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`U8005371454A
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`[191
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`[11] Patent Number:
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`5,371,454
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`United States Patent
`Marek
`[45] Date of Patent: Dec. 6, 1994
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`
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`[54] PASSIVE BATTERY CHARGING SYSTEM
`
`Attorney, Agent, or Firm—Michael A. O’Neil
`
`[76]
`
`Inventor: Albert Marek, 705 Bradley Cir.,
`Grand Prairie, Tex. 75051
`
`[21] Appl. No.: 27,406
`
`[22] Filed:
`
`Mar. 8, 1993
`
`[51]
`Int. Cl.5 ................................ H02J 7/10
`
`[52] U.S. Cl. .......................................... 320/15; 320/2;
`320/57
`[58] Field of Search .......................... 320/15, 17, 57, 2
`[56]
`References Cited
`U.S. PATENT DOCUMENTS
`
`3,579,075 5/197! Floyd ......
`
`4,092,580 5/ 1978 Prinze .....
`..
`4,575,670 3/1986 Hignutt
`4,831,321
`5/1989 Cooper ............................... 320/2 X
`
`OTHER PUBLICATIONS
`
`“Dual Pro Charger”, Charging Systems International,
`Advertising Letter and flossy flyer Jan., 1991.
`“Keep Car and Boat Batteries Charged When Not in
`Use—Safety”, Herrington Catalog, Valentine Ed., p.
`172 1993.
`
`[57]
`
`ABSTRACT
`
`A battery charger for simultaneously slow charging and
`thereafter maintaining a charge in a plurality of plate-
`type batteries includes a first transformer connected
`through a circuit loop to a first battery wherein the
`circuit loop includes a rectifier, and a current limiter
`and visual indicator of the charge level of the battery. A
`second transformer is connected through another cir-
`cuit loop to one battery and through a third circuit loop
`to a second battery. The circuit loop of the first trans-
`former may be connected to a first battery with one of
`the circuit loops of the second transformer being con-
`nected to a second battery connected in series to the
`first battery thus allowing the two loops to remain iso—
`lated from each other and allow for charging of the
`series connected batteries without removal of the series
`connection. In a second embodiment of the invention, a
`switch is connected in the loop to bypass the current
`limiter to allow a fast charge condition. A small indica-
`tor light is connected to the switch to indicate a fast
`charge condition. Thus, the charger may be switched
`from a slow passive charge condition to a fast charge
`condition, and back to a slow charge condition.
`
`Primary Examiner—Robert J. Hickey
`
`14 Claims, 5 Drawing Sheets
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`APPLE 1007
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`US. Patent
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`Dec. 6, 1994
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`US. Patent
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`Dec. 6, 1994
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`Sheet 5 of 5
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`1
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`5,371,454
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`PASSIVE BATTERY CHARGING SYSTEM
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`TECHNICAL FIELD
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`This invention relates to battery chargers, and in 5
`particular, to a system for charging and maintaining
`charge in an infrequently used battery.
`BACKGROUND OF THE INVENTION
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`15
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`30
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`Batteries in seasonal vehicles such as boats, farm 10
`equipment, RVs, in some military equipment, antique
`cars, and other vehicles used infrequently or only sea-
`sonally tend to lose their charge, requiring recharging
`at various use intervals. Conventional fast battery char-
`gers are large and cumbersome, use a substantial
`amount of electricity, and charge at a faster rate than
`the battery can accept. When being charged with a
`conventional fast charger, the voltage and amperage of
`the battery will typically rise at a faster rate than the
`battery potential. Thus, when the voltage and amperage 20
`reach a level indicating that the battery is fully charged,
`the battery charger will be disconnected or turned off.
`The battery will then begin to equalize the voltage,
`amperage and potential, with the voltage and amperage
`levels dropping and the potential increasing until equal- 25
`ization is reached. Because of the variation in the volt-
`age, amperage, and potential levels at the time full
`charge is indicated, the battery will actually be charged
`to only about 80% of its capacity following equaliza-
`tion. Thus, the prior art fast chargers cannot charge a
`battery to 100% of its capacity.
