MXPA98001828A - Condition tester for a bate - Google Patents

Abstract

A condition indicator assembly (tester) (10) is disclosed to determine the condition of a main cell, for example a battery. The condition indicator assembly may comprise an electrochemical, indicator cell (20), connected in series to an auxiliary cell (25). The indicator cell and the auxiliary cell each have one anode (47), cathode (43) and electromotive force (f.e.m.) own. The condition indicator assembly can be permanently connected in parallel to the terminals of a main cell that is being tested. The condition indicator assembly is sufficiently thin, so that it can be integrated into a label for the main cell. When the main cell is discharged, the anode of the indicator cell is clarified proportionally to the discharge of one of the electrodes from the main cell to provide a visually discernible, continuous indication of the state of the cell.

Description

CONDITION TESTER FOR A BATTERY DESCRIPTION OF THE INVENTION This invention relates to a condition tester for determining the condition of a main cell or battery and is integrally related to the tester thereof. The invention relates to the electrochemical state of load testers. The electric primary cells that include several devices to visually indicate the condition or state of charge of the cell have already been described. Known indication devices include, but are not limited to, chemical indicators which react with materials within the battery, chemical indicators located externally to the battery, elements included within an electrode that become visible during discharge, and thermochromic materials in thermal contact with a resistive element that is adapted to be connected through the ateria. One problem with many of these indicators is that the indication of their indication is sensitive to the construction geometry of the indicator or - inside the battery. Therefore, the natural variations that inherently occur during manufacturing lead to variability, from battery to REF: 27032 battery, in time during discharge when the indication occurs. Commercially available testers for determining the condition of an electrochemical cell are typically of the thin film type of heat response. This type of tester contains a thermochromic material in thermal contact with an electrically conductive element. Such testers are commercially available in the form of strips which are not integrated into the cell or label of the cell. To use the tester, it must be applied to the terminal ends of the cell being tested. Examples of such testers and their application are described in U.S. Patent Nos. 4,723,656 and 5,188,231. These testers work well to intermittently test a battery during its useful life. They are harder to permanently attach to a battery because the visual indicator is a thermochromic material. Care must be taken to thermally insulate the indicator from the battery frame to prevent heat transfer that could interfere with the proper operation of the indicator. Additionally, the electrically conductive element is connected in series with, and depletes the battery during the test. Therefore, the electrical contacts of the tester should not be permanently connected to the battery terminals in the absence of an activatable contact device, otherwise the battery could be discharged prematurely through the tester. Another type of battery tester is an electrochemical tester which has its own electromotive force (ph.e.m.) as described in US Patent 5,250,905 and US Patent 5,396,177. The indicator cell is designed to have approximately the same open circuit voltage (VCA) as the main cell during discharge. In such case the indicator cell can be connected directly in parallel to the main cell. Such a tester has the advantage that it can be permanently connected to the battery being tested and does not require activatable contact devices. This type of tester provides visual indication of the degree of discharge of the battery by the degree to which a thin metal film is separated or electrochemically rinsed to reveal a different colored background. The colométricos devices can take control of the colors of electric charge that pass through the electronic equipment with which they can be associated. Examples of colometric devices that use the electrochemically induced charge along a column of mercury to give the visual indication of the amount of charge that passed are written in U.S. Patent 3,045,178 and 3., 343.083. Colometric devices that do not have their own electromotive force are in effect electrolytic cells. The invention will be better understood with reference to the drawings in which: Figure 1 is a circuit diagram showing the connection of the condition indicator (mounting tester) of the invention to the main cell that is being tested with portion voltage of the indicator cell smaller than the voltage of the main cell. Figure IA is a circuit diagram showing the connection of the condition indicator assembly of the invention to the main cell being tested with the voltage of the portion of the indicator cell greater than the voltage of the main cell. Figure 2 is a cut away perspective view of the condition indicator assembly referred to in Figure 1. Figure 2A shows a battery having a condition indicator assembly permanently connected to the condition indicator assembly in a view in partial cross section shown elongated. For the purposes of the following discussion the electrochemical cell or battery that is being measured will be referred to as the "main cell" and the electrochemical cell that will display the indication will be called the "cell dicacc ra". The invention is directed to a condition indicator assembly (tester), which is electrically connected to and visually indicates the condition of a main cell or battery. The condition indicator comprises an indicator cell which is a thin film electrochemical cell comprising an anode, a cathode and an electrolyte in contact with at least a portion of both the anode and the cathode. The indicator cell has an anode and a cathode of different matter and a finite electromotive force (f.e.), typically, greater than 100 millivolts, for example, of about 100 millivolts and 1.5 volts. It has been determined in the present invention that the indicator cell can be designed to have an open circuit voltage that is greater or less than that of the main cell being tested, if an auxiliary cell has a finite electromotive force (fem). ) is connected in series with the indicator cell to compensate for the difference in the open circuit voltage between the indicator cell and the main cell. That is, one of the anode and the cathode of the auxiliary cell is electrically connected to one of the anode and the cathode of the indicator cell. The electrode subtracts from the auxiliary cell and the remaining electrode of the indicator cell is electrically parallel to the terminals of the main cell. During the discharge of the main cell, the reaction begins at the visible electrode of the indicator cell and continues to the remote regions thereof. During the discharge of the main cell being tested the open circuit voltage of the condition indicator comprising the indicator cell and the auxiliary cell is similar to the open circuit voltage of the main cell, preferably within (more or less ) approximately 300 millivolts of the open circuit voltage of the main cell. In the arrangement of the circuit, described in Figure 1, the condition indicator 10 comprises an indicator cell 20 and an auxiliary cell 25. The indicator cell 20 and the auxiliary cell 25 are electrochemical cells that have their own finite electromotive force (emf) . In the arrangement of the circuit described in Figure 1 the open circuit voltage (VCA) of the indicator cell 20 is smaller than the open circuit voltage of the main cell 30. In this case the anode of the auxiliary cell 77 is electrically connected to the cathode of the indicator cell 43, the cathode of the auxiliary cell 83 is connected to the cathode of the main cell 145, and