WO2016205386A1

WO2016205386A1 - Lithium-ion battery

Info

Publication number: WO2016205386A1
Application number: PCT/US2016/037654
Authority: WO
Inventors: Jeffrey M. ZELLER; Richard J. Gilpatrick; Michael Logan; Robert Koenen; Ryan Hahn; Sara Linginfelter
Original assignee: Briggs & Stratton Corporation
Priority date: 2015-06-16
Filing date: 2016-06-15
Publication date: 2016-12-22

Abstract

A battery system for use with outdoor power equipment includes a housing having a housing height, a housing depth, and a housing width, a positive terminal, a negative terminal, and a lithium-ion battery pack positioned within the housing, the lithium-ion battery pack electrically coupled to the positive terminal and the negative terminal, wherein the positive terminal and the negative terminal are spaced apart by a distance substantially the same as a standard distance between terminals of a standard lead-acid battery, wherein the housing height is substantially the same as a standard height of the standard lead-acid battery, wherein the housing depth is substantially the same as a standard depth of the standard lead-acid battery, wherein in the housing width is substantially the same as a standard width of the standard lead-acid battery, and wherein a volume of the lithium-ion battery pack is less than an interior volume of the housing.

Description

LITHIUM-ION BATTERY

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This application claims the benefit of U. S. Application No. 62/180,485, filed June 16, 2015, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] The present invention relates generally to the field of battery systems and, in some embodiments, to battery systems for outdoor power equipment. Outdoor power equipment includes lawn mowers, riding tractors, snow throwers, pressure washers, portable generators, tillers, log splitters, zero-turn radius mowers, walk-behind mowers, riding mowers, industrial vehicles such as forklifts, utility vehicles, etc. Outdoor power equipment may, for example, use an internal combustion engine to drive an implement, such as a rotary blade of a lawn mower, a pump of a pressure washer, the auger of a snowthrower, the alternator of a generator, and/or a drivetrain of the outdoor power equipment. Vehicles include cars, trucks, automobiles, motorcycles, scooters, boats, all-terrain vehicles (ATVs), personal water craft, snowmobiles, utility vehicles (UTVs), and the like. Outdoor power equipment, vehicles, engine driven equipment, engines and other engine related applications are collectively referred to as "equipment."

[0003] Equipment may include an electric starting system in which a starter motor powered by a battery starts the engine. Typically, such electric starting systems also include a user- actuated starter switch (e.g., a pushbutton or key switch) and a starter solenoid. The starter solenoid is the connection between a low current circuit including the starter switch and a high current circuit including the starter motor. To start the engine, the user actuates the starter switch, causing the starter solenoid to close so that the battery provides starting current to the starting motor to start the engine.

[0004] A conventional battery system typically includes a lead-acid battery. The rated voltage and discharge capacity of the lead-acid battery can vary. Typically, the rated voltage for a lead-acid battery used in outdoor power equipment is between 6 volts and 12 volts. Lead-acid batteries are filled with a liquid electrolyte, typically a mixture of water and sulfuric acid. The electrolyte is corrosive. Lead-acid batteries are temperature sensitive, which may result in the engine having difficulty starting or not starting at all in cold weather. Also, a lead-acid battery will degrade over periods of non-use and will gradually lose the ability to provide adequate voltage (i.e., lose charge or become completely discharged— lead acid batteries may lose approximately 1 percent of charge capacity per day of non-use). A lead-acid battery may need to be replaced seasonally, removed from the outdoor power equipment and stored inside, or otherwise maintained or serviced by a user.

Infrequent/intermittent use further exacerbates problems inherent to lead-acid batteries. Certain applications (such as outdoor power equipment) that are subjected to extreme temperatures and/or infrequent/intermittent use may cause premature failure of lead-acid batteries.