`Batteries repeatedly charged in this fashion'reduces
`the capacity of the battery such that the battery will
`begin to lose the ability to accept a full 100% charge of
`the original capacity. Additionally, the use of a fast 35
`battery charger often causes rapid expansion of the
`battery fluid and the generation of gases, thus requiring
`the removal of the battery caps while charging the
`battery. Failure to remove the caps may result in explo-
`sion of the caps causing damage or total destruction of 40
`the battery. Thus, marine, recreational vehicle, and
`other infrequently used batteries are protected under
`substantially shorter warranty periods, often less than
`one-half the length of the warranty periods for regu-
`larly used batteries, such as car batteries.
`Trickle chargers, another conventional type battery
`charger, are slow battery chargers, charging the battery
`with only oneto-three amps of charge at a time. A slow
`charge will bring the battery to full charge and allevi-
`ates having to remove the battery caps while charging. 50
`However, if left on the battery for an extended length of
`time after the battery has obtained full charge,
`the
`trickle charger will damage the battery and may de-
`stroy it completely.
`Due to the slow rate at which the trickle charger
`charges the battery, the charger must be connected to
`the battery a substantial period of time prior to the use
`of the boat or vehicle, prohibiting spontaneous use
`thereof.
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`45
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`In one attempt to overcome the foregoing problems,
`fast and slow battery chargers were designed to include
`built in features for automatic turn off of the charger
`once the voltage of the battery indicated a full charge.
`In such chargers, once the voltage drops to a predeter-
`mined level, the charger is automatically turned back on
`to again recharge the battery until the voltage reaches
`the full charge level. Although the battery is automati-
`cally recharged, this cycling process reduces the life of
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`the battery. Depending upon the cycling range of the
`particular charger, the user may decide to use the vehi-
`cle at a point where the voltage of the battery has
`dropped to a level where the charger is about to begin
`recharging the battery.
`Many fishing boats have a driving battery and two
`12-volt batteries connected as a 24—volt power source
`for operation of a trolling motor. Thus, three chargers
`were required for charging each of the three batteries
`simultaneously.
`SUMMARY OF THE INVENTION
`
`The passive battery charger of the present invention
`overcomes the foregoing and other problems associated
`with prior art battery chargers by utilizing a continuous
`slow charge process, along with the capability of charg-
`ing multiple batteries at the same time. A first embodi—
`ment battery charger includes at least two lZ-volt trans-
`formers each connected in a circuit to at least one posi-
`tive and one negative battery cable or terminal, with a
`light bulb connected in the circuit to regulate the am-
`perage of the charging current flowing from the trans-
`former to the battery. The light bulb further visually
`indicates the status of the charge on the battery in that
`the brightness of the light is inversely proportional to
`the battery charge. The circuit is further configured to
`prevent sparks when the charger is hooked up to the
`battery in reverse position or when the cables acciden-
`tally come into contact with one another. When the
`cables are connected in reverse position to the battery,
`the light bulb in the circuit is brightly illuminated. On
`the other hand, the bulb is dimly illuminated when the
`cables are properly connected to the battery.
`The flow of current in the circuit from the trans-
`former is reduced as the resistance of the battery in-
`creases with the increased charge. As the battery
`reaches a full charge, the resistance of the battery is
`balanced with a maximum output of the transformer.
`The light bulb in the circuit line regulates the amperage
`of current flowing from the transformer to the battery
`as it is charged. The light bulb further allows for the
`back down of current produced by the transformer as a
`result of the increased resistance from the battery dur-
`ing charging. Thus, the charger may remain continu-
`ously connected to the battery without reducing the life
`of the battery through cycling or overcharging, and
`without damage to the transformer. Due to the low
`amperage charging process, the battery charger uses
`very little electricity, resulting in very low operational
`costs.
`
`In fishing boats wherein the trolling motor is pow-
`ered by two 12-volt batteries connected in series to
`provide 24-volts, the battery charger of the present
`invention allows each 12-volt battery in the 12/24-volt
`configuration to be charged at the same time without
`removing the series connection between the two batter-
`ies. By providing at least two transformers, there is
`capacity for charging the driving battery for the boat at
`the same time as the trolling batteries. One transformer
`is connected through a split circuit to two sets of bat-
`tery cables. The set of cables is connected to the driving
`battery with the second set of cables connected to one
`of the 12-volt trolling batteries. The remaining 12-volt
`trolling battery is connected to the cables from the
`second transformer. Thus, the circuits for charging the
`series connected batteries are isolated from one another
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`to allow charging operations without requiring removal
`of the series connection.