the anode of the indicator cell 47 is connected to the anode of the main cell 115. (The anode of any of the auxiliary cell 25 or indicator cell 20 was defined as the electrode that is being oxidized and thus releasing electrons It should also be understood that there are internal resistances associated with each of the main cell 30, the indicator cell 20 and the auxiliary cell 25). In the arrangement of the circuit of Figure 1, the open circuit voltage of the indicator cell 20 is added to the open circuit voltage of the auxiliary cell 25, so that the combined open circuit voltage of the condition indicator 10 as a whole , that is, between the cathode 83 of the auxiliary cell 25 and the anode 47 of the condition indicator cell 20 is approximately the same as the open circuit voltage of the main cell 30. The capacity of the indicator cell 20 is much lower that the capacity d - the main cell 30 and the combined internal resistance of the indicator cell 20 and the auxiliary cell 25 is much greater than that of the main cell 30. The much greater resistance of the condition indicator assembly 10 allows the indicator cell 20 is discharged at a much faster rate than that of the main cell. This is a requirement, since the indicator cell 20 has a much lower capacity compared to the main cell. During the discharge of the main cell 30, the current ratio,? ^, Through the main cell-current, it, through the indicator cell can be a constant, so that the percent of depletion of a; The anode or the cathode of the auxiliary cell will be aprc? irro.e: .- or: .the same as the per cent depletion of one of the anode or cathode of the main cell. In this way, a visual indication showing the percent depletion of one of the electrodes of the indicator cell can be used to reflect the state of charge of the main cell 30. In the arrangement of the circuit, described in FIG. of condition 10 comprises an indicator cell 20 and an auxiliary cell 25. In the arrangement of the circuit described in Figure IA the open circuit voltage (VCA) of the indicator cell 20 is greater than the open circuit voltage of the main cell 30 In this case the cathode of the auxiliary cell 83 is connected electrically: to the cathode of the indicator cell 43, the anode of the auxiliary cell 77 is connected to the cathode of the main cell 145, and the anode of the indicator cell 47 is connected to the cathode of the main cell 145. connected to the anode of the main cell 115. In such arrange the open circuit voltage of the auxiliary cell 25 reduces the open circuit voltage of the open circuit voltage of the indicator cell 20, of m All of the open circuit voltage D of condition indicator 10 as a whole, ie, between the anode "? of the auxiliary cell 25 and the annulus 47 of the condition indicating cell 20 is approximately the same as the open-circuit voltage of the main cell 30. The same effect as coneetand can also be obtained in this case; the anode 47 of the indicator cell 20 to the anode 77 of the auxiliary cell 25, connecting the cathode 43 of the indicator cell 20 to the cathode 145 of the main cell 30 and connecting the cathode 83 of the auxiliary cell 25 to the anode 115 of the cell main 30. The condition indicator 10 comprising an indicator cell 20 and the auxiliary cell 25 is shown in Figure 2 in an array consistent with the circuit diagram of Figure 1. The condition indicator 10 can be permanently connected to a main cell 30 (Figure 2A), such as a conventional alkaline cell, for example, by integrating this to the label for the main cell. Since the discharge profile of the open circuit voltage through the condition indicator 10 is approximately the same as the discharge profile of the open circuit voltage of the main cell 30, the current flow relationship through the main cell The flow of current through the auxiliary cell remains almost constant. This can be the case regardless of the load on the main cell. Thus, at any time during the discharge of the main cell, the depletion percent of one of an anode or control cathode of either the indicator cell 20 or the auxiliary cell 25 will be approximately the same as the percent of Exhaustion of an anode or control chamber of the main cell 30. (If the quantity of active material of the anode or active material of the cathede in either of the main cell 30 or the indicator cell 20 is in excess, the comparison of the percent Exhaustion between two cells should be done using the electrode that does not contain excess active material.The electrode that is not in excess is referred to here as the control electrode). Typically, the percent depletion (clearance) of the anode 47 of the indicator cell 20 can be used to reflect the percent depletion of a control electrode in the main cell. This can be used to provide a continuous visual indication of the condition (state of charge) of the main cell. The percent of active rm.zerial remaining in the indicator cell 20 may be discernible at any time during the life of the main cell. For example, if the indicator anode 47 is being depleted, the anode can be visually discerned and a graphic scale can be placed near the anode indicating the percentage of charge remaining in the main cell 30 and / or if the main cell needs to be replaced. . The condition indicator 10 can be connected in paralwith the main cell 22 'which is being tested, for example, as illustrated in the circuit diagram of Figure 1. In Figure 1 the main cell 30 is shown schematically with the term. r; 115 and positive terminal 145. In use, when main cell 30 is connected to a load 38 and discharged, current iL flows through load 38, and current iM flows through main cell 30. and the current it flows through the condition indicator 10 so that iL = iM + iM. In the circuit configuration of Figure 1, the main cell is a conventional AA size alkaline cell having an internal resistance of about 0.1 ohm during normal operation, the combined internal resistance of the indicator cell 20 and the auxiliary cell 25 is typically at least 1 4 times, more typically between about 10'1 and 10h times the internal resistance of the main cell 30. It should be noted that the total resistance of the condition indicator 10 can be adjusted by altering the internal resistance of each of the indicator cell 20 and auxiliary cell 25 or adding resistors in series with those two cells. In a preferred embodiment the condition indicator 10 (tester assembly) as shown in Figure 2 comprises an indicator cell 20 electrically connected in series to an auxiliary cell 25 in the form corresponding to the arrangement of the circuit of Figure 1. The indicator of condition 10 (tester) has a thickness of less than 100 mils (2.5 mm), preferably a thickness of between about 2 and 100 mils (0.05 and 2.5 mm), more preferably a thickness of between about 2 and 15 thousandths of an inch (0.05 and 0.4 mm). The auxiliary cell 25 is a thin, miniature energy source which at least partially activates the indicator cell 20. The main cell 30 can be a primary or secondary battery and typically can be a conventional alkaline cell. The condition indicator 10 can be integrated into the label for the main cell 30, for example, attaching it to the internal surface of the label. The indicator cell 20 contains an anode 47 and a cathode 43 composed of different materials in contact with an electrolyte. The indicator cell 20 and the auxiliary cell 25 are unloaded Ideally in proportion to the discharge of the main cell 30, regardless of the load 38. For example, the indicator cell 20 can be calibrated so that during discharge, the main cell 30 the discharge percentage of either an anode or control cathode of the indicator cell 20 is approximately the same as the discharge percent of a control electrode of the main cell 30. To use the main cell 30 to an extraction of Extremely high or low current, that is to say, that deviates to a great extent from normal use, the percent of discharge of the indicator cell 20 will be a function of the discharge percent of the main cell, if it is not a linear function of the same .