[0005] Lead-acid batteries of a particular rated voltage and discharge capacity have substantially standard dimensions for the spacing between the battery terminals, for the placement of the battery terminals (i.e., top or side mounted terminals), for the location of the positive battery terminal (i.e., left front position or right front position with the terminal side of the battery facing the user), for the size of the battery housing (i.e., height, width, and depth of the housing), and for the mounting points or other structures used to secure the battery to the equipment (e.g., flanges, tie-down points, unobstructed locations to accommodate hold downs, etc.). There are industry standard form factors for lead-acid batteries (e.g., Ul, U1R, 22F, 22NF, 26, 26R, etc.). This makes lead-acid batteries of a particular rated voltage and discharge capacity readily replaceable because a replacement battery will fit into the provided space and attach to an electrical system (e.g., via electrical leads connected to the battery terminals) and attach to the equipment (e.g., via hold downs securing the battery to a mounting location) in the same manner as the original battery (e.g., using the same electrical leads and hold downs). A "standard" battery is easily replaceable because batteries of the same size, form factor, terminal location, terminal orientation and terminal configuration can be readily purchased from a variety of sources and such standard batteries are able to be installed as a replacement battery in a piece of equipment without having to modify the mounting location of the original battery or make changes to or replace the wiring leads, hold downs or other components associated with the original battery in order for the replacement battery to make use of the mounting location, wiring leads, hold downs or other components associated with the original battery. For example, the following types of 12 volt batteries are among those considered to be standard for outdoor power equipment: 7U1L, 8U1L, 10U1L, 11U1L, 558MF, and 65 IMF. Each of these examples and other conventional lead-acid batteries have standard dimensions including a "standard distance between terminals" (center-to-center), a "standard height," a "standard width," a "standard depth," and a "standard cross-sectional area" or footprint (width times depth) that are well-known to those skilled in the arts of batteries and/or outdoor power equipment. For example, for 7U1L, 8U1L, 10U1L, and 11U1L lead-acid batteries, the standard height is 7 1/4 inches (184 mm), the standard width is 7 3/4 inches (197 mm), and the standard depth is 5 1/8 inches (130 mm). A distance or area is "substantially the same" as one of the standard distances or areas of a standard lead-acid battery when such a distance or area allows a battery or other component having such a distance or area to be readily used in place of the standard lead-acid battery. In some embodiments of the present invention, plus or minus 25% of the distance or area is the outer limit for a distance or area to be considered

"substantially the same" as one of the standard distances or areas. In some embodiments of the present invention, plus or minus 20% of the distance or area is the outer limit for a distance or area to be considered "substantially the same" as one of the standard distances or areas. In some embodiments of the present invention, plus or minus 15% of the distance or area is the outer limit for a distance or area to be considered "substantially the same" as one of the standard distances or areas. In some embodiments of the present invention, plus or minus 10% of the distance or area is the outer limit for a distance or area to be considered "substantially the same" as one of the standard distances or areas. In some embodiments of the present invention, plus or minus 5% of the distance or area is the outer limit for a distance or area to be considered "substantially the same" as one of the standard distances or areas. In some embodiments of the present invention, a distance or area the same as one of the standard distances or areas is considered to be "substantially the same" as one of the standard distances or areas.

SUMMARY

[0006] One embodiment of the invention relates to a battery system for use with outdoor power equipment, including a housing having a housing height, a housing depth, and a housing width. The housing includes a positive terminal, a negative terminal, and a lithium- ion battery pack electrically coupled to the positive terminal and the negative terminal, wherein the positive terminal and the negative terminal are spaced apart by a distance substantially the same as a standard distance between terminals of a standard lead-acid battery, wherein the housing height is substantially the same as a standard height of the standard lead-acid battery, wherein the housing depth is substantially the same as a standard depth of the standard lead-acid battery; and

wherein in the housing width is substantially the same as a standard width of the standard lead-acid battery.

[0007] Another embodiment of the invention relates to a battery system for use with outdoor power equipment, including a housing including a top, a bottom, a front, a back, a left side, and a right side. The housing includes a positive terminal positioned on the top, a negative terminal positioned on the top, wherein the negative terminal is positioned a first distance away from the positive terminal, and a lithium-ion battery pack electrically coupled to the positive terminal and the negative terminal, a first recess positioned on the bottom, and a second recess positioned on the bottom, wherein the second recess is positioned the first distance away from the first recess.

[0008] Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims.

BRIEF DESCRIPTION OF THE FIGURES

[0009] The invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, in which:

[0010] FIG. 1 is a perspective view of a standard lead-acid battery of the prior art.

[0011] FIG. 2 is a perspective view of a lithium-ion battery system, according to an exemplary embodiment.

[0012] FIG. 2A is a perspective section view of a lithium-ion battery cell, according to an exemplary embodiment. [0013] FIG. 2B is a perspective view of a lithium-ion battery pack, according to an exemplary embodiment.

