Patent Publication Number: US-11398742-B2

Title: Charge state control system and device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of a continuation of U.S. Nonprovisional patent application Ser. No. 16/926,720, titled, “CHARGE STATE CONTROL SYSTEM AND DEVICE,” filed Jul. 12, 2020, which is a continuation of U.S. Nonprovisional patent application Ser. No. 16/558,479, titled, “CHARGE STATE CONTROL SYSTEM AND DEVICE,” filed Sep. 3, 2019, now U.S. Pat. No. 10,714,957, the disclosure of each of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     In general, this invention relates to a charge state control system and device. In particular, the present invention sets forth a separate hardware device for controlling the current flowing to a consumer device in order to limit the charge of the battery in the consumer device to a specified charging range. 
     BACKGROUND 
     It is well established through current research that lithium-based batteries suffer a great reduction in achievable cycle life (overall useable lifespan) when repeatedly charged to and held at a voltage corresponding to full capacity (100%, approx. 4.2-4.25 V). The stated loss in capacity and cycle life is due to the fact that lithium cells are stressed and suffer from internal degradation when held at charge levels higher than 80%, especially in combination with elevated temperatures during charging (&gt;35 C). However, it is not in the interest of device manufacturers to reduce the maximum charge voltage or alter the charging regime of integral lithium batteries in consumer electronics for various reasons. 
     Manufacturers have the desire to advertise the highest possible number of hours attainable between charges. They accomplish this by charging the internal lithium cells to the highest voltage possible without compromising safety. This leads to a longer time period between charges when the device is new, but comes at the expense of overall useable battery life in the long run, often causing noticeable loss of capacity in as little as 6 months. Once capacity is lost, the battery will not last anywhere near the initial time period before requiring a charge. Secondly, consumer electronic devices are considered disposable, despite their high prices, and manufacturers build in this obsolescence to sell more devices or monetize integral battery replacements on existing devices. Consumers have little to no control over this as battery charging regimes are hard coded and not user configurable. Taking control of the battery charging process would allow consumers to extend the useable lifespan of their device by improving overall battery performance over a much longer period of time. 
     Currently, there is no automated solution for these issues. In order to take control of the maximum battery charge percentage, a user must manually monitor the battery charge percentage and unplug the device from the charging apparatus before the user&#39;s desired charge level is obtained and/or exceeded. It is up to the user to manually control this process. Should a user not closely monitor the battery charge of the device, maximum battery charge level will be reached and degradation of the battery will occur. On devices with Android operating systems, the device can be “rooted” (also known as removing manufacturer security and protection of the device software) so that power users can take control of the battery charging hardware via modifications to operating system code. This is not recommended nor desirable as it invalidates device warranty, makes the device less secure by eliminating regular security updates, and also limits the use of mobile payment applications. 
     While various charging circuits exist, none of them contemplate a solution to this problem. 
     U.S. Publication No. 20150180248 teaches an apparatus and method for protecting a battery from over voltage by using two battery protection circuits (analog and digital) that monitor the battery charging voltage and produce a signal when the voltage is outside of certain reference voltage ranges. The two protection circuits control a relay that is electrically connected to the battery protection circuit in order to control the battery charging voltage. A microcontroller unit has internal software to compare the measured voltages to the reference voltages. The relay is opened when the control signal mixer receives a positive signal from the first or second battery protection circuits. 
     U.S. Pat. No. 10,116,149 teaches an automatic control system for a rechargeable battery system. The system measures the state of charge of the battery and automatically switches from charging to discharging depending upon threshold limits that have been either pre-set or dictated by a user. A microprocessor is coupled with the battery system and the automatic controller. The microprocessor includes a program that controls the charging based on various configuration data. 
     European Patent application No. EP3266642 teaches an apparatus for preventing overcharge of a battery in an eco-vehicle, particularly in the case in which the battery management system fails. The system relies on a reference voltage or threshold voltage and automatically redirects current when the reference voltage is reached. A relay is used to allow or block charging of the battery. 
