Battery management system with adiabatic switched-capacitor circuit

Abstract

An apparatus for switching between powering a load from a battery and powering the load from another power source includes a battery manager and a switched-capacitor network, wherein the switched-capacitor network comprises a plurality of capacitors, first and second switch sets, and a controller, wherein the controller causes the switched-capacitor network to transition between a first state and a second state.

Having described the invention, and a preferred embodiment thereof, what is claimed as new, and secured by Letters Patent is: 
     
         1 - 68 . (canceled) 
     
     
         69 . An apparatus comprising a battery manager, a switching network, a battery charger for charging a battery, and a first controller, wherein said battery manager comprises an input terminal for coupling to an AC/DC converter, wherein said switching network comprises first and second switch sets, wherein said switching network, when connected to a capacitor set that comprises a capacitor, forms a switched-capacitor network, wherein closing switches in said first switch set and opening switches in said second switch set arranges said capacitor set into a first state, wherein closing said switches in said second set and opening said switches in said first set arranges said capacitor set into a second state, and wherein, in operation, said controller causes said switched-capacitor network to transition between said first state and the second state at a specific frequency, thereby transferring charge between said capacitor set and terminals of said switched-capacitor network. 
     
     
         70 . The apparatus of  claim 69 , wherein said battery manager comprises said switched-capacitor network. 
     
     
         71 . The apparatus of  claim 69 , wherein said battery manager comprises an input and a step-down converter, wherein said input is connected to said AC/DC converter, and wherein said switched-capacitor network is between said step-down converter and said input. 
     
     
         72 . The apparatus of  claim 69 , wherein said battery manager comprises a step-down converter connected to said input terminal and to said switched-capacitor network and a switch that selectively connects and disconnects a battery from said switched-capacitor network and from an output terminal of said battery manager. 
     
     
         73 . The apparatus of  claim 69 , wherein said battery manager comprises a step-down converter connected between said input terminal and said switched-capacitor network and a switch that selectively connects and disconnects said battery from said switched-capacitor network and an output of said battery manager. 
     
     
         74 . The apparatus of  claim 69 , wherein said switched capacitor-network connects to an input terminal of said battery manager and wherein said battery manager further comprises a step-down converter that connects to said switched-capacitor network and to an output terminal of said battery manager and a switch that selectively connects said battery to said switched-capacitor network and to said output terminal. 
     
     
         75 . The apparatus of  claim 69 , wherein said battery manager comprises a step-down converter, wherein said step-down converter comprises an inductance, and wherein said switched-capacitor network relies on said inductance of said step-down converter to limit a rate of change of charge present on said capacitor. 
     
     
         76 . The apparatus of  claim 69 , wherein said AC/DC converter comprises said first controller, a charge pump, and a switching regulator connected to said charge pump, wherein said first controller controls said switching regulator and said charge pump. 
     
     
         77 . The apparatus of  claim 69 , wherein said switched-capacitor network comprises a charge pump and an inductance coupled to said charge pump. 
     
     
         78 . The apparatus of  claim 69 , further comprising rate-control circuitry, wherein during operation of said switched-capacitor network, said capacitor has an amount of charge stored thereon, and wherein said rate-control circuitry is configured to constrain a rate at which said amount of charge is changed at least in part as a result of causing charge to pass through an inductance. 
     
     
         79 . The apparatus of  claim 69 , wherein said battery is configured to receive energy wirelessly from an AC source. 
     
     
         80 . The apparatus of  claim 69 , wherein said battery charger switches between attempting to maintain a constant current while charge is being provided to said battery and attempting to maintain a constant voltage while charge is being provided to said battery. 
     
     
         81 . The apparatus of  claim 69 , further comprising a travel charger, wherein said battery manager is a constituent of said travel charger. 
     
     
         82 . The apparatus of  claim 69 , wherein said battery-charger is a CCCV charger. 
     
     
         83 . The apparatus of  claim 69 , wherein said controller comprises an isolation barrier between a primary and secondary section thereof. 
     
     
         84 . The apparatus of  claim 69 , wherein said switched-capacitor network is one that, during operation thereof, causes said capacitor to experience a change in charged stored therein by causing charge to be passed through a non-capacitive element. 
     
     
         85 . The apparatus of  claim 69 , further comprising a travel adapter, wherein said AC/DC converter is a constituent of said travel adapter, wherein said travel adapter comprises a USB port, and wherein said travel adapter receives an AC voltage and outputs a DC voltage at said USB port. 
     
     
         86 . The apparatus of  claim 69 , wherein said battery manager comprises said battery charger and a step-down converter, wherein said step-down converter is disposed such that, in operation, energy for charging said battery and energy for powering said load both pass through said step-down converter. 
     
     
         87 . The apparatus of  claim 69 , wherein said battery manager comprises said battery charger and a step-down converter, wherein said step-down converter is disposed such that, in operation, energy for charging said battery passes through said step-down converter and energy for powering said load bypasses said step-down converter. 
     
     
         88 . The apparatus of  claim 69 , further comprising a bypass switch control circuit to control slew rate of voltage transitions in said switched-capacitor circuit.