The indicator cell 20 (Figure 2) is a miniature electrochemical cell containing a cathede material 43 and an anode material 47, which are desirably spaced from one another, and which can be in the same plane. The cathode 43 and the anode 47 are desirably electrochemically different active materials in contact with an electrolyte, which results in a cell having a finite electromotive force. Cathode 43 and anode 47 are thin coatings deposited on substrates 42 and 48, respectively. It is desirable that the material used for the cathode 43 and the cathode substrate 42 do not react in the atmosphere or be subject to corrosion. In the embodiment shown in Figure 2 a preferred cathode material 43 may be MnO_ lambda and a preferred anode material may be silver. The substrate of the anode 48 is preferably conductive and preferably carbon and the substrate of the cathode 42 is cenductor. (It is possible to use a material, non-conductive for the anode substrate 48, but a conductive conductor substrate is preferred (it will be described here). A conductive anode substrate 48 is used to prevent electrically insulated metal islands from appearing on the substrate when the anode 47 is stripped electrochemically from one end to the other, a further requirement is that the substrate of the an: d: 4 is of a color that provides a high contrast with the color of the anode 47, thus giving a highly discernible visual indication of the clearance of the anode 47. A preferred arrangement of cathode 43 and anode 47 in mutual relation and the underlying conductive substrate is shown in Figure 2. A space 44 separates the cathode 43 from the anode 47 and also separate the underlying conductive substrates 42 and 48, as best seen in Figure 2. Also, there is a film of insulating material 35 under the conductive substrates 42 and 48. The conductive substrate 42 (Figure 2) may extend beyond the edge 43 (b) of the superposed cathode material to form extended portions of the substrate 42 (a) . Similarly, the conductive substrate 48 can extend beyond the edge 47 (b) of the superposed anode material to form the extended substrate portion 48 (a). An adhesive is applied to the surface of the extended portions 42 (a) and 48 (a), thereby forming an adhesive boundary around the periphery of the conductive substrates 42 and 48. The adhesive boundary 55 defines a window space 53 on the cathode 43 and the anode 47. A clear electrolyte layer 45 is applied in the window space 53, so as to cover the cathode 43 and the anode 47. The end 48 (b) of the extended substrate portion 48 (a) protrudes from the anode side of the cell 20. Similarly the end 42 (b) of the extended substrate portion 42 (a) protrudes from the cathode side of the cell 20. Adheres a piece of aluminum foil 65 to the end of the anode substrate 48 (b) using conductive adhesive 62 placed therebetween. The blade 65 serves to convey current from the substrate 48 to the negative terminal of the battery 115 (Figure 2A). The end of the cathode substrate 42 (b) is covered on its upper surface with conductive adhesive 61. A transparent barrier film 52 is applied over the window 53 with the edges of the film in contact with the adhesive boundary 55. In this way , the barrier film 52 is a protective film that covers and hermetically seals the electrolyte 45. The barrier film 52 is held in place by the adhesive boundary 55. The indicator cell 20 can be secured to the armature of the main cell 30 with a pressure sensitive adhesive 32 applied to the underside of the condition indicator under the insulating film 35. The auxiliary cell 25 (Figure 2) is desirably a thin, flat energy cell. The auxiliary cell 25 has a thickness of less than 100 thousandths of an inch (2.5 mm), preferably a thickness of between about 2 and 100 thousandths of an inch (0.05 and 2.5 mm), more preferably a thickness of between about 2 and 15 thousandths of an inch (0.05 and 0.4 mm). The auxiliary cell 25 contains a coating of active material of the anode ", a coating of active material of the cathode 83, and an electrolyte layer 73 therebetween.The active material of the anode 77 can be coated or laminated to a conductive substrate 76. The active material of the anode 77 is in contact with the separator 72 filled with the electrolyte 73. The active material of the cathode 83 that can be coated or laminated to a conductive substrate 81 is also in contact with the electrolyte 73 contained within the separator 72. anode and cathode conductive substrates 78 and 81, respectively, can typically be aluminum foil or carbon coated metal.A conductive adhesive 92 can be applied to the underside of the auxiliary cell 25 in contact with the exposed surface. of the conductor substrate 81. The auxiliary cell 25 is electrically connected to the indicator cell 20 (Figure 2), electrically connected by the application of the the anode tongue 77 (a) of the auxiliary cell 25 so that they are in contact with the conductive adhesive 61 on the tongue of the substrate of the entire 42! b) of the indicator cell 20. This electrically connects the active material of the anode auxiliary 77 with the all 43 of the indicator cell 20 consistent with the circuit diagram of Figure 1. The connections to the main cell 