     Chinese Patent Application No. 106684482 teaches a battery overcharge protection system for charging rechargeable batteries that are in a charger. The application uses hardware and software protection of the batteries by using an insulation detection module that has internal software as the first line of control and comparators for the second line of hardware control. A switch or relay is turned off when the voltage of the battery is greater than a reference voltage. 
     Chinese Patent Application No. 106788076 relates to battery overcharge protection systems for vehicles, in this case a balance car. The overcharge protection system protects the battery from becoming overcharged due to charge being fed to the battery during braking. A relay is used to disconnect the charging circuit once a maximum charging voltage is reached. 
     Many different charging standards and voltages exist in personal electronic devices today. Typical USB-based charging regimes of 2.1 A and 5V DC are not as common anymore, and manufacturers are opting in favour of variable voltages and higher amperage limits for faster charging capability. Many different charging standards exist today (such as USB PD 2.0, Qualcomm Quick Charge 1.0/2.0/3.0, Apple Fast Charge, Motorola TurboPower, MediaTek Fast Charge, Huawei Fast Charge, etc). Voltages can range from 3.3 V DC up to 20 V DC, and currents can range from 0.5 A to 5 A. Also, communication between the power supply and the device being charged cannot be interrupted, as the voltage and current negotiation between them occurs over a USB serial connection. This variability and complexity creates difficulty when attempting to design a universal charge controller compatible with all devices. 
     SUMMARY 
     The present invention provides a charge state control system that is a fully automated solution, works automatically each time the device is plugged in, and automatically extends the life of the internal lithium battery according to the charge settings inputted by the user during initial setup. No manual interaction is required, and no device modification is required. The present invention is able to operate with the many different charging methods and cable types available for charging consumer devices on the market today. 
     In one example embodiment, the present invention relates to a physical charge state control hardware device in the form of an electronic printed circuit board consisting of power supply components, a microprocessor, a communication device, a relay, male and female USB ports (type A or type C as required), transistors, diodes, and an LED indicator. The power supply components can include voltage regulators, buck/boost transformers and/or capacitors. The communication device can be used for Bluetooth or WiFi controlled circuits, however it is optional for USB controlled circuits. 
     The hardware device can be physically enclosed on its own, or within other equipment such as a device charger, charging cable, or wireless charging pad/stand. The circuit can also be modified depending on the power input, for example using AC voltage when the circuit is integrated into the device charger vs DC voltage when the circuit is standalone, integrated into a device charging cable, or integrated into a wireless charging stand. 
     The present invention has much value for the end user of consumer electronic devices by extending the useful life of a user&#39;s internal lithium battery. This saves the user money by allowing them to keep their devices for a much longer period of time, and/or eliminating costly and invasive battery replacements of the internal lithium battery. 
     In one aspect of the present invention a software application on a consumer device monitors the charge percentage of the internal battery. The software application uses a communication protocol to connect to the charge state control hardware device and communicate with the microprocessor on the hardware device. The software application instructs the microprocessor to allow or disallow charging current to flow to the consumer device depending upon the battery charge percentage. A relay on the circuit board opens or closes depending upon instructions from the microprocessor. When the consumer device is removed from the control charger device and disconnects from the charge state control circuit board, the charger can operate normally for use with other devices. 
     Contrary to prior known solutions, the present invention does not monitor battery voltage directly nor is the primary purpose to prevent overcharging of a consumer device battery. The software or app component that resides on the consumer device allows the user to configure a maximum battery charge percentage of less than full. In this manner, the present invention allows the user to prevent the device battery from fully charging, for example, the desired battery charge percentage can be set to 80% instead of 100%. Overcharging is not a consideration at the lower charge levels. 
     The present invention prevents a consumer device and the consumer device factory charger from ever allowing the consumer device battery to reach a full charge of 100%. The user is allowed to set a desired charge level to be maintained, at a value less than full capacity. It works in conjunction with the factory charger, or alternatively, can be incorporated into a wall charger and/or wireless charger. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be further understood from the following description with reference to the attached drawings. 
         FIG. 1  illustrates a circuit schematic for the charge state control hardware device. 
         FIG. 2  illustrates the circuit schematic of  FIG. 1  with black boxes around the various components. 
