Yuasa Battery Co., Ltd.

Hideaki Igarashi

Kenjiro Kishimoto

Migaki Kono

A plate group is formed of positive and negative plates and separators formed mostly of glass fibers of a diameter not thicker than 1.0 micron and is inserted into a container. Then, a sulfuric acid electrolyte of a concentration of a viscosity increasing agent of 0 to 3.0% by weight is first poured in an amount smaller than the total pore volume of the plate group and a sulfuric acid electrolyte of a concentration of the viscosity increasing agent higher than in the above poured sulfuric acid electrolyte is then poured in so that the total poured amount may be the same as or larger than the total pore volume of the plate group. The sealed lead-acid battery obtained as mentioned above has an excellent discharge characteristic and gas recombining performance, is low in the internal resistance, is long in the service life and does not leak the electrolyte.

Process for producing sealed lead-acid battery

The invention involves to a maintenance-free type sealed lead-acid batteries. In such battery, a combined separator is of a double layer made by double laminating a sheet-shaped separator formed by entangling glass fibers of a diameter not larger than 1 micron as a base with glass fibers of a diameter not smaller than 5 microns or preferably of 10 to 30 microns and a porous member having a maximum pore diameter larger than of the sheet-shaped separator and the electrolyte consists of an aqueous solution of sulfuric acid in which a small amount of a viscosity increasing agent is present. The thus formed batteries are low in the cost and are high in the gas absorbing performance and life performance.

Sealed lead-acid battery

Separators for storage batteries, particularly separators for sealed lead-acid storage batteries, comprise glass fibers entangled in the shape of a sheet without the use of a binder, a first portion being glass fibers having a fiber diameter smaller than 1 micron and a second portion being glass fibers having a fiber diameter larger than 5 microns, preferably larger than 10 microns, as well as an average fiber length of at least 5 mm. The inventive separators have high electrolyte retention, good mechanical strength, and good shape recovery.

Growing community of inventors

Osaka, Japan

Hideaki Igarashi