[0014] FIG. 2C is a perspective view of a plurality of lithium-ion battery cells, according to an exemplary embodiment.

[0015] FIG. 3 is a front view of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

[0016] FIG. 3A is a section view of the lithium-ion battery system of FIG. 3 taken along line 3A-3A, according to an exemplary embodiment.

[0017] FIG. 3B is a perspective view of a portion of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

[0018] FIG. 3C is a front view of a portion of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

[0019] FIG. 4 is a back view of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

[0020] FIG. 5 is a back perspective view of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

[0021] FIG. 6 is a top view of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

[0022] FIG. 7 is a left side view of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

[0023] FIG. 8 is a bottom view of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

[0024] FIG. 9 is a front view of stacked lithium-ion battery systems of FIG. 2, according to an exemplary embodiment. [0025] FIG. 10 is a detailed view of the stacked lithium-ion battery systems of FIG. 9, according to an exemplary embodiment.

[0026] FIG. 1 1 is a top perspective view of the lithium-ion battery system of FIG. 2, according to an exemplary embodiment.

DETAILED DESCRIPTION

[0027] Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.

[0028] Referring to FIG. 1, a standard lead-acid battery 10 is illustrated. The battery 10 includes a housing 5, a positive terminal 10, and a negative terminal 15. The terminals 10 and 15 are spaced apart by a standard distance 20 between terminals as measured from the center of the terminal 10 to the center of the terminal 15. For each terminal, an electrical lead 17 and a fastener 19 (e.g., a bolt and nut) are used to electrically connect the terminal to the electrical system powered by the battery (e.g., a starting system of a piece of outdoor power equipment, such as a starter motor that starts an internal combustion engine that powers the equipment). The terminals 10 and 15 are mounted to the top of the housing 5 at a standard height 25. Industry standards exist for the type of terminals used with a standard lead-acid battery. For example, as illustrated in FIG. 1, terminals 10 and 15 are L terminals (LT). Other standard lead-acid battery terminals include SAE terminals, JIS terminals, embedded low profile terminals (ELPT), embedded high profile terminals (EHPT), embedded automotive post terminals (EAPT), automotive post and stud terminals (DT), universal terminals (UT), embedded universal terminals (EUT), automotive post terminals (AP), wingnut terminals (WNT), dual wingnut terminals (DWNT), stud terminals (ST), low profile terminals (LPT), embedded automotive post and stud terminals (DT), M terminals (M), and F terminals (F). The housing 5 has a standard width 30 and a standard depth 35, resulting in the standard footprint for the battery 100. The housing 5 has a standard width 30 and a standard depth 35, resulting a standard footprint for the battery 10. [0029] Standard lead-acid batteries, like battery 10, can be difficult or bothersome for users to replace. Users may discover that the battery for a certain piece of equipment has failed (i.e., has insufficient charge or has otherwise ceased to function as necessary) when attempting to start the outdoor power equipment to perform a task. The user must use tools to remove the failed battery from the equipment (e.g. to disconnect electrical leads connected to the battery terminals, to uninstall one or more battery hold downs, etc.), acquire a new battery, and use tools to install the new battery (e.g. to connect electrical leads to the battery terminals, to install one or more battery hold downs, etc.). The lead-acid battery may be heavy and may be mounted to the equipment in a location that is confined and difficult to access. It can be difficult for the user to access the lead-acid battery and awkward or difficult to move a lead-acid battery out of or into the mounting location on the equipment. Exposure to cold temperatures can reduce lead-acid battery life. Seasonal use (e.g., warm weather use or cold weather use) and sporadic use (e.g., once a week, several uses a month, etc.) can reduce lead-acid battery life. Accordingly, lead-acid battery life may be particularly limited for sporadically and/or seasonally used equipment (e.g., outdoor power equipment including lawn mowers, riding tractors, ZTRs, snow throwers, portable generators, standby generators, marine vehicles including boats and personal water craft, etc., small personal vehicles including motorcycles, snowmobiles, all-terrain vehicles, etc.), with a new battery needed every few years.