         FIG. 3  illustrates a flowchart of the software application functionality on the consumer device. 
         FIG. 4  illustrates a flowchart of the microprocessor functionality on the hardware device. 
         FIG. 5  illustrates a sample schematic of the circuit for the hardware device. 
         FIG. 6  illustrates a circuit schematic of another embodiment for the charge state control hardware device. 
     
    
    
     DETAILED DESCRIPTION 
     A preferred embodiment of the present invention will be set forth in detail with reference to the drawings, in which like reference numerals refer to like elements or method steps throughout. 
     In one embodiment, the present invention solves the issue of preserving the cycle life and charge capacity of lithium batteries in consumer devices by utilizing the processing capability of the electronic device itself. A software application is installed on the consumer&#39;s device to monitor charge level and battery temperature. A microprocessor-controlled relay circuit is provided in the charge state control hardware device for interrupting charging current. The hardware device can be situated within the charging circuit of the consumer device, whether provided by a wired or wireless charging means. Alternatively, the hardware device can be provided as a separate component. The software application utilizes readily available communication protocols such as Bluetooth, Wi-Fi, and/or USB serial connection to communicate with the microprocessor within the hardware device to command the relay within the hardware device to turn charging current on and off as required. 
     Should the device need to be charged in more than one location, the software application is able to pair with and control many hardware devices without any repeated requirement for re-configuration or re-pairing. 
     The present invention is compatible to be used with various consumer devices such as smartphones, tablets, laptops, and tablet computers (running Android, iOS, Chrome OS, or Windows 10). 
     In one example embodiment, the present invention uses a piggy-back design that works in conjunction with the device power supply. The charge state control hardware device plugs into the USB port on the consumer device power supply, and the manufacturer&#39;s charging cable for the consumer device then plugs into the charge state control device. The piggy-back design represents an easy way for consumers to control charging without making a large investment. 
     In another example embodiment, the hardware device can be incorporated into a consumer device power supply to create a single unit that both develops the DC charging voltage and interrupts it all in one. This is a variation that would appeal to some consumers who do not wish to carry an additional piece of hardware with them for controlling the battery charge level. 
     In a further example embodiment, for wireless charging pads/devices, the hardware relay circuitry for the hardware device could be incorporated into the charging pad itself, once again representing an all-in-one solution where preferred. 
     The present invention is able to operate with the many different charging methods and cable types available for charging consumer devices on the market today (for example, Apple Lightning, USB-A, USB-C, Qi-Wireless Charging, etc.). The present invention has been designed and tested to successfully deal with constantly varying voltages and currents without impeding the charge negotiations between the consumer device and manufacturer&#39;s power supply. It works with all fast charge standards and brands, including wireless chargers. 
     A user is enabled to configure the maximum charge level depending on personal usage patterns and desired device lifespan improvement by using the software application as an interface. The user can also configure more complex charging profiles that involve time-based limits. For example, if a user plugs in their device for charging at 10 PM, charging capacity can be limited to 60% until 6 AM, and then the limit can change to 80% from 6 AM to 10 PM. There are many possibilities for different variations of configuration depending on user preferences. 
     Battery charge percentage ranges can be set by the user, however the best use of the invention would be to limit the maximum charge percentage to between 40% and 80%, dependent upon user needs. At a maximum charge of 60%, this will allow the user to achieve approximately 8 times more cycle life from their lithium battery when compared to charging fully to 100% every time. If 60% maximum charge limit is too inconvenient for the user, an 80% maximum charge percentage can be used to achieve approximately 4 times the cycle life when compared to charging up to 100% every time. The preferred range to realize optimum benefit from the automated charge state control system would be between 60% maximum battery charge (for overnight use), and 80% maximum battery charge (for all other charging events except overnight charging). In one example embodiment, the charge state control system includes default settings for the maximum battery charge. 
       FIG. 1  shows a circuit schematic for the charge state control hardware device  10 . 
