# US 12,191,698 B2 · Power management for removable batteries > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,698 B2 - Document ID: US12191698B2 - Status: Granted - Kind: B2 - Application number: 17/768,775 - Filed: 2021-04-13 - Published: 2023-05-11 - Granted: 2025-01-07 - Earliest claimed: 2021-04-13 - Assignees: Google Inc. - Applicants: Google LLC - Inventors: Chia Hang Yeh; Hsing-Sheng Lin - Web page: https://patentgrep.com/patent/US12191698B2 ## CPC - H02J 7/96: in response to battery voltage - G02C 5/143: {having special ear pieces} - G02C 11/10: {Electronic devices other than hearing aids} - G06F 1/263: {Arrangements for using multiple switchable power supplies, e.g. battery and AC (G06F1/30 takes precedence)} - H02J 1/10: Parallel operation of DC sources - H02J 7/342: {The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging (with circuits for polarity protection H02J7/68)} - H02J 7/50: acting upon multiple batteries simultaneously or sequentially - H02J 7/52: for charge balancing, e.g. equalisation of charge between batteries - H02J 7/575: {Parallel/serial switching of connection of batteries to charge or load circuit} - H02J 7/62: against overcurrent - H02J 7/663: {using battery or load disconnect circuits (H02J9/002 takes precedence)} - H02J 7/84: Control of state of health [SOH] - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - G02C: SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES (trial frames for testing the eyes A61B3/04; goggles or eyeshields not having the same features as spectacles A61F9/00) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An electronic device may include a power management subsystem that soft-starts freshly charged batteries upon connection. The device may be configured to operate on power from a number of batteries less than the greatest number of batteries that may be concurrently connected. Because the soft-start reduces current inrush upon connection of a fresh battery, the device may continue operating as fresh batteries are connected and depleted batteries are disconnected. ## Claims ### Claim 1 A power delivery system, comprising: a first battery connection; a first soft-start circuit connected to the first battery connection and a main power bus, wherein the first soft-start circuit is configured to: provide increasing levels of power to the main power bus when a first battery having a voltage level higher than a voltage level on the main power bus is connected to the first battery connection, and disconnect the first battery from the main power bus when the voltage level of the first battery is less than the voltage level on the main power bus; a second battery connection; and a second soft-start circuit connected to the second battery connection and the main power bus, the second soft-start circuit configured to throttle power from a second battery. ### Claim 2 (depends on 1) The power delivery system of claim 1, wherein the first soft-start circuit includes an output transistor, and a provision of power to the main power bus is through the output transistor. ### Claim 3 (depends on 2) The power delivery system of claim 2, wherein the output transistor is a field effect transistor, and a voltage at a gate of the output transistor is a function of a voltage at the first battery connection and a voltage at the main power bus. ### Claim 4 (depends on 3) The power delivery system of claim 3, wherein the first soft-start circuit further comprises an operational amplifier and a governance transistor, wherein the first battery connection is wired to a first input of the operational amplifier, the main power bus is wired to a second input of the operational amplifier, an output of the operational amplifier is wired to a gate of the governance transistor, and a drain of the governance transistor is wired to the gate of the output transistor. ### Claim 5 (depends on 4) The power delivery system of claim 4, wherein the gate of the output transistor and the first input of the operational amplifier are wired in parallel to the first battery connection. ### Claim 6 (depends on 4) The power delivery system of claim 4, wherein the output transistor is an n-channel transistor and the governance transistor is a p-channel transistor. ### Claim 7 (depends on 1) The power delivery system of claim 1, wherein the first soft-start circuit and the second soft-start circuit are both controlled by an integrated circuit. ### Claim 8 (depends on 1) The power delivery system of claim 1, wherein the first battery includes a gas gauge configured to measure a charge of the first battery. ### Claim 9 A power delivery system, comprising: a first soft-start circuit; a second soft-start circuit; and an integrated circuit configured to execute instructions that cause the first soft-start circuit to throttle power from a first battery connected to the first soft-start circuit or throttle power from a second battery connected to the second soft-start circuit, the first soft-start circuit configured to allow the first battery to remain connected until a difference or ratio between a power bus voltage and a voltage of the first battery reaches a threshold. ### Claim 10 (depends on 9) The power delivery system of claim 9, further comprising a gas gauge associated with the first battery, the integrated circuit is further configured to monitor the gas gauge for a governance of a current draw from the first battery. ### Claim 11 (depends on 9) The power delivery system of claim 9, wherein the integrated circuit is configured to send an error message to an output device if the voltage of the first battery is below a predefined threshold. ### Claim 12 (depends on 9) The power delivery system of claim 9, wherein the instructions, when executed, will further cause the integrated circuit to decrease a restriction of current draw as time elapses after connection of the first battery. ### Claim 13 (depends on 12) The power delivery system of claim 12, wherein the instructions, when executed, will further cause the integrated circuit to decrease the restriction of the current draw gradually. ### Claim 14 (depends on 9) The power delivery system of claim 9, wherein the power from the first battery is restricted in response to the voltage of the first battery exceeding a predefined threshold. ### Claim 15 (depends on 9) The power delivery system of claim 9, wherein the power is restricted based on a difference between the voltage of the first battery and a threshold voltage of the second battery. ### Claim 16 An electronic device, comprising: a power delivery system, the power delivery system including: a first soft-start circuit, and a second soft-start circuit; and an integrated circuit configured to execute instructions that cause the first soft-start circuit to restrict power from a first battery connected to the first soft-start circuit or restrict the power from a second battery connected to the second soft-start circuit, the first soft-start circuit including an operational amplifier having a first input connected to the first battery and having a second input connected to a main power bus. ### Claim 17 (depends on 16) The electronic device of claim 16, the electronic device being a wearable smart glasses device. ### Claim 18 (depends on 17) The electronic device of claim 17, comprising a temple for wearing the electronic device on a head of a user, wherein the temple includes a temple tip including at least the first battery. ### Claim 19 (depends on 18) The electronic device of claim 18, wherein the temple tip is removable from the electronic device.