[0030] A battery 100 is illustrated in FIG. 2, according to an exemplary embodiment. Preferably, the battery 100 includes a lithium-ion battery. Lithium-ion batteries are rechargeable and typically have a longer life than a comparable lead-acid battery. Lithium- ion batteries are smaller in size and lighter in weight than comparable lead-acid batteries having the same or similar voltage ratings and charge/energy capacities. The battery 100 replaces a standard form factor lead-acid battery (e.g., the Ul form factor) and eliminates many of the shortcomings associated with lead-acid batteries. In some embodiments, the battery 100 with a Ul form factor weighs less than 6 pounds (2.7 kilograms). Rather than removing the failed lead-acid battery with tools, traveling to purchase a new lead-acid battery, and installing the new lead-acid battery with tools, the user can recharge the battery 100 in a charging station or with a charging connector or plug, and reattach the battery 100 to the equipment. In some embodiments, a lithium-ion battery can be recharged in five minutes or less to a level of charge sufficient to start a piece of outdoor power equipment. Or, if the user has a second rechargeable battery having a sufficient charge, there is no need to wait for the first rechargeable battery to recharge, the second rechargeable battery can be attached to the equipment and used while the first rechargeable battery is recharging. This reduces the amount of user time and effort necessary to change a failed battery and also simplifies the tasks of removing and installing the battery by eliminating the need to use tools. Also, the user saves money, because the battery 100 does not need to be periodically replaced with a new battery as frequently as a lead-acid battery does. The battery 100 can either be installed as original equipment by the manufacturer of the equipment or installed as an aftermarket replacement for a standard lead-acid battery.

[0031] The battery 100 includes a housing 105, a positive terminal 110, and a negative terminal 112. As shown in FIG. 2, the housing 105 includes a top 102, bottom 104, left side 106, ride side 108, front 120, and back 140. The terminals 110 and 112 are mounted on the top 102 of the housing 105. In some embodiments, caps can be included with the battery system 100 to protect/cover the terminals 110 when not in use. In some embodiments, the housing 105 further includes terminal mounting locations 210, 212 for respective positive and negative terminals. In this embodiment, an additional positive and negative terminal can be added to the battery 100. In other embodiments, the terminals 110, 112 can be moved to the alternative mounting locations 210, 212 so a single battery can be configured as a right hand (e.g., U1R) or a left hand (U1L) terminal arrangement. The terminals 110 and 112 are standard lead-acid battery terminals so that the same electrical leads used to electrically connect the positive terminal and the negative terminal of the original standard lead-acid battery to the piece of equipment are also used to electrically connect the positive terminal 110 and the negative terminal 112 of the battery 100 to a piece of equipment. The positive terminal 110 and the negative terminal 112 are spaced apart by a distance 115 substantially the same as the standard distance 20 between terminals of a standard lead-acid battery. The terminals 110 and 112 are positioned at a vertical height 145 substantially the same as the standard height of terminals 25 of a standard lead-acid battery. This allows the terminals 110 and 112 of the battery 100 to be connected to the leads (e.g., by a fastener) or other connection points that would typically be provided to electrically couple a lead-acid battery to an electrical system of the piece of equipment (e.g., to a starter motor, to a starting system or other electrical system, etc.). This eliminates any potential need for a user replacing the original standard lead-acid battery with the battery 100 to modify (e.g., splice, extend, etc.) or replace the electrical leads of the piece of equipment.

[0032] In some embodiments, the battery 100 includes two positive terminals 1 10 and two negative terminals 1 12. In this embodiment, the positive terminals 1 10 are located on the same side of the top 102 (e.g., near the right side 108) and the negative terminals 1 12 are located on the same side of the top 102 (e.g., near the left side 106). The housing 105 can be rotated to have the positive terminal positioned on the right-hand side of the top 102 (e.g., as in a U1R battery). When rotated approximately 180 degrees from this position, the housing 105 can have the positive terminal positioned on the left-hand side of the top 102 of the housing 105 (e.g., as in a U1L battery).

[0033] Referring to FIGS. 2-8, the housing 105 has a width 155 (e.g. a maximum width) and a depth 160 (e.g., a maximum depth) so that the housing 105 fits within the standard footprint of a standard lead-acid battery, that is the maximum cross-sectional area (i.e. width times depth) of the housing 105 is substantially the same as or less than the standard footprint, and the housing 105 has a height that in some embodiments is substantially the same as the standard height of a standard lead-acid battery and in other embodiments is less than the standard height of a standard lead-acid battery. This allows the battery 100 to be positioned in same location on the equipment as the standard lead-acid battery. There is no need to modify the equipment to use the battery 100 in place of a standard lead acid battery (e.g., retrofit or rearrange mounting surfaces, mounting points, or other mounting hardware, change wiring harness routings or locations, provide a larger footprint or volume, use different hold downs or mounting structures to secure the base to the mounting location of the equipment, etc.).