`In the event a battery must be charged in a relatively
`short period of time, in a second embodiment of the
`invention, a manual switch is connected to bypass the
`light bulb in the circuit, thereby allowing the flow of
`higher voltage and amperage to the battery for a fast
`charge. An indicator light is connected to the switch to
`indicate a fast charge condition, When the switch is in
`the off position, the passive slow charge condition re-
`sumes to maintain charge. Thus, in addition to the low
`operational costs and the continuous low amperage
`multiple battery charging capabilities, the charger may
`be converted to a fast charge device for charging of the
`battery in a few hours.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`For a more complete understanding of the present
`invention and the advantages thereof, reference is now
`made to the following Detailed Description taken in
`conjunction with the accompanying Drawings in
`which:
`
`FIG. 1 is an electrical schematic of a battery charger
`incorporating a first embodiment passive battery char-
`ger of the present invention;
`FIG. 2 is a drawing showing an obtuse view of the
`housing, and cables of the battery charger of FIG. 1;
`FIG. 3 is a drawing similar to FIG. 2 with the top half
`of the housing removed to show the interior of the
`battery charger of FIG. 1;
`FIG. 4 is a side view of the battery charger of FIG. 3;
`FIG. 5 is a drawing of the circuit board showing the
`wiring connections for the battery charger of FIG. 1;
`FIG. 6 is a rear view of the housing of FIG. 1;
`FIG. 7 is a top view of a boat, illustrating the posi-
`tioning of and the charging of the trolling motor and
`driving motor batteries;
`FIG. 8 is an obtuse view of a mounting bracket for
`mounting the battery charger to a receiving surface;
`FIG. 9 is a schematic circuit diagram for a battery
`charger incorporating a second embodiment ofthepres-
`ent invention;
`FIG. 10 is an obtuse View of the housing of the bat-
`tery charger of FIG. 9;
`FIG. 11 is a view similar to FIG. 10 with the top of
`the housing removed to show the interior of the battery
`charger of FIG. 9; and
`FIG. 12 is a side view of the battery charger of FIG.
`11.
`
`DETAILED DESCRIPTION
`
`Referring now to the Drawings and more particu-
`larly to FIG. 1 thereof, there is shown a schematic
`diagram of the electrical circuit of a battery charger 10
`incorporating a first embodiment passive battery char-
`ger of the present invention for charging 12-volt, acid
`or jell, regular or deep, cycle batteries. As illustrated in
`FIG. 1, the battery charger 10 is equipped with a con-
`ventional AC plug 12 insertable into a 120-volt AC
`receptacle and having opposite prongs 14 and 16 and a
`ground prong 18. The opposite AC prongs 14 and 16
`are connected to the opposite ends of the primary coil
`20 of a first transformer 22, and to the opposite ends of
`the primary coil 24 of a second transformer 26. The first
`transformer 22 is preferably a conventional 12-volt/3
`amp transformer. The top of the secondary coil 28 of
`first transformer 22 is connected through line 30 to the
`anode of rectifier diode 32, the cathode of which is
`
`4
`connected to a battery cable 34, in turn selectively con-
`nected at its distal end to the positive post of a lZ-volt
`battery 36. The negative post of battery 36 is selectively
`connected through a battery cable 38 to the anode of
`rectifier diode 40, the cathode of which is connected to
`a one and one-half amp light bulb 42, which functions as
`a current limiter in the circuit 44. Although in the pre-
`ferred embodiment of the invention the current in the
`circuit is limited by the one and one-half amp light bulb,
`other conventional current limiters may be used in place
`thereof. To complete the circuit, light bulb 42 is con-
`nected through line 46 to the bottom of secondary coil
`28.
`When charging a second battery 48, the current from
`transformer 22 is split between the first circuit 44 and a
`second circuit 50. The top side of the secondary coil 28
`is connected through line 30 to the anode of diode 52,
`the cathode end of which being selectively connected
`to the positive post of the battery 48 through a battery
`cable 54. The negative post of the battery 48 is selec-
`tively connected through a battery cable 56 to the
`anode of a diode 58, the cathode end of which is con-
`nected to a second one and one-half amp light bulb 60,
`functioning as a current limiter for the second circuit 50.
