and a dead battery but you do not demage anything in the camera.

GLF
 
My M5 was adjusted for the modern battery by Sherry while she was doing a CLA and fixing the lens mount lock and the frame lever- works perfectly- these batteries last a lot longer than the Wein cells were- and are a lot cheaper.

I'll also chme in on the meter- it really is wonderful.

I just talked to Sherry the other day and am now using the ZM25 and 28 on the M5 with no more worries about damage.
 
Wein cells & Gossen Luna-Pro

Wein cells & Gossen Luna-Pro

I have M5s running on mercury cells & a Luna-Pro running on Wein cells. On several occasions I have checked the battery powered meters against my Weston Master V. All 4 meters match. So, I reckon the M5 meter would run just fine on the Wein cell. If the camera needs to go to Don or Sherry for other reasons, the meter could be calibrated for the alkaline cells at the same time. Whatever works for you.
 
Had an M5 that ran great on the Weins, was later adjusted for 1.5v cells - both great. Got better than advertised life from the Weins. The one thing that did not work well was using the ring from the Wein cell with a hearing aid battery. They're supposed to be 1.35v but every brand I tried was over 1.45 and it affected the meter readings.
 
I have one M5 that I modified by adding a Schottky diode inline thus allowing me to use a silver oxide 357 with a rubber "O" ring. The other one has a Wein cell in it.

Both meters match and are accurate.
 
ChrisN, cpborello, giellaleafapmu, sepiareverb, venchka, JNewell, and colyn, I really appreciate all of the information. I have the Wein cell ordered and just wanted to make sure I would not be doing damage to my M5 by using it.

I have read the entire "show us your M" thread a couple of times and I see that the M5 lovers are really committed to this M. I am looking forward to using mine.
 
It is a great camera- the 'other M'. Out shooting it today with the ZM25 alongside the M7/50. I am getting a bit impatient for the grip- the machinist told me another month- they've had a lot of higher paying regular clients this month. Once I have a workable grip for it I'll love it even more.
 
Sepiareverb -- can you post a picture of the grip after you have it complete? I'd be interested in seeing it.

Thanks,
Chris
 
Yes absolutely. The machinist is prepared to make up a number of them once we get it right- so if there is interest please let me know. I've not got even the first prototype done yet, so it is still a little soon, but I will certainly post pictures and some idea of pricing once we get close.

The idea is a grip that won't need to be removed to change film (I shoot a lot)
 
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Great idea!

Great idea!

sepiareverb said:
...The idea is a grip that won't need to be removed to change film (I shoot a lot)
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Could a way to center the camera & lens on a tripod be an added bonus? Sort of a RSS quick release plate + grip? Might be too much to ask for, eh.
 
i have three Wein Cell 1.35v batteries that are still new, but no camera to use them with.... so if anyone wants them drop me a message and i will mail them to you. free!

k.
 
humanized_form said:
i have three Wein Cell 1.35v batteries that are still new, but no camera to use them with.... so if anyone wants them drop me a message and i will mail them to you. free!

k.
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Thanks Kevin!
 
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