The repairable battery pack device and method of use relates to battery packs, more particularly to repairable high energy density battery packs.
Lead acid batteries have been used extensively to address small electric apparatus needs. Unfortunately, lead acid batteries have numerous disadvantages. More particularly, most lead acid battery powered lawn mowers and small electric apparatuses typically suffer from poor performance due to the heavy weight, short run times and low range caused by the lead acid batteries. In addition, they require routine maintenance and several fluids to operate, which over time, can result in a leakage of harmful fluids into the environment as well as create explosive hydrogen gas when charging. These batteries have relatively short life cycles of only 300-400 charging cycles, can only practically use about 60% of their total capacity, and rapidly decrease in voltage and power as the batteries are discharged. The amount of energy required to charge lead acid batteries is much higher per energy density, so the charging efficiency is low. These batteries cannot be easily exchanged due to large size and weight, and a multitude of complicated battery cable connections. The large area required to install these batteries creates a design issue due to an adverse center of gravity situation both laterally and vertically, which leads to undesirable steering and handling issues especially on slopes. Further, such batteries cannot be easily repaired if there is a fault within any cells of the batteries, causing the need for complete replacement of a failed battery pack.
A high energy density battery such as Lithium-ion has been introduced to address many of these issues. Unfortunately, current lithium-ion battery pack designs include numerous disadvantages. More particularly, many lithium-ion battery packs are either relatively small in size such as a cordless battery powered hand-held drill or very large such as an electric car battery pack. Other current lithium-ion batteries require external Battery Management Systems when multiple batteries are connected to each other. Such lithium-ion batteries are difficult to install, replace, or repair. Many smaller lithium-ion batteries use a large amount of lateral physical space to store a relatively low capacity due to inefficient packaging and size. Many large electric car lithium-ion battery packs are often very heavy, physically large, and not configured for small electric apparatus or to be removable except during replacement due to failure. Furthermore, neither the plurality of complicated small lithium-ion packs nor single large packs can be easily installed into and out of most small electric apparatus with ease and efficiency.
Other issues related to current lithium-ion batteries relate to their inefficient internal construction. Current lithium-ion batteries suffer from an inability to be easy to repair if any faults arise from their plurality of internal cells that accumulatively make up their total voltage, thus making the battery very difficult, dangerous, and time consuming to repair and very costly to replace. Lithium battery packs are commonly constructed by welding all connections together from all cells and bundling everything together into a pack. This makes it very difficult to distinguish and replace any of the plurality of cells in the pack. Further, when current lithium-ion batteries have internal faults, they are very difficult to diagnose as a result of the lack of an easy and efficient means of measuring individual cell voltage.
The above considerations, and others, can addressed by the repairable battery pack device and method of use described below, which can be understood by referring to the specification, drawings, and claims. The repairable battery pack device and method of use generally relates an easy-to-repair high energy density battery pack suitable for use in small electric apparatuses, such as electric mowers, passenger/golf carts, material handling equipment, snow blowers, fertilizers, wood splitters, etc., although the repairable battery pack device and method of use described herein may in some embodiments, be utilized in other larger or smaller apparatuses suitable for use with an electric battery power source.
In at least some embodiments, the repairable battery pack device and method of use is directed to a battery pack device comprising: a plurality of bricks, each brick comprising: a plurality of battery cells, each having a positive polarity tab and a negative polarity tab, wherein the cells are secured together; a brick plate including a plurality of apertures for receiving the positive polarity tab and the negative polarity tab of each cell therethrough; a positive brick bus formed by the engagement of the positive polarity tab of each cell being engaged with the positive polarity tab of at least one adjacent cell; a negative brick bus formed by the engagement of the negative polarity tab of each cell being engaged with the negative polarity tab of at least one adjacent cell; a plurality of positive brick conductors secured to the positive brick bus; and a plurality of negative brick conductors secured to the negative brick bus; a battery box having a plurality of sides, wherein the bricks are positioned inside the battery box and adjacent to each other, and wherein the plurality of positive brick conductors and negative brick conductors of the plurality of bricks are connected in a series configuration such that a first brick of the plurality of bricks has first positive brick conductors not secured to the negative brick conductors of an adjacent brick, and a last brick of the one of the plurality of bricks has last negative brick conductors not secured to positive brick conductors of an adjacent brick; and a battery management module having an input interconnected with the last negative brick conductors, and configured to permit or prevent the passing of input power from the last negative brick conductors to a power output connector at an output of the battery management module, wherein the power output connector includes a positive output conductor interconnected with the first positive brick conductors, and a negative output conductor interconnected with the output of the battery management module.