30, typically a conventional alkaline cell, are illustrated with reference to Figures 2A. The active material of the oxidizing cathode 83 is electrically connected to the positive terminal 145 of the main cell 30 via the conductive adhesive 92 (FIG. 2), which connects the auxiliary cathode 83 to the housing of the main cell 83 as shown in FIG. shown in Figure 2A. The leaf tab 65 is pressed to come into permanent contact with the negative end cap 110 of the main cell (Figure 2A), so that the conductive adhesive 62 remains in contact with the end cap 110. Such connection places the anode 47 of the indicator cell 20 in electrical contact with the negative terminal 115 of the main cell 30. The condition indicator 10 can be integrated on the inner surface of the film label 58 for the main cell as illustrated in Figure 2A. Label 58 may desirably be a heat shrinkable film such as polyvinyl chloride or polypropylene. The condition indicator 10 can be formed on one side of the label by sequential printing or lamination of each of the coatings comprising the indicator cell 20 and the auxiliary cell 25. A layer of pressure-sensitive adhesive can be applied. heat to the internal surface of the label and the label with the integrated condition indicator can be applied to the main cell 30 by winding it around the cell housing. The ends of the label can then be thermally shrunk on the upper and lower flanges 152 and 154, respectively, in a conventional manner by subjecting the edges of the label to a sufficient heat to cause shrinkage. In operation, when the main cell 30 is discharged, the active material of the indicator anode 47 is discharged (rinsed). The active material of the anode 47 gradually disappears by the portion of the active anode layer near the cathode layer 43, namely the end 47 (a) (Figure 2). This provides a visually discernible fuel metering effect. The amount of indicator anode remaining in cell 20 at any time during the life of main cell 30 is easily visible through transparent electrolyte 45. This allows easy determination of the degree of discharge of the main cell by visual inspection through the window 53 of the amount of anode 47 remaining in the indicator cell 20. A calibrated graph scale adjacent the indicator anode 47 can be provided to make it easier to determine when the anode 47 has been sufficiently exhausted indicating that the cell Main 30 must be replaced. The following materials can be used to construct the condition indicator 10: The anode of the indicator cell 47 can be composed of a silver coating (with a thickness of between 500 and 1000 angstroms) deposited on the upper part of the anode substrate 48 by sublimation cathodic or by evaporation with electron beam. The anode substrate 43 and the anode substrate 42 of the indicator cell can be composed of a material filled with carbon (Velstat 3M), Materials Ine (CMI). Alternatively, the anode substrate 48 may be composed of an insulating plastic film such as the ACLAR (polychlorotrifluoroethylene) film of Allied Signal Co. or LODEX film (polyethylene naphthalate) from ICI Americas coated with an electronically conductive film such as the coating of indium tin oxide PITO) or conductive carbon. Alternatively, the substrate di -.-, anode 48 can be composed of an insulating material. The anode substrate 48 has a thickness, desirably, of between about 0.5 and 1 thousandth of an inch. The cathode of the indicator cell 43 is composed of a cathode mixture, for example, containing cathode active material such as 72 and MnO_ lambda. The cathodic mixture that contains the material V_0? or MnO. Lambda can be prepared by mixing such material with conductive particles, for example, carbon, graphite; metallic powder. The cathodic mixture can be mixed with a binder and a solvent such as celivinylidene fluoride and l-methyl-2-cirro! idinena to form a coatable ink. The ink can then be coated on the cathode substrate 42 as a wet film 0.2-2 mils thick and then dried to form the cathode. The electrolyte of the indicator cell 45 (Figure 2) can be prepared by first forming an electrolyte solution composed of a mixture of silver trifluoromethanesulfonylimide (AgTFSI), lithium trifluoromethanesulfonylimide (LiTFSI), dissolved in the solvent 3-metilsulfolano and then gelling the solution with poly (vinylidene fluoride). The electrolyte 45 can be prepared by mixing 8 parts by weight of electrolyte solution with 3 parts by weight of poly (vinylidene fluoride). The mixture is extruded at a temperature of about 140 ° C to the desired thickness, preferably between about 1 and 4 mils (0.025 mm and 0.10 mm) and applied to the anode 47 and the cathode 43 of the indicator cell. The applicator adhesive block 55 (Figure 2) can be selected from a wide range of pressure sensitive adhesives. A desirable adhesive is a conventional butyl rubber-based adhesive such as the polyisobutylene / isoprene copolymer adhesive available as Butyl 054 rubber adhesive from EXXON Co. Adhesive block 55 desirably has a thickness of between about 1 and 2.5 mils (0.025 mm and 0.0625 mm). The transparent barrier of the indicator 52 may be, desirably, composed of ACLAR, col? Clerotrifluoethylene (Allied Signal Co.) Film of a thickness of between about 