General Battery Corp. v. Gould, Inc.

• Decision Date: 19 July 1982
• Docket Number: Civ. A. No. 76-162,77-73.
• Citation: 545 F. Supp. 731
• Parties: GENERAL BATTERY CORPORATION, Plaintiff, v. GOULD, INC., Defendant. GOULD, INC., Plaintiff, v. GENERAL BATTERY CORPORATION, Defendant.
• Court: U.S. District Court — District of Delaware

545 F. Supp. 731

GENERAL BATTERY CORPORATION, Plaintiff, v. GOULD, INC., Defendant.

GOULD, INC., Plaintiff, v. GENERAL BATTERY CORPORATION, Defendant.

Civ. A. Nos. 76-162, 77-73.

United States District Court, D. Delaware.

July 19, 1982.

COPYRIGHT MATERIAL OMITTED

COPYRIGHT MATERIAL OMITTED

Paul E. Crawford, Connolly, Bove & Lodge, Wilmington, Del., for General Battery Corp., Frank J. Benasutti, and Eric S. Marzluf, Benasutti Associates, Ltd., Philadelphia, Pa., of counsel.

John G. Mulford, Theisen, Lank, Mulford & Goldberg, P. A., Wilmington, Del., for Gould, Inc.; Phillip H. Mayer, and Gordon R. Coons, Leydig, Voit, Osann, Mayer & Holt, Ltd., Chicago, Ill., of counsel.

OPINION

MURRAY M. SCHWARTZ, District Judge.

This is a consolidated action to determine whether two patents held by Gould, Inc. ("Gould") are valid and infringed. On May 6, 1976, General Battery Corporation ("GBC") filed Civil Action No. 76-162 in this Court, seeking a declaratory judgment as to the invalidity and non-infringement of Gould's product patent, U. S. Letters Patent No. 3,948,680 ("'680 patent"). On March 1, 1977, Gould filed Civil Action No. 77-73, alleging that GBC and Northwest Industries, Inc. had infringed the '680 patent and the subsequently-issued method patent, U. S. Letters Patent No. 3,988,165 ("'165 patent"). The two cases were consolidated by Court Order on October 3, 1977. Docket No. 53. Gould later dropped its claims against Northwest Industries, Inc. Docket No. 191.¹ The case was tried to the Court from November 30, 1981, to December 8, 1981, and the Court heard post-trial argument on April 30, 1982. Jurisdiction is based on 28 U.S.C. § 1338(a) and venue is proper under 28 U.S.C. § 1400(b). This opinion constitutes the Court's findings of fact and conclusions of law pursuant to Rule 52(a) of the Federal Rules of Civil Procedure.

I. Background Facts

A. Batteries Generally

The patents at issue claim both a method for manufacturing automotive batteries and the batteries themselves. The Gould batteries manufactured under the method at issue are known as "Drynamic"; the GBC batteries alleged to infringe are known as "Redi Dri." (PreTrial Order 1(a)(1)e.)² The process at issue became a commercial reality in the early 1970's. Batteries manufactured under this process are available commercially today.

Some background information on batteries must be set forth to place the case in context, although this discussion is necessarily oversimplified. Batteries generally are divided into two categories — primary or voltaic batteries, and secondary or storage batteries. Each type converts chemical energy which had been stored in the battery when it was charged into electrical energy. During this process, known as "discharge," chemical reactions occur within the battery which release electrons on the negative electrode. A primary battery is simply discarded after the reactants are exhausted. A secondary or storage battery, on the other hand, converts chemical energy into electrical energy by reactions that are essentially reversible; the battery may be recharged by passing a current through it in the opposite direction to that of its discharge.

At issue in this case are lead-acid storage batteries. Lead-acid storage batteries are composed of plates, which are grids with lead compound material pasted on them, and a solution of sulfuric acid and water called "electrolyte." When the battery is initially charged, a current which passes through the plates transforms them into either positive or negative plates by rendering the inert lead compound material "active." The active material on the positive plates is lead dioxide; the active material on the negative plate is spongy lead. At discharge, the sulfuric acid reacts with this active material to form lead sulfate and water and release electrical energy.³

An automotive battery is simply a six or twelve-volt lead-acid battery that is used to start an automobile engine. (Tr. 103). Among battery manufacturers these batteries are often termed "starting, lighting, and ignition" or "SLI" batteries. (Tr. 103). Unlike industrial batteries⁴ or golf cart batteries, which normally use from fifty to one hundred percent of their capacity during operation, an automotive battery usually uses less than five percent of its total capacity to start an engine. (Tr. 110). In addition, an automobile battery is recharged while the engine is running. When the battery is in a state of overcharge, as is the ordinary case while driving, the electrical current from the alternator dissociates water into hydrogen and oxygen gas, which escapes through openings in the top of the battery. (Tr. 110-11).