Further, in at least some embodiments, the repairable battery pack device and method of use is directed to a battery pack device comprising: a plurality of bricks, each brick comprising: a plurality of battery cells, each having a positive polarity tab and a negative polarity tab; a positive brick bus formed by interconnection of the positive polarity tabs; a negative brick bus formed by interconnection of the negative polarity tabs; at least one positive brick conductor secured to the positive brick bus; and at least one negative brick conductor secured to the negative brick bus; a battery box having a plurality of sides, wherein the bricks are positioned inside the battery box, and wherein the positive brick conductor and negative brick conductor of the plurality of bricks are connected in a series configuration such that the positive brick conductor and negative brick conductor of each brick is interconnected, with the exception that a first brick of the plurality of bricks has a first positive brick conductor not secured to the negative brick conductor of another brick, and a last brick of the one of the plurality of bricks has a last negative brick conductor not secured to a positive brick conductor of another brick; and a battery management module having an input interconnected with at least one of the last negative brick conductor and the first positive brick conductor, and configured to permit or prevent the passing of input power from the at least one of the last negative brick conductor and the first positive brick conductor to a power output connector at an output of the battery management module.
In addition, in at least some embodiments, the repairable battery pack device and method of use is directed to a method of repairing a repairable battery pack comprising: providing a repairable battery pack having a battery box, a lid, a battery management module, and a plurality of bricks comprised of battery cells and wired together inside the box, each brick including a cell monitoring conductor, a positive conductor, and a negative, conductor, wherein one or more of the bricks is a faulty brick and the remaining bricks are non-faulty bricks; removing the battery box lid from the battery box; disconnecting, via one or more power connectors, a positive inside lid connector and a negative inside lid connector, wherein the positive inside lid connector and negative inside lid connector are interconnected with at least one of a battery management module and the bricks; disconnecting, via one or more first monitoring connectors, a positive capacity indicator conductor and a negative capacity indicator conductor from a capacity indicator secured to the lid; measuring the voltage of each of the bricks by connecting a cell monitoring device to a mating plug that is interconnected with the cell monitoring conductors; determining if the measured voltage of any one of the bricks is outside pre-determined parameters, and if outside the pre-determined parameters deem the brick to be at least one of the one or more faulty bricks; disconnecting, via one or more battery management module connectors, the battery management module; disconnecting, via one or more first positive brick connectors and first negative brick connectors, one or more first positive brick conductors and first negative brick conductors extending from the faulty brick; disconnecting, via a second monitoring connector, a second monitoring conductor extending from the faulty brick; removing the faulty brick from the battery box and install a replacement brick; connecting one or more second positive brick connectors and second negative brick connectors extending from the replacement brick to at least one of the battery management module connector and at least one of the non-faulty bricks; connecting, via a replacement monitoring connector, a replacement monitoring conductor extending from the replacement brick to the battery management module; and connecting the one or more power connectors and the one or more first monitoring connectors, and install the lid.
Additionally, the repairable battery pack device and method of use is directed for use in a small electric apparatus, wherein in case of a battery fault, the battery pack can be disassembled by removing the lid of the box, the brick voltage diagnosed by means of plugging in a digital reader, a faulty brick having a brick number can be located and replaced by disconnecting connectors between the faulty brick and other bricks in the battery pack, and connecting the cable connectors of a new brick.