0.6 and 1 thousandth of an inch (0.015 and 0.25 mm) or Kalodex film ( polyethylene naphthalate). The conductive adhesive 62 may desirably be a carbon-filled conductive adhesive such as that available under the trade designation of the AP.CLAD conductive transfer adhesive from Adhesives Research Co. The adhesive coating 62 may desirably be about 0.5. thousandths of an inch (0.012 mm) thick. The sheet support 65 may desirably be aluminum sheet of between about 0.25 and 0.5 mils (0.006 and 0.012 mm) thick. The materials used in the auxiliary cell 25 depend on the open circuit voltage of the indicator cell. The materials for the auxiliary cell 25 are selected so that the total open circuit voltage across the condition indicator assembly 10 as a whole is approximately the same as that of the main cell being discharged. Any aqueous or organic electrolyte may be used in the auxiliary cell 25. If an aqueous electrolyte is used, a cathode conductive substrate of the typical auxiliary cell 81 may be composed of poly (virile acetate) / poly (poly) acetate film. (vinyol chloride1 filled with carbon (Rexha Graphics conductive film, # 2664-01) As described above, the conductive layer 81 is laminated to an aluminum foil layer 82. The conductive polymeric film may desirably be be about 1 mil (0.025 mm) thick and the aluminum sheet between about 0.25 and 0.5 mil (0.006 and 0.012 mm) thick.The cathode of the auxiliary cell 83 is composed, desirably of a printed coating containing x% electrolyte manganese oxide (EMD), (90-X)% graphite and 10% polyvinyl chloride binder The active layer of the cathode 83 can be prepared by dispersing 3 parts by weight of a mixture of EMD and graphite in 7 parts by weight of crosslinked acrylic acid copolymer Carbopol 940 (BF Goodrich Co.) at 0.75% aqueous and adjusting the mixture to a pH of 10 with KOH and then adding PVC latex HALOFLEX 320 (ICI Americas - EU Resins Division) in a sufficient amount comprising 10% by weight of material of final dry cathode. The mixture is then coated as a wet film (0.2 to 0.5 mil thick) on the polymer layer filled with carbon 81 and then air dried to form the dry active layer of the cathode, 83. The separator the auxiliary cell 72 may be a porous membrane of nitrocellulose or cellophane of approximately 1 mil thickness (0.025 mm) containing approximately 2-3 microliters of an electrolyte solution 73 composed of approximately 24 to 32 wt% of adjusted aqueous ZnCl. at a pH of 4 by the addition of ZnO. A seal 85 is provided between the outer edges of the anode 77 and the cathode 83 to hold the auxiliary cell together and prevent contaminants from entering the cell. The seal 85 can be suitably formed of a polyvinyl acetate / thermally sealable polyvinyl chloride film. Alternatively, may be composed of a pressure sensitive adhesive of butyl rubber such as Butyl 065 rubber from Exxon Co. The seal 85 is advantageously between about 1 and 2 mils (0.022 mm and 0.05 mm) thick . The anode material of the auxiliary cell 77 can be coated on a substrate 76 composed of poly (vinyl acetate) / poly (vinyol chloride) film, filled with carbon, conductive (conductive plastic film of Rexham Graphics No. 2664- 01). The substrate 76 may be laminated to an aluminum foil layer (not shown) on the surface of the substrate 76 opposite the anode material 77. The conductive polymeric p-liquor may desirably be about 1 mil. (0.025 mm) thick and the aluminum sheet between approximately 0.25 and 2.5 thousandths of an inch (0.CC6 and 0.012 mm.) Thick. TheThe anode of the auxiliary cell 77 can be a coating composed of 90% anodic powder (for example, zinc powder or other metallic powder depending on the necessary voltage) and 10% styrene-butadiene copolymer binder (SBR). . The anchor layer 77 can be prepared by first distributing 6.5 parts by weight of zinc powder (with a particle size of 5 to 7 microns) in 3.5 parts by weight of crosslinked acrylic acid copolymer gel Carbopol 940 at 1.25% aqueous (adjusted to a pH of 12 with KOH). A styrene-butadiene rubber latex (latex SBR ROVENE 5550 from Rohm &Haas Co.) is then added in an amount sufficient to give 1 part by weight of styrene-butadiene rubber per 9 parts of zinc in the dry film. final. The mixture is then coated as a wet film (0.5 to 1.5 thousandths of an inch thick) onto the polymeric layer filled with carbon 76 and then air dried. The contact adhesive of the auxiliary cell 61 and 92 can be selected from a variety of conductive adhesives. A suitable adhesive 61 or 92 can be a conductive carbon-filled transfer adhesive, available as an ARCLAD adhesive from Adhesives Research Co. Such an adhesive can be coated to a thickness of approximately 0.5 mils (0.012 mm) on a layer of aluminum foil 32 forming the adhesive layer 92. The same adhesive composition can be coated to a thickness of approximately 0.5 mils (0.012). mm) forming the adhesive layer 61 on the end of the indicator cathode substrate 42 (b). The indicator support adhesive 32 can be selected from a wide variety of pressure sensitive adhesives. Desirable adhesive 32 is comprised of a butyl rubber pressure sensitive adhesive such as Butyl 065 rubber from Exxon Co. The following are examples of the tester described with reference to Figure 2.

