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Substitute Battery for Minolta Himatic 9
Although I have various cameras, I still use a Minolta Hi-Matic 9 that I bought in 1970. The preferred battery is a mercury battery, Energizer No. EPX625. Does anyone know of a replacement battery, the manufacturer and the number?
February 25, 2002
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John A. Lind |
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Michael,
You're not alone with this issue. Many cameras and light meters from this era use them. The original Mercury cells are 1.35 Volts. The "replacement" touted by the battery makers is a 1.5 Volt alkaline. I *don't* recommend them for cameras for two reasons:
(a) the voltage difference often throws the metering off by up to two stops.
(b) Mercury cells hold constant voltage until the bitter end; alkalines do not and gradually drop in voltage starting at about halfway through usable life. Even if the camera were recalibrated for 1.5 Volt batteries, the voltage falloff curve of an alkaline still throws metering off.The two most common solutions:
(a) The Wein 625 Zinc-air cell has the same shape/size as the original Mercury cell. Priced at about $8 to $9 each, these are 1.4 Volt cells, close enough to the Mercury for accurate metering. They also hold voltage until the bitter end. Although these were designed specifically as Mercury replacements and have a much longer life than standard hearing aid cells, they still to not last as long as the Mercury cells did. Once activated, they also have a very small internal drain that limits life, even when not being used. Any large camera store should have some Wein 625 cells, especially one that sells used gear.
(b) The C.R.I.S. Mercury adapter allows using a commonly available and inexpensive 1.5 Volt MS76 Silver Oxide cell to the size/shape and voltage of the PX625 Mercury cell. It's made of sturdy metal and contains a non-draining voltage regulating diode to drop the voltage to the proper value. This is the solution I've been using for a number of years now in two cameras. They are well made and work very well. Although they cost about $30, the low cost of MS76 (and equivalent) Silver Oxide cells pays back the cost of it in about three years compared to using the Wein Zinc-air. The MS76 cells, although smaller, last nearly as long as the original PX625 cells did. If you use one of these, it is *important* you use a Silver Oxide cell in it. Like the Mercury and Zinc-air cells, the Silver Oxide cells also hold voltage until the bitter end. You can order one of these directly from C.R.I.S.:
http://www.criscam.com/ -- John
February 25, 2002
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