Archived posting to the Leica Users Group, 2000/02/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Gentlemen, A battery replacement for my M5, SL, and MR4 meter, when I cannot obtain PX 625 batteries, is zinc air. Go to Wal Mart or any e\where hearing aid batteries are sold, and buy a 4 pack of 675 zinc air hearing aid batteries. These are slightly smaller diameter and thinner than a 625. Take one to a hardware store and buy a rubber grommet that fits around it fairly precisely there usually are several in their boxes. Then get a washer that is the same OD as the battery/washer. If you want to custom tailor this assembly take your camera as well. Put the cell in the grommet, and the washer on top. Zinc air cells are 1.4 Volts vs. 1.35 for mercury and 1.5 for alkaline. They are a great replacement, and very inexpensive. These cells, like reserve cells remain totally inactive (long shelf life) until you peel their tab. Thus you can have a number of them in your bag and replace them when they die. Once you peel the tab, it allows air to reach the cathode, activating the cell. True they do not have the long useful life of Mercury, but for their price I simply change them out every 4 months. Their discharge curve is very flat, excellent for meters. This will not work for all cameras. some such as the CL have a shaped cavity, requiring a 625, or Wein cell. For the MR. meter I make a cup out of Al foil. One caution, before storing your camera, take the batteries out and throw them out. Their is a chance that somePotassium Hydroxide electrolyte could leak. If it does, neutralize it with a little lemon juice on a Q tip, and install a new battery. any questions Email me. Bruce Bowman Killingworth CT