       FIG. 2  shows the circuit schematic of  FIG. 1  with black boxes around the various components. The microprocessor  20  is a simple form of programmable logic controller that receives commands from the application software installed on the consumer device and energizes an output accordingly to open or close the relay contacts within the transistor relay circuit  22 . The microprocessor  20  is provided as part of the charge state control hardware device  10  and can communicate with the software application on the consumer device via wireless or wired communication (Bluetooth, Wi-Fi, or direct USB serial connection through the charging cable). Communication is enabled via the integrated communication device within the microprocessor, however the microprocessor  20  can also be separated from the communication device and interact with it through a serial connection on the printed circuit board. The communication device (integrated or not) enables the hardware device  10  to be transportable to any location as long as the application software is in connection proximity. 
     In one example embodiment, the microprocessor  20  features a programmable timer in order to receive timing commands from the software application. The timer function can be automatically activated anytime the communication connection with the software application is lost, for example in the event that the consumer device is powered off, the consumer device goes to sleep or if wireless communication is lost. The timer function from the software application provides the microprocessor  20  with the approximate estimated time left until the device battery is expected to reach the user&#39;s desired charging set point. The microprocessor can continue to allow charging current to flow from the device charger to the device for the estimated amount of time when the timer function is active. When the timer finishes, the microprocessor  20  interrupts the charging of the device by opening the relay. The timer function can be cancelled part way through if communication is reestablished with the software application. 
     In another example embodiment, the present invention employs a voltage regulation circuit  24  for enabling the universality of the hardware device with respect to the different consumer devices on the market. Each consumer device comes with a proprietary charger that outputs a certain voltage. Furthermore, many fast charging algorithms utilize variable voltages for charging output, meaning that the factory device charger and the device negotiate charging voltages according to pre-established parameters. In addition, the microprocessor  20  can only operate on a single preset voltage. In order to accommodate the wide possibility of input voltages and to supply the microprocessor with the exact voltage required, the voltage regulation circuit  24  boosts or trims any voltages that are too high or too low for the microprocessor and other control circuitry. This allows the hardware device to be applicable to virtually any consumer device. Depending on the type of consumer device and the different possible embodiments of the hardware device, this circuitry can be made to operate with various input and/or output voltages, examples of which include 3.3V to 20V DC, or 120V to 240V AC. 
     A transistor relay circuit  22  is provided which can include transistors, diodes, and relay contacts. This circuit allows the microprocessor output signal to allow or disallow the charging current to flow from the factory consumer device charger through to the consumer device, whether the hardware device  10  is incorporated within the consumer charger or provided as a piggy-back design as a separate device which connects to the consumer charger. 
     In a further embodiment, there is provided a connection to the consumer device charger  26  and a connection to the consumer device  28 . These terminals allow the factory consumer device charger and the consumer device, respectively, to connect to the hardware device. In this example the hardware device is depicted as a “piggyback” unit, in which both the factory consumer device charger and the consumer device connect to the hardware device. However, the entire circuit can be physically combined with and/or built into a device charger or wireless device charger. 
       FIG. 3  shows a flowchart of the software application functionality on the consumer device. The software application waits until the hardware device is plugged in or available for connection. Once available, the current battery percentage of the consumer device is determined and compared to the desired charge level. The setting for the desired charge level can be based on many different parameters, such as time of day, user&#39;s desire charge range, user&#39;s desired maximum battery temperature and/or user&#39;s wake up alarm. If it is determined that the charge state control hardware device should be enabled, the consumer device communicates through the connection to the consumer device  28  to the microprocessor  20  to close the relay contacts in the transistor relay circuit  22 . If it is determined that the charge state control hardware device should not be enabled, the consumer device communicates through the connection to the consumer device  28  to the microprocessor  20  to open the relay contacts in the transistor relay circuit  22 . The optional timer function can be updated to estimate the time remaining to reach the user&#39;s desired battery percentage level and send the time remaining to the timer circuit in the microprocessor on the hardware device. 