[0034] Referring to FIGS. 5-7, the left and right sides 106, 108 include one or more handle portions 150 to allow a user to grip the housing 105. The handle portions 150 extend from the right and left sides 106, 108 toward the inner volume of the housing 105. In some embodiments, the handle portions 150 can have a different shape and depth than the portions shown in FIGS. 5-7. The handle portions 150 do not extend outside of the standard battery form factor. The empty space within the housing 105 accommodates the handle portions 150. In one embodiment, the housing 105 further includes a back handle portion 152 proximate the top 102 and extending from the back 140 toward the inner volume of the housing 105 allowing a user to grip the housing 105 from the back 140. In some embodiments, the back handle portion 152 includes a protrusion 154 (e.g., lip, tab, etc.) for ease of gripping the back handle portion 152. The back handle portion 152 is located below the top 102 of the housing 105. The back handle portion 152 does not extend outside of the standard battery form factor. The empty space within the housing 105 accommodates the back handle portion 152.

[0035] Referring to FIGS. 3-4, the housing 105 is shown to include one or more inner channels 126 configured to allow drainage of fluid from the housing 105. In one

embodiment, the inner channel 126 is a cylindrical shape. In other embodiments, the inner channel 126 has a rectangular prism shape. In other embodiments, the inner channel 126 is any suitable shape to allow drainage from the housing 105. In one embodiment, the inner channel 126 is formed within the housing 105 proximate the sides 106, 108 and extending between terminals 110, 112 on the top 102 of the housing 105 to the recess 114 on the bottom

104 of the housing 105. In this configuration, any fluid that enters the housing 105 (e.g., through the terminals 110, 112) can flow through the inner channel 126 and exit the housing

105 through a drainage hole 180. As shown in FIG. 3 A, the bottom 104 of the housing 105 includes a drainage hole 180 to allow fluid from the inner channel 126 to drain through the bottom 104. In some embodiments, the drainage hole 180 is positioned within the recess 114 on the bottom 104. In other embodiments, the drainage hole 180 is positioned in the bottom 104 of the housing 105. The terminals 110, 112 extend through the top 102 and are therefore possible entry points for water to enter the housing 105. The inner channels 126 keep water that enters through the terminals 110, 112 away from the battery pack 170 and control circuitry 177. As shown in FIG. 3 A, the inner channels 126 are defined by one or more walls 127 to separate the inner channels 126 from the main or central portion of the interior volume 190 of the housing 105. The battery pack 170 and control circuitry 177 are positioned within the central portion of the interior volume 190 of the housing 105. Unwanted exposure of the battery pack 170 and control circuitry 177 to water is avoided by directing water that may enter at the terminals 110, 112 through the inner channels 126 and out of the housing 105 through the drainage holes 180. The inner channels 126 are accommodated by the empty space within the housing 105 due to the relatively small percentage of interior volume that the battery pack 170 takes up.

[0036] The battery 100 includes a lithium-ion battery pack 170 housed within the housing 105. In some embodiments, more than one battery pack 170 is housed within the housing 105. Referring to FIGS. 2B and 2C, the battery pack 170 includes one or more cylindrical cells 165 (shown in FIG. 2A) configured to have both positive and negative terminals. The positive terminal is indicated by a ringed end. The cylindrical cell contains a number of tabs that promote the transfer of energy between at least one anode and at least one cathode. The battery pack 170 has a configuration including a plurality of rechargeable cylindrical cells. These cells are lithium-ion cells and may be NMC, LFP, LCO, or other suitable chemistry. In one embodiment, the cells are "18-650" cells due to their 18 mm diameter and their 65 mm length. According to another embodiment, "20-650" cells are utilized. "20-650" cells are 20 mm in diameter and 65 mm in length. Each cell contains a positive and negative terminal wherein the positive terminal is typically distinguished by a crimped ring around the cell. The cells are configured in a series-parallel configuration, otherwise known as an "S-P" configuration. For example, multiple cylindrical cells may be coupled in parallel, coupled serially with the parallel combination of cells, or coupled only serially. In other

embodiments, the battery pack 170 includes one or more prismatic cells.

