Mamiya 7 battery finicky?

[kaiyen]

Hi all,
I got what appeared to be a rather minty Mamiya 7 off ebay for a solid price recently. Put in 2 CR1/3N batteries and...nothing. Will not turn on. Ordered 4 LR44 batteries to see if it's just a bad set of CR1/3 I got or if the camera is finicky. Or if it's just a dud and I'll have to return it.

Anyone ever had issues with batteries for these guys before? Any tricks I need to know about? Will be really sad if I have to return this...

 

[ka7197]

Huh!? Set of batteries?

The Mamiya 7 (and 7 II) takes one 6 V battery. You can use either an alkaline cell type 4LR44 or a silver-oxide cell type 4SR44 or a lithium cell type 28L or 2CR1/3N. Alkaline cells are the cheapest (but perfectly fine for regular use), silver-oxide are the strongest (good for frequent use and/or at freezing temperatures), and lithium cells have the longest shelf-life (good for infrequent use).


EDIT: Uh oh ... it just occurred to me you might have confused one 6 V 4LR44 cell with four 1.5 V LR44 cells. Please note: '4 LR44' and '4LR44' are two different things — mind the gap! Same goes for '2 CR1/3N' (two 3 V lithium cells) and '2CR1/3N' (= one 6 V lithium cell).

 

[kaiyen]

Thanks. Yes, it is quite difficult deciphering what type of battery is intended. I think I have a lead on the 28L that might help. I could not find 2CR1/3, for instance, at all, but now see that the 28L is a replacement for it.

Thanks! I'm on it!

 

[Sal Santamaura]

Get either of these:

https://www.freestylephoto.biz/04028-Varta-PX28-4G13-544-4SR44-6.2-volt-Silver-Oxide-Battery
​

https://www.bhphotovideo.com/c/product/1062384-REG/exell_battery_s28px_6v_silver_oxide.html​

 

[ka7197]

I could not find 2CR1/3N, for instance, at all, but now see that the 28L is a replacement for it.

It's not a replacement; it's just another name for the same thing.

 

[wwfloyd]

Hi all,
I got what appeared to be a rather minty Mamiya 7 off ebay for a solid price recently. Put in 2 CR1/3N batteries and...nothing. Will not turn on. Ordered 4 LR44 batteries to see if it's just a bad set of CR1/3 I got or if the camera is finicky. Or if it's just a dud and I'll have to return it.

Anyone ever had issues with batteries for these guys before? Any tricks I need to know about? Will be really sad if I have to return this...

If the 4 x LR44 stack fits, then, you may find that putting a single layer of scotch tape around them will get them working -- temporarily, at least. That's what I do with my Minox 35GL. The proper battery would have this insulation in place, already.


Depending on the contact springiness, you may have to work to ensure that contacts are made, all the way through the stack. I put partial slits through the tape, to weaken it, and make contact easier.

 

[ka7197]

If the 4 × LR44 stack fits ...

It should fit and, in theory at least, also work properly. After all, four stacked 1.5 V LR44 cells are the same size and voltage as one 6 V 4LR44 cell — hence the name. Of course, the polarity must be obeyed. The battery (or stack of batteries) must go into the Mamiya 7's battery chamber the minus pole first ... so right before replacing the battery chamber's cover, you should see the battery's plus pole. Maybe a small piece of aluminum wrap between the stack's final plus pole and the battery chamber's cover will help to ensure good electrical contact.

 

[mickster]

...and to add to the Mamiya 7 battery FAQs; OP, if you still have problems after fitting the correct battery the right way up, try cleaning the gold contacts on body and lens with deOxit (or even a pencil eraser)...mine seem to need a quick clean if the camera hasn't been used for a few months. The symptom for this is no - or a flickering - meter display.