`To complete the circuit 50, the light bulb 60 is con-
`nected to the bottom of the secondary coil 28 of first
`transformer 22 through lines 62 and 46.
`As further illustrated in FIG. 1, the second trans-
`former 26 is a conventional
`lZ-volt/ 1.5 amp trans-
`former, having a primary coil 24 and a secondary coil
`64. The top of secondary coil 64 is connected through
`line 66 to the anode of a diode 68, with the cathode end
`selectively connected through battery cable 70 to the
`positive post of a third 12-volt battery 72, which may be
`a single battery or may be tied in series to battery 48 as
`illustrated by dotted line 49 to provide a 24-volt battery.
`The negative post of the battery 72 is selectively con-
`nected through battery cable 74 to the anode of a diode
`76, the cathode end of which is connected to a third one
`and one-half amp light bulb 78, thereby limiting the
`current flowing through the circuit 80 to the battery 72
`to a maximum of one and one-half amps. To complete
`the circuit 80, the light bulb 78 is connected through
`line 82 to the bottom of the secondary coil 64 of the
`transformer 26. When charging a single battery or three
`separate batteries, any one or combination of the cir-
`cuits 44, 50, or 80 may be used.
`Referring now to FIGS. 2, 3, and 4, the transformers
`22 and 26 along with the components of circuits 44, 50
`and 80 are mounted within a housing 90, having a first
`half 92 and second half 94. The first half 92 defines a top
`96, a first side 98, and a second side 100. The second half
`forms a bottom 102, a third side 104, and a fourth side
`106. In the first and second sides 98 and 100, respec—
`tively, are vents 108 to allow air circulation through the
`battery charger 10. In the third side 104 are windows
`110 for observing the illumination of the light bulbs 42,
`60, and 78. The first half 92 of the housing is attached to
`the second half 94 of the housing using conventional
`fasteners 112.
`
`Referring now to FIGS. 2, 3, and 6, battery cables 70
`and 74 from circuit 80 and battery cables 54 and 56 from
`circuit 50 exit the housing 90 through opening 120 in the
`fourth side 106 of the housing 90. Battery cables 70 and
`74 are paired with battery cables 54 and 56 to facilitate
`connection of the two pairs of cables to a pair of 12-volt
`batteries cross-connected for generation of 24-volts.
`Battery cables 34 and 38 from circuit 44 pass through
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`opening 122 in the fourth side 106 of the housing 90.
`The cord 124 for the conventional AC plug 12 exits the
`housing 90 through an opening 126 in the fourth side
`106 of the housing 90.
`Referring now to FIGS. 3 and 4, the light bulbs 42,
`60, and 78, are mounted in a circuit board 130 extending
`parallel to the third side 104 of the housing 90. The base
`132 of each of the bulbs 42, 60 and 78, is secured in the
`circuit board 130 with a rubber grommet 134. Each of
`the windows 110 in the third side 104 of the housing 90
`has a rubber grommet 136 positioned therein for con-
`tacting the lamp 138 of each of the bulbs 42, 60, and 78.
`As illustrated in FIG. 5, in addition to supporting the
`base 132 of each of the light bulbs 42, 60, and 78, the
`circuit board 130 provides the surface through which
`the connections 140 between the diodes 32, 40, 52, 58,
`68, and 76 and the battery cables 34, 38, 54, 56, 70, and
`74, respectively, and the connections 142 between the
`diodes 32, 52, and 68 and the lines 30 and 66 from the
`transformers 22 and 26.
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`6
`power for starting the gas engine 162 of the boat 150.
`The batteries 152, 154, and 160 are typically positioned
`as illustrated in FIG. 7, although any number of config-
`urations may exist due to the design of the particular
`boat 150. Battery cables 34 and 38 of the battery charger
`10 are connected to the driving battery 160. Cables 70
`and 74 are connected to either trolling battery 154, or
`152 and cables 54 and 56 connected to the remaining
`trolling battery. There is also a series connection 49
`between batteries 152 and 154. For convenience, the
`passive battery charger 10 may be permanently
`mounted in the boat 150 using two of the mounting
`brackets 164 as shown in FIG. 8, and remain continu-
`ously connected to batteries 152, 154, and 160, at all
`times. A flange 163 of each bracket 164 is inserted into
`the lower vent slot 230 of sides 218 and 220 of the hous-
`ing 90 and is attached to the receiving surface of the
`boat 150 with conventional fasteners by placing the
`fasteners through an opening 166 in each bracket 164.