[0037] A geometric packaging effect can be seen specifically in the arrangement of cells in FIGS. 2B-2C. In the geometric packaging effect, cells are physically coupled in parallel rows of two cells being disposed end to end, coupled in geometric parallel with other cells. In some embodiments, the battery packs 170 include a top plate 172 and a bottom plate 174 capping the cells 165 on each end.

[0038] In some embodiments, the battery 100 may include circuitry 177 configured to protect the battery pack 170 from overcharging (e.g., an attempted jump start with a separate power supply). The circuitry 177 may include processing electronics including, but not limited to, a processing circuit and a memory. The individual battery cells and the combination or pack of battery cells included in a battery have an overcharge voltage threshold. Charging voltages above the individual cell overcharge threshold or pack overcharge threshold may damage the cell or cells. For example, a lithium-ion battery may use lithium cobalt oxide (L1C0O2) or other metal oxides (e.g., Μη2θ4, etc.) for the battery cathode. L1C0O2 battery cells have an overcharge threshold of approximately 4.2 volts per cell. For a three cell battery, the pack has a pack overcharge threshold of approximately 12.6 volts. As another example, a lithium-ion battery may use lithium iron phosphate (LiFePC^) for the battery cathode. LiFePC>4 battery cells have an overcharge threshold of approximately 4.0 volts. For a four cell battery, the pack has a pack overcharge threshold of approximately 16 volts. For example, a field-effect transistor (FET) or other appropriate transistor or semiconductor device may be used to prevent overcharging the battery 165 by stopping the flow of current to the battery cells. The FET may be triggered to stop the flow of current to the battery cells in response to the current exceeding an overcurrent threshold, to a voltage exceeding an overvoltage threshold, to a voltage below an under-voltage threshold, to a temperature exceeding an over-temperature threshold, and/or to a temperature below an under-temperature threshold. A second FET or other appropriate transistor or semiconductor device responsive to similar thresholds may be provided to stop the flow of current out of the battery cells.

[0039] The circuitry 177 implements a battery management system (BMS) for regulating the currents and/or voltages involved in the charging and discharging processes in order to ensure that the battery cells are not damaged or otherwise brought to problematic charge states. A BMS may be included within the battery and may block an electrical signal from being delivered to the cells of a battery, or may block a current being drawn from the cells of a battery based the current and voltage properties of the signal and/or of the battery.

[0040] The volume of the battery packs 170 is less than the interior volume 190 of the housing 105. In some embodiments, the battery packs 170 are less than one-quarter the size of the interior volume 190 within the housing 105 such that there is a relatively large empty space within the housing 105. In other embodiments, the battery packs 170 are less than one- third the size of the interior volume 190. In a typical lead-acid battery housing 5 (shown in FIG. 1), the interior volume is substantially filled by positive and negative battery plates and an electrolyte solution. In contrast, the majority of interior volume 190 within the housing 105 of the battery 100 is empty space. [0041] The battery pack 170 is positioned within the interior volume 190 of the housing 105. In one embodiment, the battery pack 170 is positioned in the bottom 104 of the housing 105. Accordingly, in some embodiments, the bottom 104 of the housing 105 is detachable from the top 102 and/or pivotally connected to the top 102 such that the battery pack 170 is accessible. In some embodiments as shown in FIGS. 3B-3C, the battery pack 170 is positioned within the top 102 of the housing 105. In some embodiments, the top 102 is detachable from the bottom 104 and/or pivotally connected to the bottom 104 such that the battery pack 170 is removable and accessible with the top 102.

[0042] In one embodiment as shown in FIG. 3B, the battery pack 170 is connected to the terminals 1 10, 1 12 at the underside of the top 102 with leads 117. The top plate 172 of the battery pack 170 includes a circuit board 176 with circuitry 177 and mounting locations 175. For each terminal 110, 1 12, an electrical lead 1 17 and a fastener 119 (e.g., a bolt and nut) are used to electrically connect the terminal to the battery pack 170 at mounting locations 175. In another embodiment as shown in FIG. 3C, the battery pack 170 is mounted to the underside of the top 102 within the housing 105. The top plate 172 of the battery pack 170 is attached to the underside of the top 102 with fasteners 1 19. In this configuration, if the top 102 is removed or pivotally opened from the bottom 104, the battery pack 170 will move with the top 102.