Embodiments of the repairable battery pack device and method of use are disclosed with reference to the accompanying exemplary drawings, which are for illustrative purposes. Various portions of the device may be omitted from illustration in one or more FIGS. in order to provide a view of underlying components. The repairable battery pack device and method of use are not limited in application to the details of construction or the arrangement of the components illustrated in the drawings. The repairable battery pack device and method of use are capable of other embodiments or of being practiced or carried out in various other ways. In the drawings:
A battery pack 2 is provided by the invention as versatile and usable in numerous electrically powered apparatuses, such as an electric lawn mower, or other electrically powered devices and vehicles. Referring to
As noted above, the battery pack 2 includes a plurality of bricks 6 (
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The brick 6 can further include a plurality of rigid panels to at least partially encase the brick 6, such as a bottom panel 62, side panels 64, and a top panel 66 with cutouts for the conductors 50, 52 to pass through. To secure the rigid plastic panels, the panels 62, 64, 66 can be temporarily secured with tape. Shrink wrap 68 is then placed around the panels and heated to allow a tight encasement of the cells 30, forming the brick 6. To further protect and secure the brick 6, a sealant, such as an epoxy 70 can be poured over and around the top panel 66 to seal the conductors 50, 52 and the monitoring conductor 58 to prevent or limit water intrusion and stress damage. The brick 6 is now complete and can then be labeled for ease of identification later. To accommodate various installations, the size and shape of the bricks 6 can vary based on the size, shape, and quantity of cells 30 utilized. For example, in at least some embodiments, a four cell brick can be formed and used in combination with another four cell brick to produce a brick that equals the size of an eight cell brick. In other embodiments, other quantities of cells 30 can be utilized to form arrangements such as a two cell or one cell brick, which can be used alone or secured to another brick.
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One or more displays or indicators, such as the capacity indicator 18 can be connected to the bricks 6 and mounted to the lid 12 for checking the state of charge of the battery pack 2. In at least some embodiments, the capacity indicator 18 connected to a positive capacity indicator conductor 123 and a negative capacity indicator conductor 125. The positive capacity indicator conductor 123 is connected to the first positive brick conductors 82 of the first brick 80 and the negative capacity indicator conductor 125 is connected to the last negative brick conductor 98 of the last brick 96. The positive capacity indicator conductor 123 and a negative capacity indicator conductor 125 each include connectors 127. In at least some embodiments, the capacity indicator 18 includes a plurality of LEDS 13 or other indicators that are viewable through the lid 12 when the lid 12 is closed (
The battery pack 2 can be charged using various types of battery chargers, including Smart Chargers that can monitor data such as temperatures and faulty cell information and stop the charging process if necessary. Regardless of the use of a Smart Charger, the BMM 8 itself can be configured to provide similar monitoring features allowing the use of non-Smart Chargers. In at least some embodiments, the BMM 8 will monitor the total voltage output of the battery pack 2, the individual voltages of each brick 6, minimum and maximum voltages of each brick 6, and the voltage difference between highest and lowest voltages of the bricks 6. Furthermore, in at least some embodiments, the BMM 8 can: monitor the temperature of the bricks 6 using a temperature sensor 111 positioned between bricks 6 and a temperature sensor on the external surface of the BMM 8; detect improper connections or short circuits; and monitor charging currents in, and discharge currents out. As discussed above, the BMM 8 can be configured to prevent operations outside the safe operating range of the battery pack 2, for example by operating an internal protection device, such as a solid state relay, to shut off delivery of battery power to the external power connector 24 when necessary.