`Referring now to FIG. 9, there is shown a battery
`charger 170 incorporating a second embodiment of the
`passive battery charger of the present invention. As
`illustrated in FIG. 9, the battery charger 170 is equipped
`with a conventional AC plug 172 insertable into a 120-
`volt AC receptacle, with opposite prongs 174 and 176
`and a ground prong 178. The opposite AC prongs 174
`and 176 are connected to the opposite ends of the pri—
`mary coil 180 of a transformer 182, having a secondary
`coil 184. The top of the secondary coil 184 is connected
`through line 186 to the anode of a rectifier diode 188,
`the cathode of which is selectively connected through a
`battery cable 190 to the positive post of a 12-volt battery
`192. The negative post of the battery 192 is selectively
`connected through a battery cable 194 to the anode of a
`diode 196, the cathode end of which is connected to a
`1.5 amp light bulb 198, functioning as a current limiter
`for the circuit 200. The passive battery charger 170
`operates in the same way as previously described with
`respect to the circuits 44, 50, or 80 of the first embodi-
`ment passive battery charger 10. The battery charger
`170 is, however, capable of producing a fast charge
`through the use of a double pole, double throw, switch
`202 which functions to bypass the current limiting bulb
`198. When in the closed position, the switch 202 creates
`a loop in the circuit bypassing the bulb 198, and closes
`the circuit such that a small indicator light 204 con-
`nected between the switch and line 186 is illuminated to
`indicate that the battery charger 170 is operating in a
`fast charge condition. It is understood that although the
`switch 202 is shown connected to a single circuit 200 in
`the charger 170, the switch may be connected to multi-
`ple circuits, such as those of the first embodiment bat-
`tery charger 10. Likewise, each of the circuits of the
`first embodiment battery charger 10 may be separately
`equipped with switches 202 such that any one or more
`of the driving motor battery or trolling motor battery
`may simultaneously receive a slow charge while the
`remaining battery or batteries receive a fast charge from
`a single charging unit 10.
`Referring now to FIGS. 10, 11, and 12, the trans-
`former 182 is mounted within a housing 210 having a
`first half 212 and a second half 214. The first half 212
`forms a top 216, a first side 218, and a second side 220.
`The second half forms a bottom 222, a third side 224,
`and a fourth side 226. The first half 212 is connected to
`the second half 214 with conventional fasteners 228
`along the first side 218 and second side 220. The first
`side 218 and second side 220 have vents 230 therein to
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`When charging a battery using the charger 10 of the
`present invention, the current limiting light bulb 42 in
`each circuit 44, for example, limits the current delivered
`to the battery 36 to a maximum of 1.5 amps, that being
`the maximum amps the bulb 42 is capable of pulling. As
`the charge on the battery 36 increases, the voltage and
`amperage delivered by the transformer 22 are repelled
`by the increasing charge on the battery 36, thereby
`reducing the amps of the current passing through the
`bulb 42. Thus, as the charge on the battery 36 ap-
`proaches 100% and the amps flowing through the bulb
`decrease, the illumination of the bulb 42 dims, thereby
`providing a visual indication at all times of the charge
`on the battery.
`The light bulb 42 prevents damage to the battery 36
`or transformer 22 by limiting the current flow to 1.5
`amps in the event of a reversed polarity attachment of
`the cables 34 and 38 to the battery 36, in which case the
`bulb 42 is brightly illuminated. Similarly, the light bulb
`in each of the circuits 44 and 50 limits the current
`through each circuit, such that a short in any one of the
`circuits or the connection of a dead battery to any one
`of the circuits will not interfere with the current flow-
`ing through the remaining circuit. The configuration of
`the circuits 44, 50, and 80 further prevents sparking 45
`when connecting the cables 34 and 38, 54 and 56, and 70
`and 74 to the batteries 36, 48, and 72, respectively.
