Abstract: A charging circuit includes a first power source circuit that supplies charging power to secondary batteries; a switch that controls the supply of the power; and a control device that performs switching control of the switch. The control device detects a voltage difference between the secondary batteries before starting charging; starts a timer and starts serial charging of the secondary batteries; on the condition that the voltage difference before the charging has been equal to or larger than a first threshold, if respective voltage values of the secondary batteries have both become equal to or larger than a second threshold before the timer expires, shortens a remaining time on the timer at that time point; and finishes the serial charging of the secondary batteries at the earlier of a time point when the secondary batteries have both become fully charged, or a time point when the timer has expired.

Abstract: A charging circuit includes a first power source circuit that supplies charging power to secondary batteries; a switch that controls the supply of the power; and a control device that performs switching control of the switch. The control device detects a voltage difference between the secondary batteries before starting charging; starts a timer and starts serial charging of the secondary batteries; on the condition that the voltage difference before the charging has been equal to or larger than a first threshold, if respective voltage values of the secondary batteries have both become equal to or larger than a second threshold before the timer expires, shortens a remaining time on the timer at that time point; and finishes the serial charging of the secondary batteries at the earlier of a time point when the secondary batteries have both become fully charged, or a time point when the timer has expired.

Abstract: A battery pack having a plurality of battery cells stored side by side in a case. The case, in particular, includes a bottomed trough and a lid, the trough having a space as a cell storage portion defined between inner and outer wall portions paired to form a loop and a space as a hollow surrounded by the inner wall portion and penetrating the trough from top to bottom, the lid closing a top opening of the cell storage portion. The battery cells are arranged in a loop along the inner and outer wall portions, whereby a rise and variation in their temperature can be restrained.

Abstract: Provided is a hydrogen absorbing alloy superior to the MmNi5 system hydrogen absorbing alloy and the TiFe system hydrogen absorbing alloy that are widely put to practical use in both the capacity density per unit volume and the capacity density per unit weight. The hydrogen absorbing alloy of the present invention is also superior to the conventional TiMn2 system hydrogen absorbing alloy in the initial activation. The hydrogen absorbing alloy of the present invention is represented by a general formula AMx, where A is at least one element selected from IA group, IIA group, IIIB group, and IVB group of the periodic table, and M is at least one element selected from VB group, VIB group, VIIB group, VIIIB group, IB group, IIB group, IIIA group, IVA group and VA group of the periodic table, x meets the relationship of 2.7<x<3.8, and an average atomic radius r meets the relationship 1.36 Å≦r≦1.39 Å.

Abstract: A coating die is disclosed, in which a slit-like spacing 29 is formed between a pair of die elements 25, 27 arranged in opposed relation to each other. A band-shaped electrode sheet 23 is movable along the length of the spacing 29. The sides of the slit-like spacing along the width of the electrode sheet 23 are enclosed. An electrode piling agent is supplied from an external source into the die element pair 25, 27 through supply flow paths 47, 49. Discharge ports 47a, 49a of the supply flow paths 47, 49 are open to the slit-like spacing 29. The portion of the spacing 29 downstream of the discharge ports 47a, 49a in the direction of movement of the electrode sheet 23 has a thickness equivalent to the thickness of the electrode sheet 23 plus the thickness of the electrode piling agent coated on the two sides of the electrode sheet 23. The portion of the spacing 29 upstream of the discharge ports 47a, 49a has a thickness substantially equal to the thickness of the electrode sheet 23.

Abstract: A nickel-metal hydride secondary cell comprising an enclosure, a non-sinter type nickel positive electrode accommodated in said enclosure and formed of a conductive core and a layer formed on the core and made mainly of a binding medium, nickel hydroxide powder, and cobalt monoxide powder, a hydrogen absorbing alloy negative electrode accommodated in said enclosure and formed of punched metal and a layer formed on the punched metal by applying a paste thereto, said punched metal having a plurality of apertures having a diameter of 1 to 5 mm at an aperture rate of 45 to 70% and having a thickness equal to 10 to 35% of the overall thickness of the negative electrode, and said paste made of 100 parts by weight of hydrogen absorbing alloy powder, 0.005 to 1 part by weight of polyacrylate, 0.01 to 1 part by weight of carboxymethylcellulose, 0.5 to 7 parts by weight of fluoro-resin, and 0.

Abstract: A nickel-metal hydride secondary cell comprising a non-sinter type nickel positive electrode accommodated in an enclosure and comprised of a conductive core and a layer formed on the conductive core, the layer made of a mixture of nickel hydroxide power and cobalt monoxide powder covered with a layer of high-valence cobalt oxide, a hydrogen absorbing alloy negative electrode accommodated in the enclosure and comprised of a conductive core and a layer formed on the conductive core and made of a mixture hydrogen absorbing alloy powder and carbon black having a specific surface area of 700 m.sup.2 /g or more, and having a capacity 1.0 to 2.5 times the sum of the capacity of the nickel hydroxide contained in the positive electrode and the electricity required to oxidize the cobalt monoxide powder, a separator made of synthetic resin unwoven fabric having a texture size of 50 to 100 g/m.sup.2 and a thickness of 0.1 to 0.

Abstract: Disclosed is a hydrogen storage alloy electrode prepared by integrating a mixture of a hydrogen storage alloy powder, an electrical conducting powder and a polymer binder with a current collector, characterized in that the polymer binder is composed of a polyacrylic acid salt and polytetrafluoroethylene as essential components, and that the hydrogen storage alloy powder is coated with polyacrylic acid salt, wherein the three-dimensional reticulate molecular chain of the polyacrylic acid salt itself is partially severed.