       FIG. 4  shows a flowchart of the microprocessor functionality on the hardware device. Once the software application is available for connection, the microprocessor receives an instruction to open or close the relay. The microprocessor either energizes or de-energizes the output to open or close the relay depending upon the instruction. If the instruction is to close the relay, the microprocessor receives the estimated time remaining to reach a user&#39;s desired battery percentage level from the software application on the consumer device. If the consumer device is still connected to the hardware device, the timer is not started and normal operation continues. If the consumer device is no longer connected to the hardware device, the timer function is activated and the relay is opened once the timer expires. If a connection to the software application is reestablished prior to the expiry of the timer, normal operation is resumed. 
       FIG. 5  shows a sample schematic of the circuit for the hardware device. 
       FIG. 6  shows a further embodiment of the circuit for the hardware device. This second design eliminates the use of USB input and output ports that were used in the embodiment of  FIG. 2 . Instead, this embodiment plugs directly into the electrical wall outlet, and the prongs of a mobile or laptop charger plug directly into the hardware device. In this embodiment, the hardware device is placed ahead of the consumer device charger instead of between the consumer device charger and charging cable. In this arrangement, the electrical wall outlet is followed by the hardware device, followed by the consumer device charger, and lastly followed by the consumer device charging cable leading to the consumer device. This embodiment works for smart phones as well as laptops since the laptop electrical plug can now directly be connected to the hardware device in a similar fashion to a phone charging brick. In fact, any consumer device or charger having a standard electrical plug can be attached to the output receptacle of the hardware device. 
     In terms of more detailed differences, comparing  FIG. 2  and  FIG. 6 , there are the following elements in  FIG. 2 :
     a. Item  26 —connection to the consumer device charger (Input connector intended to plug into the phone charging brick)   b. Item  28 —connection to the consumer device (Output connector intended to plug into the phone charging cable)   c. Item  24 —Voltage regulation circuit   d. Item  20 —microprocessor with Bluetooth/Wifi radio   e. Item  22 —Transistor Relay Circuit (controlling a standard contactor relay)   

     In the embodiment of  FIG. 6 , the connection  26  and connection  28  of  FIG. 2  are changed from USB type connectors to proper 120 V electrical plugs/receptacles. The input connection  61  of  FIG. 6  is a 3-prong electrical plug directly connectable to a building wall outlet, and the output connection  62  is a 3-slot electrical receptacle. 
     In the example embodiment of  FIG. 6 , besides the above changes,  FIG. 6  also includes the remaining components of  FIG. 2 , although their functionality is altered in order to accommodate the 120-240V AC electrical current that is commonly supplied via building electrical outlets around the world, rather than the 5-20 V DC current that a USB charger port typically supplies, as used in  FIG. 2 . 
     In one example embodiment, in order to accommodate the higher voltage and the AC current (rather than DC), the voltage regulation circuit  24  is slightly revised when compared to  FIG. 2 . While the core purpose is still to provide power to the integrated microprocessor  20  and Bluetooth/WIFI radio as well as the transistor relay circuit  22 , instead of a boost controller as per  FIG. 2 , there is provided a multi-tap transformer  63  to bring the voltage down from 120-240 V to 5 V and a rectification bridge to change the current type from AC to DC. 
     As discussed for  FIG. 2 , the microprocessor  20  and Bluetooth/WIFI radios can be fully integrated into one single unit, or split up into multiple connected units. 
     As discussed for  FIG. 2 , the transistor relay circuit  22  controls a discrete contactor or solid state style relay. In one example embodiment, the relay changes slightly to accommodate 120-240 V AC current on the switched side, whereas the control side remains at 5 V DC as was previously in  FIG. 2 . 
       FIG. 6  is only one example embodiment of a possible setup and arrangement of the placement of the hardware device between the wall outlet and the consumer charger. Other example embodiments are possible, based on other arrangements of the hardware device relative to the consumer charger. 
     The specific examples provided herein relate to a charge state control unit, however, the materials, methods of application and arrangements of the invention can be varied. For example, the microprocessor could calculate the timer function rather than receiving the estimated timer function from the software application. As a further example, the location of the hardware device can be altered to be located in any order relative to the consumer charger, the consumer device, the consumer charging cable and the wall outlet. 
     The scope of the claims should not be limited by the preferred embodiments set forth in the examples but should be given the broadest interpretation consistent with the description as a whole.