`In the event batteries 48 and 72 are connected in
`series as shown at 49 for generation of 24-volts, the
`isolation of circuits 50 and 80 from one another allows
`batteries 48 and 72 to be charged simultaneously with-
`out removing the series connection 49. Pairing of the
`cables 54 and 56 of circuit 50 and the cables 70 and 74 of
`the circuit 80 as they exit the housing 90 facilitates
`proper connection to the paired batteries 48 and 72. The
`passing of cables 34 and 38 through a separate opening
`in the housing 90 reduces the possibility of connecting
`both sets of cables receiving power from a single trans-
`former 22 to the paired batteries 48 and 72, thereby
`facilitating the isolation of the circuits charging the
`paired batteries 48 and 72. By splitting circuits 50 and 44
`from a single transformer 22, the passive charger 10 is
`kept small and relatively light weight.
`Referring now to FIG. 7, there is shown a top view of
`a fishing boat 150. Most fishing boats 150 are equipped
`with two 12—volt batteries 152 and 154, to provide the
`power through a line 156 for driving a trolling motor
`158, as well as a 12-volt battery 160 for providing the
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`allow circulation of air through the charger 170. A
`window 232 in the third side 224 allows the illumination
`of the bulb 198 to be observed there through. Mounted
`on the third side 224 of the housing 210 is a lever 234 for
`actuating the switch 202. Also mounted on the third
`side 224 of the housing 210 is the small indicator light
`204 for indicating a fast charge condition when illumi-
`nated. The cord 236 of the conventional AC plug 172
`exits the housing 210 through an opening 238 in the
`fourth side 226. A second opening 240 in the side 226
`provides an exit for the battery cables 190 and 194 from x
`the housing 210.
`Referring now to FIGS. 11 and 12; the base 250 of the
`bulb 198 is mounted in a circuit board 252 and secured
`therein by a rubber grommet 254. The circuit board 252
`extends parallel to the third side 224. A second grom-
`met 256 is placed within the window 232 for contacting
`the lamp 258 of the bulb 198.
`I claim:
`
`1. Apparatus for simultaneous passive charging and
`thereafter maintaining of charge in a plurality of plate-
`type batteries, each having a known theoretical voltage,
`a positive terminal, and a negative terminal, comprising:
`a first power supply having an alternating current
`output;
`a first rectifier diode having an input electrically
`connected to said output of the first power supply
`and having an output electrically connected to the
`positive terminal of a first battery to be charged;
`a second rectifier diode having an input electrically
`connected to the negative terminal of the first bat-
`tery and an output;
`first current limiting means having an input electri-
`cally connected to the output of the second recti-
`fier diode and having an output electrically con-
`nected to the first power supply;
`a second power supply having an alternating current
`output;
`a third rectifier diode having an input electrically
`connected to said output of the second power sup-
`ply and having an output electrically connected to
`the positive terminal of a second battery to be
`charged;
`a fourth rectifier diode having an input electrically
`connected to the negative terminal of the second
`battery and an output;
`second current limiting means having an input electri-
`cally connected to the output of the fourth rectifier
`diode and having an output electrically connected
`to the second power supply;
`a fifth rectifier diode having an input electrically
`connected to said output of the second power sup-
`ply and having an output electrically connected to
`the positive terminal of a third battery to be
`charged;
`a sixth rectifier diode having an input electrically
`connected to the negative terminal of the third
`battery and an output; and
`third current limiting means having an input electri-
`cally connected to the output of the sixth rectifier
`diode and having an output electrically connected
`to the second power supply.
`2. The battery charging apparatus of claim 1, wherein
`the first alternating current power supply comprises a
`transformer capable of emitting a flow of electricity
`having a maximum voltage substantially equal to the
`theoretical voltageof the battery to be charged and a
`
`8
`maximum amperage substantially equal to the maximum
`amperage of the first current limiting means.
`3. The battery charging apparatus of claim 1, wherein
`the second alternating current power supply comprises
`a transformer capable of emitting a flow of electricity
`having a voltage substantially equal to the theoretical
`voltage of the battery to be charged and an amperage
`substantially equal to two times the maximum amperage
`of either the second or the third current limiting means.
`4. The battery charging apparatus of claim 1, wherein
`each current limiting means further comprises a light
`bulb having a predetermined maximum amperage sub-
`stantially equal to the maximum desired amperage for
`charging the connected battery.
`5. The battery charging apparatus of claim 1, wherein
`each current limiting means further comprises a visual
`indicator of the charge level of the connected battery.
`6. The battery charging apparatus of claim 1, wherein
`the current emitted by the power supply decreases as
`the battery connected thereto approaches a full charge
`condition and repels the current emitted by the power
`supply.