Example 1 Indicator constructions of the working condition 10 of the type described in the preferred embodiment (Figure 2) were constructed to indicate the load status of conventional AA alkaline cells of Zn / MnO.- (1.5 volts) discharged through various loads. The indicator cells 20 as described with reference to Figure 2 were prepared with the following components: The anode of the indicator cell 47 was prepared by sputtering by depositing 66 angstroms of silver on the substrates filled with carbon, conductors, 48 (polyethylene filled with Velstat carbon from 3M Company). The area of. anode is approximately 0.86 inches (2.2 cm) by 0.2 inches (0.51 cm). The cathode of the indicator cell 43 was formed first by preparing a cathode mixture of V205 and graphite 70:30 (by weight). Next, 3 gm of this mixture of V205 and graphite were mixed with 0.45 g of polyvinylidene fluoride (PVDF) and 4.5 g of l-methyl-2-pyrrolidinone to form an ink. The ink was coated on the substrate 42 (polyethylene filled with VELSTAT carbon) and dried at 150 ° C for 1 hr in air to form a 1-mil thick film cathodic coating. The cathode area is approximately 0.2 inches (0.51 cm) by 0.2 inches (0.51 cm). The cathode was separated from the anode by a space of approximately 0.05 inch (0.13 cm) inside a 2.5 mm thick (0.06 mm) butyl rubber pressure-sensitive adhesive window having an interior space of approximately 0.7 inches long by 0.30 inches wide. The anode and the cathode were contacted by means of a transparent electrolyte 2 mils thick 45 approximately 0.61 inches long by approximately 0.2 inches wide consisting of LiTFSI (lithium trifluoromethanesulfonylimide) 0.5 M and AgTFSI (trifluoromethanesulfonylimide) silver) 0.003M in solvent and was prepared as described above for the preferred embodiment. A transparent 1 mil polyethylene naphthalate KOLODEX barrier film of about 1 inch in length by 0.60 inches wide was used to seal the indicator. The finished indicators are between approximately 6 and 7 thousandths of an inch (0.15 and 0.13 mm) thick. Auxiliary cells 25 of the type described with reference to Figure 2 were prepared with the following components. The cathode of the auxiliary cell 83 was prepared by coating a layer of manganese dioxide containing electrolyte manganese dioxide (EMD) on a conductive substrate 81 composed of a plastic film filled with carbon, conductive no. 2664-01 of Rexham Graphics as described above. The manganese dioxide coating was applied as a 0.5 mil thick film having a dry composition that is 68% EMD and 17% graphite. The anode of the auxiliary cell 77 was prepared by applying a zinc coating on the plastic substrate filled with carbon, conductor no. 2664-01 of Rexham Graphics as described in the preceding description. The dry zinc anode has a thickness of approximately 1 mil and an area of approximately 0.070"(0.45 emp to give a capacity that exceeds several times that of the cathode.) Separator 72 was prepared using a 1-mil cellophane film. inch thick that contained approximately 6 x 10"'electrolyte liters of pH 4 (28% ZnCl2). Seal 85 is a pressure sensitive adhesive of 2 mil rubber butyl rubber (rubber adhesive Exilon Butyl 065) used to seal the auxiliary cell The finished auxiliary cells are approximately 8 mils thick and had an AC resistance measured at 1 kHz of approximately 2 k-ohm. The indicator and auxiliary cells are connected together in series to form a condition indicator assembly 10 as shown in Figure 2. The complete condition indicator 10 in this example has a thickness of between approx. between 6 and 8 thousandths of an inch (0.15 and 0.2 mm). The condition injector 10 is connected in parallel as shown in Figures 1 and 2A) to the terminals of an AA alkaline cell (1.5 volts) of recent Zn / Mn02 using the conductive 0.5 mil thick adhesive.