Typically, an automotive battery has a plastic container with a plastic cover which is hermetically sealed. At the top of the battery, protruding from the cover, are the lead terminals or outputs. The cover also contains six openings, arranged in groups of three, which are called vents or fill openings; the bottom portions of the vents as they go through the cover are called vent wells. Partitions or cell walls within the battery separate the interior of the battery into six individual cells. Each cell contains one element, which consists of alternating positive and negative plates kept apart by separators made of non-conductive material, such as wood, rubber, or plastic. Lead straps connect all the positive or all the negative plates in each cell, and inter-cell connections connect one group of plates of one charge to the group of the opposite polarity in the next cell. The plates sit on elevations in the battery floor known as "restups" or "mudrests" rather than directly on the floor of the battery case. The space between the bottom of the plates and the floor is called the "mudwell," an area into which some of the material from the plates may fall during the life of the battery. (See generally Tr. 105-07; PX1a; PX1b; PX2.)

Battery acid, known as electrolyte, is used in varying concentrations in the formation and operation of batteries. The concentration of acid to water is measured by determining the solution's specific gravity, defined as the ratio of the density of a substance to the density of water at a given temperature. Water has a specific gravity of 1.0; as sulfuric acid is added, the specific gravity goes up. A so-called "high gravity" acid might be thirty-five percent sulfuric acid; a "low gravity" acid could have as little as five percent acid. Generally the desired specific gravity of electrolyte in a finished battery is approximately 1.265 at 25° C, which would be about thirty-five percent sulfuric acid. (See Tr. 250-51; DX34).

In the manufacture of automotive batteries, the process of charging a battery in its initial state is called formation. At formation, the inert material pasted onto the battery plates is converted to the active state by passing a current through the plates. Two methods of manufacture are commonly used in the battery industry — the "one-shot" and "two-shot" methods. In "two-shot" formation, an assembled battery⁵ is filled with low gravity acid in the range of 1.050 to 1.060 and charged so that most of the inactive material is converted to active. The acid is then removed or dumped from the container and the container filled with a higher gravity acid. The combination of that acid with the low gravity acid remaining in the plates produces the desired final level of specific gravity of 1.265. After a boost charge is applied to mix the low and high gravity acids, the vents are inserted in the top of the battery and the battery is ready for shipment. (See Tr. 246-49; PX53). In contrast, a "one-shot" formation uses a formation acid with a high enough specific gravity so that only one fill is required. (Tr. 249-50). Both processes have been known for years and are considered to have different advantages. (Tr. 251-52).⁶

A problem frequently encountered in batteries, and relevant to this case, is known as "sulfation." Sulfation generally refers to the formation of lead sulfate on the surface and in the pores of the active material of battery plates. As noted earlier, some sulfation occurs as a natural part of discharge, produced by the reaction of sulfuric acid with the plates. This type forms a finely crystalline sulfate which is easily reduced by a charging current. Sulfation also occurs from self-discharge, and depends on the concentration and temperature of the electrolyte as it acts on plate materials. This sulfation can also be easily reduced by charging current, although the crystals are coarser. The most common use of the term "sulfation," and the use relevant to this case, is the formation of large lead sulfate crystals or crust on the plates as a result of neglect, misuse, or nonuse, as, for example, when a battery is charged and stored on a shelf awaiting sale. Such sulfation is more difficult to reduce with charging current and may injure the plates; as the pores of the plates become clogged with sulfate, the active material may be pushed out of the plates and the plates buckled. See G. Vinal, Storage Batteries 295-97 (2d ed. 1930) (PX137, Tab C).

The automotive battery market today is divided between original equipment manufacturers and the aftermarket. For original equipment manufacturers, perishability of batteries is not a significant factor because of the large quantity of batteries produced and their rapid turnover. Eighty percent of automotive batteries, however, are sold in the aftermarket, where longer shelf life is desirable. Smaller retailers who sell fewer batteries, slower-moving batteries, and seasonal temperature variations which affect shelf life as well as sales all make perishability an important consideration. (Tr. 167-70). A shelf life of six months would be the usual requirement, but for some slow moving batteries a year's shelf life would be required. (See Tr. 170, 172-74).

In 1970, two main types of automotive batteries existed — "wet...