[0043] Referring to FIG. 8, the bottom 104 of the housing 102 is shown, according to an exemplary embodiment. The bottom 104 includes at least two recesses 1 14 each including a perimeter 1 16. The recess 1 14 is sized and shaped receive a terminal 1 10, 112. In one embodiment, each recess 1 14 extends to a depth from the bottom 104 that is greater than the height of the terminals 1 10, 1 12 above the top 102 of the housing 105. In some

embodiments, each recess 1 14 extends to a depth from the bottom 104 such that terminals with caps can be received therein. Each perimeter 1 16 is shaped to receive the terminals 110, 112.

[0044] Referring to FIGS. 9 and 10, the battery 100A can be stacked with another battery system 100B such that the terminals 110, 112 on the top 102 of one battery 100A engage with the recesses 114 on the bottom 104 of another battery 100A. Referring back to FIG. 8, the bottom 104 can include a second set of two recesses 1 14 located opposite and similarly mirroring the terminals 110, 112 if the battery system 100 was flipped from front 120 to back 140 or vice versa, such that either way the battery 100B is set on top of another battery 100A it fits into the recesses 114. The batteries 100A and 100B can be stacked for display and transport. Typical lead-acid battery packaging includes cardboard or other supports to space apart the top and bottom of stacked standard lead-acid batteries. The stackable nature of the batteries 100 A, 100B reduces the packaging size and simplifies packaging and display by eliminating the supports used with standard lead-acid batteries.

[0045] Referring to FIG. 11, in some embodiments, the housing 105 includes a port 144 to receive a charging cord 315. Once connected, the charging cord 315 can be plugged into an outlet to recharge the battery. In some embodiments, the port 144 can also be used with an appropriate connection cord to power a device other than a piece of equipment. For example, the port 144 may be a USB (shown separately as USB port 142), micro-USB, or other standard electrical connection port and can be used to connect an appropriate connection cord to the battery 100 so that the battery 100 may power a cell phone, tablet, or other device. In an exemplary embodiment, the port 144 and USB port 142 extend through a top flange 143 such that the ports are accessible from both the front 120 and the back 140 of the housing 105.

[0046] A user could replace an original standard lead-acid battery with the battery system according to the following exemplary method. Step 1 is disconnecting the electrical leads from the positive and negative terminals of the lead acid battery. Step 2 is removing one or more battery hold downs. Step 3 is removing the lead-acid battery from the battery mounting location. Step 4 is installing the base of the battery system at the battery mounting location. Step 5 is installing the one or more battery hold downs to secure the base to the battery mounting location. In some embodiments, the one or more battery hold downs are the same one or more battery hold downs previously used to secure the removed lead-acid battery. Step 6 is connecting the electrical leads to the positive and negative terminals of the base. In some embodiments, the electrical leads connected to the terminals of the base are the same electrical leads previously connected to the terminals of the removed lead-acid battery. Step 7 is inserting the removable rechargeable battery into the battery receptacle of the base. In alternative embodiments, the order or sequence or these steps may be varied or re-sequenced or one or more of these steps may be omitted. For example, step 7 could occur before step 4 or before step 6.

[0047] The substantially empty interior volume of the lithium-ion battery allows various features of the battery to exist. For example, the inner channels to drain water from the battery could not exist on a lead-acid battery because there would not be enough empty space to allow for channels within the housing. As another example, the recesses allowing stacking of the lithium-ion battery, and thus compact packaging, would not be possible with a standard lead-acid battery. The recesses are formed on the housing and extend into the interior volume of the housing, whereas such a configuration would not be attainable with a standard lead- acid battery.