ARCLAD (61 and 92) as described above. The indicator cell 20 has a positive electromotive force (f.e.m.) The open circuit assembly through the condition indicator assembly 10 as a whole is approximately the same as that of the discharged main cell. The AA cells are discharged from 1.5 to 0.8 volts through load resistors either 1 ohm, 4 ohm, 36 ohm or 75 ohm, either continuously or intermittently and the current through the indicator cell 20 is approximately ( 0.5-2) x 10"" amps. In all cases the indicator anode is rinsed in a manner similar to a measuring device to visually reveal the substrate of the underlying black conductive anode 48, with clearance starting from the end 47 (a) closest to the cathode and proceeding to the extreme opposite of the cathode. The amount of clearance correlates proportionally with the degree of discharge of cell AA. In this way, the tester serves as an indicator of effective charge status for the main cell. The specific condition indicator assembly described in this example can be advantageously employed to test the condition of a conventional Zn / Mn02 alkaline cell that can typically operate with a load resistance of between about 1 and 1,000 ohms. The application of the invention, however, is not intended to be limited to alkaline cells, but can be effectively used to test the condition of any dry cell.

Example 2 Indicator cells 20 were prepared in a manner similar to that described in Example 1, except that the cathode mixture of V; 0; it was replaced with a different cathode mix containing lambda Mn02. First a cathode ink was prepared by mixing 3 g of a mixture of LiMn204 and graphite (70:30 by weight), 0.45 g of polyvinylidene fluoride (PVDF) and 4.5 g of n-methylpyrrolidinone (NMP). The cathodic ink was coated on the substrate 42 (VELSTAT material) and dried at 150 ° C in air for 1 hr. The LiMn204 contained in the dry ink was converted to Mn02 lambda by leaching the dry ink onto the substrate in 0.03M H2SO4 for 30 minutes. After leaching with acid, the cathodes were rinsed and air dried for 1 hr. The indicator cell 20 was assembled in the same manner described in Example 1 but using the cathode described above. The switch cell 20 of this example has an open circuit voltage of approximately 0.5 volts. Auxiliary cells were prepared in the same manner as described in Example 1, except that a Pb anode was used. The Pb anode can be prepared in the same manner as the Zn anode, except that Pb powder was used instead of Zn. The electrolyte used is 28% ZnCl2, pH 4, saturated with PbCl2. The auxiliary cell prepared in this way has an open circuit voltage of (VCA) of about 1.05 volts. The indicator cell and the auxiliary cell were connected in series with each other as in Example 1 to form the condition indicator assembly 10 connected to an alkaline cell AA (1.5V) of recent Zn / MnO. The open circuit voltage across condition indicator assembly 10 is approximately the same as that of cell AA. During the discharge of the AA cell, the condition indicator behaves in a manner similar to that of Example 1. In all cases, the indicator anode is rinsed in the form of a measuring device to visually reveal the underlying black conductive substrate 48, with clearance starting from end 47 (a) closest to the cathode and proceeding to the opposite end of the anode. The amount of clearance correlates proportionally with the degree of discharge of cell AA. In this way, the assembly serves as an indicator of the effective state of charge for the main cell. Although the present invention has been described with reference to specific modalities and specific construction materials, it should be appreciated that other embodiments and materials are possible without departing from the concept of the invention. Therefore, the invention is not intended to be limited to the specific embodiments described herein, but the scope of the invention is defined by the claims and equivalents thereof.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers. Having described the invention as above, property is claimed as contained in the following:

