Abstract: This invention pertains to novel alkaline electrochemical cells having high drain capacities, especially cells having high drain rate capabilities at voltages of at least 1.1 volts for use in small appliances such as hearing aids. The anode includes anode material in the cells including potassium hydroxide, zinc powder, 0.02% to 0.5% of a reaction rate enabling compound selected from a compound of indium, cadmium, gallium, thallium, germanium, tin, or lead, with indium compounds being preferred. The anode material optionally further includes a low level of mercury, and preferably a surfactant comprising hydroxyethylcellulose. The cathode provides sufficient oxidative capability to oxidize the zinc at a sufficient rate to support the electrical drain demands on the cell. A cathode, in a preferred zinc air cell for a hearing aid, includes at least 5 air ports, evenly distributed over the surface of the bottom of the cathode can.

Abstract: This invention pertains to novel electrochemical metal air cells having improved closed circuit voltage characteristics. The improved voltage characteristics are illustrated at a constant load of 51 ohms. The closed circuit voltage during an initial placement into use of the cell of the invention has a decreased voltage drop relative to prior art cells, and recovers to a higher voltage. For example, the closed circuit voltage of the metal air cell drops to a minimum voltage during the first 20 seconds of initial placement into use. The minimum voltage is no more than 22% less than the initial open circuit voltage. This voltage drop is less than the voltage drop of other known metal air cells at 51 ohms. Metal air cells of the invention recover, during the first minute of use, to a closed circuit voltage of at least 79% of the initial open circuit voltage. The value of the open circuit voltage of the metal air cell of the invention is preferably about 1.43 volt.

Abstract: This invention pertains to novel alkaline electrochemical cells having high drain capacities, especially cells having high drain rate capabilities at voltages of at least 1.1 volts for use in small appliances such as hearing aids. The anode includes anode material in the cells including potassium hydroxide, zinc powder, 0.02% to 0.5% indium as indium compound separate from the zinc powder, optionally a low level of mercury, and preferably a surfactant comprising hydroxyethylcellulose. The cathode provides sufficient oxidative capability to oxidize the zinc at a sufficient rate to support the electrical drain demands on the cell. A cathode, in a preferred zinc air cell for a hearing aid, includes at least 5 air ports, evenly distributed over the surface of the bottom of the cathode can. Cells of the invention exhibit prolonged operation at relatively constant voltage over 1.

Abstract: A battery, a battery charger, and a battery charging system are used for charging cylindrical batteries having a certain predetermined feature. The battery charger has at least one compartment having first and second circular recesses provided at the rear wall of the at least one compartment for engaging the cathode terminals of batteries having the predetermined feature of a first and second size respectively, wherein the recesses are of such dimensions as to receive the cathode terminals of batteries having the predetermined feature, but not the cathode terminals of conventional, prior art primary and secondary batteries not having this feature. It provides a safe, easy to use, low cost battery charging system that will not charge undesired primary or secondary batteries.

Abstract: A charger for a rechargeable alkaline manganese (RAM) battery has a positive contact which engages against the positive terminal of a compatible battery without making electrical contact with the positive terminal protruding nubbin. A rechargeable battery has an insulating jacket which surrounds the battery side wall but which does not overlap the positive terminal. Hence the charger positive contact may engage against the specially adapted battery and electrical contact, but will not make electrical contact with a conventional battery having a partially insulated positive terminal. Alternatively, the battery positive terminal may be insulated within less than 0.040 inches of the battery perimeter and be charged by protruding positive contacts spaced inwardly from the perimeter by approximately the same amount.