[0048] The battery may be used as original equipment by an original equipment manufacturer ("OEM"). In this situation, the battery would not be a one-for-one replacement of a standard lead-acid battery originally included with the piece of equipment, but would instead be a direct substitute for a lead-acid battery such that a lead-acid battery would not be originally installed on the piece of equipment. Using the battery as original equipment may reduce warranty and other costs related to lead-acid batteries. Frequently, seasonal use outdoor power equipment may sit in a store or warehouse for an extended period of time. That time reduces the useful life of the lead-acid battery available to the user. For example, if a lead-acid battery has an expected life of two years and the lead-acid battery for the piece of equipment is unused for a year because of shipping time, time spent in a warehouse or store, etc., the user may be left with only one year of actual useful life of the lead-acid battery. If the battery system is installed as original equipment by an OEM, the potential user frustration of unexpectedly shorted battery life may be avoided because of the ease of recharging the removable rechargeable battery of the battery system.

[0049] The construction and arrangement of the apparatus, systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few

embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, some elements shown as integrally formed may be constructed from multiple parts or elements, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure. In alternative embodiments, the battery systems could be sized for automotive applications (such as passenger cars, trucks, etc.).

Claims

WHAT IS CLAIMED IS:

1. A battery for use with outdoor power equipment, comprising:

a housing having a housing height, a housing depth, and a housing width; a positive terminal;

a negative terminal; and

a lithium-ion battery pack positioned within the housing, the lithium-ion battery pack electrically coupled to the positive terminal and the negative terminal;

wherein the positive terminal and the negative terminal are spaced apart by a distance substantially the same as a standard distance between terminals of a standard lead- acid battery;

wherein the housing height is substantially the same as a standard height of the standard lead-acid battery;

wherein the housing depth is substantially the same as a standard depth of the standard lead-acid battery;

wherein in the housing width is substantially the same as a standard width of the standard lead-acid battery; and

wherein a volume of the lithium-ion battery pack is less than an interior volume of the housing.

2. The battery of claim 1, wherein the lithium-ion battery pack comprises a plurality of lithium-ion batteries.

3. The battery of claim 1, wherein the positive terminal and the negative terminal are positioned at a height substantially the same as a standard terminal height of the standard lead-acid battery.

4. The battery of claim 1, wherein the housing further comprises a top, a bottom, a front, a back, a left side, and a right side.

5. The battery of claim 4, wherein the top is detachable from the housing.

6. The battery of claim 4, wherein the lithium-ion battery pack is attached to the top of the housing.

7. The battery of claim 4, wherein the bottom is detachable from the top.

8. The battery of claim 4, wherein the lithium-ion battery pack is attached to the bottom of the housing.

9. The battery of claim 4, wherein the housing further comprises two recesses positioned on the bottom and configured to receive the positive terminal and the negative terminal of a second battery.

10. The battery of claim 4, wherein the housing further comprises four recesses positioned on the bottom and configured to receive the positive terminal and the negative terminal of a second battery in two different configurations.

11. The battery of claim 4, wherein the housing comprises an inner channel configured to contain a liquid that has entered the housing and drain the liquid from the housing.

12. The battery of claim 11, wherein the housing further comprises a drainage hole positioned on the bottom of the housing configured to drain the liquid from the housing.

13. The battery of claim 1, wherein the housing includes an electrical plug for supplying power to charge the lithium-ion battery pack.

14. The battery of claim 1, wherein the positive terminal and the negative terminal are positioned so that the same electrical leads used to electrically connect the positive terminal and the negative terminal of the standard lead-acid battery to a piece of equipment are also used to electrically connect the positive terminal and the negative terminal of the housing to the piece of equipment.

15. The battery of claim 1, wherein the volume of the lithium-ion battery pack is less than one-quarter the interior volume of the housing.

16. The battery of claim 1, wherein the volume of the lithium-ion battery pack is less than one-third the interior volume of the housing.

17. The battery of claim 1, wherein the housing is configured to replace the standard lead-acid battery having a Ul form factor.

18. The battery of claim 1, wherein the battery weighs less than six pounds.

19. A battery for use with outdoor power equipment, comprising:

a housing including a top, a bottom, a front, a back, a left side, and a right side comprising:

a positive terminal positioned on the top;

a negative terminal positioned on the top, wherein the negative terminal is positioned a first distance away from the positive terminal; and

a lithium-ion battery pack electrically coupled to the positive terminal and the negative terminal;

a first recess positioned on the bottom; and

a second recess positioned on the bottom, wherein the second recess is positioned the first distance away from the first recess.

20. The battery of claim 19, wherein the first recess and the second recess are configured to receive the positive terminal and the negative terminal when the housing is positioned on top of a second housing of a second battery.