Claims (10)

1. The combination of a battery and a battery condition indicator assembly to determine the state of charge of the battery; characterized in that the battery comprises an armature, a negative terminal and a positive terminal, and the condition indicator assembly is integrated to the label attached to the battery; wherein the indicator assembly comprises an indicator cell comprising an anode, a cathode and an electrolyte, the electrolyte is in electrical contact with at least a portion of both the anode and the cathode of the indicator cell, wherein the indicator cell contains a force electromotive (fem) itself and at least a portion of the anode and the cathode of the indicator cell is visible; wherein the condition indicator assembly further comprises an auxiliary cell which is an electrochemical energy generating cell comprising an anode, a cathode and an electrolyte in contact with at least a portion of the anode and the cathode of the auxiliary cell, wherein one of the anode and the cathode of the auxiliary cell are electrically connected to one of the anode and the cathode of the indicator cell; wherein the remaining electrode of the auxiliary cell and the remaining electrode of the indicator cell are electrically connected in parallel to the terminals of the battery; and wherein during the discharge of the battery the reaction begins at the visible electrode of the indicator cell and continues to the remote regions thereof.

2. The combination according to claim 1, characterized in that the cell condition indicator assembly has a thickness between approximately 2 and 100 thousandths of an inch (0.05 and 2.5 mm).

3. The combination according to claim 1, characterized in that the anode and the cathode of the indicator cell comprise different electrochemically active materials.

4. The combination according to claim 1, characterized in that the anode and the cathode of the indicator cell are laterally separated, so that no portion of the anode of the indicator cell overlaps any portion of the cathode of the electrolytic cell.

5. The combination according to claim 1, characterized in that the anode of the indicator cell comprises silver.

6. The combination according to claim 5, characterized in that the cathode of the indicator cell comprises V205.

7. The combination according to claim 5, characterized in that the cathode of the indicator cell comprises Mn02 lambda.

8. The combination according to claim 5, characterized in that the electrolyte of the indicator cell comprises lithium trifluoromethanesulfonylimide and silver trifluoromethanesulfonylimide.

9. The combination according to claim 1, characterized in that the anode of the auxiliary cell comprises zinc and the cathode of the auxiliary cell comprises manganese dioxide.

10. The combination according to claim 1, characterized in that the anode of the auxiliary cell comprises lead and the cathode of the auxiliary cell comprises manganese dioxide.