In at least some embodiments, the battery pack 2 is suitable for use in electric apparatuses, such as an electrically driven lawn mower and is configured to be installed in an area at least the same size or smaller than two typical industry standard size side-by-side golf cart batteries (the battery pack 2 measuring about 14.5 inches long by 10.25 inches wide by 12 inches tall). Further in at least some embodiments, the battery pack 2 is rated for about 48V 112 Ah, and up to four of the 48V 112 Ah batteries in this example can be connected in parallel to form up to a 48V 448 Ah battery pack 2. Each battery pack 2 can be used for single operations or in multiples. The battery pack 2 can be configured to include numerous variations of cell 30 and brick 6 quantities, voltages, and Amp-Hour capacities.
When multiple battery packs 2 are connected to an electric apparatus in a parallel configuration, if a fault occurs in one of the battery packs 2, a voltmeter can be used to determine which battery pack 2 is faulty. At this point, the faulty battery pack can be removed and the remaining battery packs 2 can remain connected to the electric apparatus and still function with the suspect battery pack missing, as their total voltage remains substantially the same. The faulty battery pack can be diagnosed and repaired without requiring replacement. The general procedure to repair the battery pack 2 begins by identifying where in the battery pack 2 the fault occurred. First, the battery pack lid 12 is removed, and then the first positive brick conductors 82 and the BMM output conductors 114 are disconnected from their respective positive and negative inside lid connectors 115, 117. Then the positive capacity indicator conductor 123 and the negative capacity indicator conductor 125 are disconnected from the lid 12. It is now possible to check the voltage of each brick 6 by connecting a cell monitoring device 121 to the mating plug 108. In at least some embodiments, the cell monitoring device 121 is a Cellmeter-7 Digital Battery Capacity Checker, as manufactured by Tomtop Inc. After connection of the cell monitoring device 121, a repair technician can scroll through the voltages for each brick 6 to check for erroneous voltages. If one or more bricks 6 have a voltage that is outside the required specifications, they can be deemed faulty and can be replaced by, first, unplugging the BMM input connectors 104 and removing the shelf 16 with the BMM 8 still installed. The brick 6 deemed faulty can now be identified by number and the positive brick connectors 54, negative brick conductors 52, and the monitoring wire connector plug 33 for that brick 6 can be pulled apart to separate the brick deemed faulty from the bricks 6 that remain. After an additional voltage check to be sure the brick 6 deemed faulty has been located, the technician can remove the brick 6 deemed to be faulty by sliding it out of the box 4. The brick 6 that is faulty can then be set aside for proper recycling. Another brick 6 can be provided as a replacement and charged to the same voltage as the battery pack 2 is inserted back into the box 4. The positive brick connectors 54, negative brick conductors 52, and the monitoring wire connector plug 33 for the brick 6 provided as a replacement, are interconnected. The shelf 16 can now be re-installed and the BMM output conductors 114, and the first positive brick conductors 82 can be reconnected respectively to the negative inside lid connector 115 and the positive inside lid connector 117. The capacity indicator 18 is reconnected, via the positive capacity indicator conductor 123 and the negative capacity indicator conductor 125, and the lid 12 is reinstalled. The battery pack 2 can be final-tested and returned to service.
Without this time-saving easy-to-repair battery pack, the entire battery with one faulty cell would likely have been deemed unrepairable due to high labor rates and safety concerns while repairing. This entire procedure requires no specialized tools, no welding or soldering, and is particularly safe, due to no bare wires being exposed (connectors are utilized). A much less experienced technician can perform this task compared to previous high-density (e.g., lithium) batteries that require excessive soldering and exposed wire ends which can be easily short circuited during the repair process. The total cost of this repair is about 1/13 the cost of a new battery pack and much faster and safer than other known types of repairs.
It is specifically intended that the repairable battery pack and method use not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. Further, the steps outlined above can be modified in various manners, such as performance in one or more alternate orders. The addition or exclusion of any step(s) discussed or not discussed, does not preclude a desired completion of the procedure. Accordingly, the foregoing description is meant to be exemplary only, the invention is to be taken as including all reasonable equivalents to the subject matter of the invention, and should not limit the scope of the invention set forth in the following claims. The use of the term plurality is intended to include one or more.