Abstract: A process for the production of a lead accumulator comprising installing electrode plates and separators in a battery box, introducing an electrolyte in the form of a thixotropic gel including sulphuric acid and gel-forming agent into an electrolyte space and, closing of the battery box, wherein after installing the electrode plates the entire amount of sulphuric acid required for a desired electrolyte concentration is introduced into an electrolyte space within the box to form the electrode plates and after formation, an aqueous silica sol with 15 to 60% by weight of solids component, with a specific surface area of solids of 100 to 500 m.sup.2 /g, is added in such an amount that a solids concentration of the electrolyte, with respect to the overall weight thereof, of 3 to 20% by weight is obtained, and then the content of the electrolyte space is homogenously mixed.

Abstract: Enclosure for a battery of accumulators, including at least one wall. Provision is made to circulate a heat-transfer fluid in the vicinity of the wall. The structure for circulating the heat-transfer fluid includes, on the wall, an additional wall which extends substantially parallel to the wall of the enclosure and whose periphery is joined in a sealed manner to the wall of the enclosure, so that a space for the heat-transfer fluid is delimited between the wall of the enclosure and the additional wall, and at least one inlet orifice and one outlet orifice emerging into the space in order to allow circulation of the heat-transfer fluid.

Abstract: An electrolyte for a lead acid accumulator containing 5 to 30 g per liter of pyrophosphoric acid and 5 to 50 g per liter of orthophosphoric acid, the total quantity of phosphoric acid in the electrolyte being less than or equal to 60 g per liter.

Abstract: A lead based alloy for electrode supports of a lead-acid storage cell, the alloy containing between 0.05% and 4% antimony between 0.02% and 0.3% magnesium, and no barium. The magnesium permits a reduced antimony content, thereby reducing the corrosion, self-discharge, and hydrogen-releasing overvoltage problems caused by the presence of antimony in electrode supports, without adversely affecting the beneficial mechanical properties provided by antimony. It is essential to have no barium, which causes cracking and high mass corrosion of the alloy during use in a lead-acid cell.

Abstract: An electrode for a lead-acid storage cell, electrode containing an active material (8), an active material support and at least one electric conductor which includes a core (10) made of a metal whose electric conductivity is higher than that of lead. Said core is coated with a protective layer (11) made of a substance chosen from the group comprising titanium, tungsten, tantalum, niobium, zirconium and alloys thereof.

Abstract: Apparatus for automatically feeding bushings into a press for moulding covers for storage batteries. It includes a pipe (1) for conveying the bushings (6), said pipe being divided into branches (8, 9, 10, 11) each of which communicates with a bore (28, 28') provided in a first moving part of the press (2), push rods being linked to the stationary part of the press (2), which push rods can each be inserted in one of said bores (28, 28') during the translation movement of said moving part, studs being provided on a second moving part of the press (2) and each being disposed adjacent to one of said bores so that firstly, before moulding when the press is closed by the translation movement of the two moving parts such that they abut against the stationary part of the press (2), the push rods push a bushing (6) into each bore (28, 28') until the bushing mates with the stud and secondly, after moulding when the press (2) is opened, another bushing ( 6) drops by gravity into the bore at the end of said push rod.

Abstract: Low antimony alloys of lead are used for casting electrode supports in lead accumulators. They include less than 4% antimony by weight to avoid various poisoning effects of antimony on the electrochemical processes involved. Such alloys tend to have grains of excessive size which can lead to brittle castings. To reduce the grain size the present invention includes an additive constituted by a rare earth or a mixture of rare earths, e.g. misch metal at between 0.001% and 1% by weight, and preferably at 0.2%. The invention also provides an electrode support cast from the alloy, an electrode including such a support and a lead acid battery including such electrodes.

Abstract: The protector has two ends connected to a central portion, these ends being hollow and each suitable for covering one of the two terminals of two contiguous cells of the battery, the central portion being hollow and being able to cover the connection or strap between said terminals, the upper surfaces of said ends having openings or gaps separated by strips of material, the upper surface as well as the side surfaces of said central portion also having openings or gaps separated by strips of material. The area of said openings or gaps is about twice as great as that of the total area of the strips.

Abstract: A maintenance-free lead storage battery comprises a container closed by a lid and containing an acid electrolyte together with a block of positive plates, negative plates and separators. The block of plates and separators is tightly packed in a case which is immersed in the electrolyte and which has openings in those of its walls which are in close contact with end ones of said plates.

Abstract: A battery of series-connected storage cells is checked by:Measuring the transient elementary open-circuit voltage at the terminals of each storage cell;Comparing the said elementary voltages with the average transient voltage of the said storage cells (i.e. with the total transient open-circuit voltage divided by the number of storage cells). The battery is rejected if the difference between the said average transient voltage and one of the said elementary transient voltage becomes greater than a predetermined threshold.BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a method and a device for checking a storage battery, more particularly a lead acid storage battery, charged and filled with electrolyte, this checking being effected in principle when the battery comes off the production line.2.

Abstract: A method of checking a storage battery with series-connected cells comprises the steps of:Passing a charging current pulse through the battery,Measuring an elementary transient voltage at the terminals of each storage cell; andComparing elementary transient voltages with the average transient voltage of the said storage cells (total transient voltage divided by the number of storage cells).The battery is rejected if the absolute value of the difference between the said average transient voltage and one of the elementary transient voltages, when the difference maintains a constant sign, becomes higher than a predetermined threshold and, when the difference changes signs, if the sum of the maximum absolute values of the differences in constant sign becomes higher than a predetermined threshold. Application: checking lead-acid storage batteries when they come off the production line.

Abstract: Seal in the cover of a storage cell for a malleable metal terminal post such as lead or indium terminal post provided with a blind hole opening towards the outside and a shoulder inside the storage cell. A flexible gasket is situated between the cover and the shoulder. An expandable rivet or the like is inserted in the blind hole and has a head that bears on the external face of the cover. Extraction of the rivet expands and shortens the terminal post and compresses the flexible gasket into sealing relationship between the shoulder and the cover without causing the expanded portion of the terminal post to come into contact with the cover thus avoiding danger of cracking the latter. Application is to small sealed lead storage cells.

Abstract: A separator for a galvanic element wherein partially fused glass fibers are coated by a coating consisting of grains of thermo-hardening synthetic material immersed in a natural or synthetic latex to mechanically reinforce the knots in the glass fiber network resulting from partial fusion of the glass fibers without blocking the pores of the partially fused fiber network.