Replacement Battery for Minox BL

Discussion in 'Minox' started by robert__|4, Dec 13, 1999.

  1. Does anyone know if there are substitutabke batteries for the 1.35
    volt PX -675 for the Monox BL? I have not had any luck with the local
    camera stores and battery supply stores. Can you substitute the 1.5
    volt 675 that is available for hearing aids? Thanks very much, Robert
  2. Bob, no, it is risky to use 1.5 v battery in BL. Use it at your own risk
    <p> You can buy Wein cell 1.35 v replacement cell for PX675 for $4.49 a piece
    from freestyle at catalog number #990-122
    <p> Tel 800-292-6137.
    <p> Or you may contact CRIS they sell adapter to convert silver oxide 1.5v cell into
    1.35v. Tel 800 216 7679. Fax 602 940 1329
  3. After lots of phone calls, I was able to locate some WEIN 1.35 675
    batteries for the Minox BL. I noticed it was very difficult to remove
    the Wein battery as the fit into the battery compartment was very
    tight. After examining the Owner's manual, I noticed reference to a
    cloth strap with a red dot, which is used as a pull strap to remove
    the battery. Unfortunately the Minox BL I have is missing this cloth
    strap, I was able to cut a thin strip of electrical tape and wrap it
    around the edge of the battery, so I am now able to remove it if
    needed. Thought this might be of interest if anyone has a the same
    problem with their BL battery compartment. Thanks to all who responded
    with help.
  4. I have been using S-76 silver oxide button cells in my BLs for some
    time now, with no noticeable difference over mercury originals. The
    problem with a Wein cell or any other zinc-air cell, is that they go
    dead very quickly once activated, and if this happens with film in
    the camera, you cannot change the battery without opening film
    chamber. The battery that Minox Labs is selling as a BL replacement
    is an A-76, which is the alkaline version of an S-76. Problem with
    Alkalines, though, is inconsistancy. They have a sloping discharge
    curve, silver oxides have a flat discharge curve, like mercury cells
    did. The only difference is a 1.5v rating versus 1.4v for the
    original mercury 675 battery. External dimensions are the same. As
    the Alkaline voltage starts out higher than the silver oxide on new
    cells then drops steadily lower, I reason that the silvers should be
    safer. Main difference is that the alkaline voltage does not remain
    consistent, silvers do. The silvers will put out the same voltage
    right to the end, then drop dead. I tested these against fresh
    mercuries in 4 different BLs several years ago, when mercuries were
    still available. I could not see any practical metering differences.
    Also compared against several zinc-air 675 substitutes, incuding
    regular and heavy duty 675 zinc-air hearing aid batteries (which are
    probably the same as, or similar to Wein cells). I cannot detect any
    individual changes when using the silvers compared to these. Of
    course, some of these old meters may be off in accuracy anyway. I
    have a BL that needs to be set at 50 ASA to get correct exposure
    readings on 100 ASA film speed, but it did this with mercuries too.
  5. Wein cell MRB675 1.35v has two air holes instead of four, hence it last longer.
  6. Adapter Mr-44 with silver oxide 392 cell
  7. I bought two pieces of MR44 adapters for my three BLs
    from Kanto Camera, Japan [​IMG]
  8. The Wein cell PX 675 is readily available from Amazon. As a physicist i see no reason why the S-76 would not work safely if it fits. But, depending on the meter circuitry, you might need to recalibrate exposure by ~10%. Say 1/3 stop.

    Pete Zimmerman

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