`7. The battery charging apparatus of claim 1, wherein
`the first and second batteries are connected to function
`as a single power source with the first battery charged
`by the first power source and isolated from the second
`power source as it charges the second battery.
`8. Apparatus for continuous simultaneous charging
`and thereafter maintaining the charge of a plurality of
`plate-type batteries, each having a known theoretical
`voltage, a positive terminal, and a negative terminal,
`comprising:
`a first power supply having an alternating current
`output;
`a first circuit loop connecting the first power supply
`to a first battery to be charged wherein the first
`circuit loop comprises:
`a first diode connected in the first loop between the
`first power supply and the positive post of the
`first battery to be charged;
`a second diode connected in the first loop between
`the fust power supply and the negative post of
`the first battery to be charged; and
`first current limiting means connected in the first
`loop to limit
`the maximum current flowing
`through the first loop to charge the first battery;
`a second power supply having an alternating current
`output;
`a second circuit loop connecting the second power
`supply to a second battery to be charged wherein
`the second 25 circuit loop comprises:
`a third diode connected in the second loop between
`the second power supply and the positive post of
`the second battery to be charged;
`a fourth diode connected in the second loop be-
`tween the second power supply and the negative
`post of the second battery to be charged; and
`second current limiting means connected in the
`second loop to limit the maximum current flow-
`ing through the loop to charge the second bat-
`tery; and
`a third circuit loop connecting the second power
`supply to a third battery to be charged wherein the
`third circuit loop comprises:
`a fifth diode connected in the third loop between
`the second power supply and the positive post of
`the third battery to be charged;
`
`5
`
`10
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`15
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`20
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`25
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`30
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`35
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`55
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`65
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`

`

`9
`
`5,371,454
`
`10
`11. The battery charging apparatus of claim 8,
`wherein each current limiting means further comprises
`a light bulb having a predetermined maximum amper—
`age substantially equal to the maximum desired amper-
`age for charging the battery.
`12. The battery charging apparatus of claim 8,
`wherein each current limiting means further comprises
`a visual indicator of the charge level of the connected
`battery.
`13. The battery charging apparatus of claim 8,
`wherein the current emitted by the power supply de-
`creases as the battery connected thereto approaches a
`full charge condition and repels the current emitted by
`the power supply.
`14. The battery charging apparatus of claim 8,
`wherein the first and second batteries are connected to
`function as a single power source with the first battery
`connected through the first
`loop to the first power
`source with the first loop being isolated from the second
`loop connecting the second battery to the second power
`source.
`1‘
`t
`*
`*
`*
`
`a sixth diode connected in the third loop between
`the second power supply and the negative post
`of the third battery to be charged; and
`third current limiting means connected in the third
`loop to limit
`the maximum current flowing
`through the loop to charge the third battery.
`9. The battery charging apparatus of claim 8, wherein
`the first power supply comprises a transformer capable
`of emitting a flow of electricity having a voltage sub-
`stantially equal to the theoretical voltage of the battery
`to be charged and an amperage substantially equal to
`the maximum amperage of the first current limiting
`means.
`
`10. The battery charging apparatus of claim 8,
`wherein the second power supply comprises a trans-
`former capable of emitting a flow of electricity having
`a voltage substantially equal to the theoretical voltage
`of the battery to be charged and an amperage substan-
`tially equal to two times the maximum amperage of the
`second or the third current limiting means.
`
`5
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`10
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`15
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`20
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`25
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`30
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`35
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`

`

`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE.
`CERTIFICATE OF CORRECTION
`
`_
`
`
`
`PATENT NU.
`DATED
`INVENTDHS)
`
`:
`1
`:
`
`5,371,454
`December 6, 1994
`Albert Marek
`
`‘
`
`
`
`
`
`It is certified that error appears in the above-identified patent and that said Letters Patent is hereby
`'
`corrected as shown below:
`
`Column 8, line 52 after "seeon " delete --25-—.
`
`
`
`Signed and'Sealed this
`
`Eleventh Day of April, 1995
`
`@0144 W
`
`Attest:
`
`
`
`
`
`
` Attesting Ofi‘icer
`
`Commissioner of Patents and Trademark:
`
`BRUCE LEI-{MAN
`
`
`
`12
`
`