Motorola Solutions, Inc.

Donald L Flowers

Robert L Snyder

Frederick J Weissinger

Viranga L Wijeratne

John E Herrmann

Charles William Friedli

Warren B Albert

John Alexander Herrmann

Bradley E Long

Roger L Boyer

Ryan Baker

Cindy P Cao

Muhamad Ridzuan Bin Azizan

Methods and apparatus for detecting open circuit fault conditions in a battery pack containing parallel cells include providing a first control signal to a close FET in parallel with a resistive element, the resistive element being in series with a first battery cell in a first cell path between the terminals of the battery pack, the first cell path being in parallel with a second cell path including a second battery cell. While the FET is closed, a test load is applied across the terminals and a first voltage measurement is obtained at a test point in the battery pack. The methods include providing a second control signal to open the FET, applying the test load across the terminals, obtaining a second voltage measurement at the test point, and determining whether a difference between the first and second voltage measurements indicates an open circuit fault condition in the battery pack.

Methods and apparatus for detecting open circuit faults in a battery pack containing parallel cells

Methods and apparatus for controlling charge current in a battery pack containing cells of disparate types are disclosed. The methods include receiving a charge current for charging a battery pack that includes one or more battery cells of a first cell type, and one or more battery cells of a second cell type. Each battery cell of the first cell type has a first impedance and a first charge current limit. Each battery cell of the second cell type has a second impedance greater than the first impedance and a second charge current limit greater than the first charge current limit. The methods include reducing, by a respective current control circuit associated with each battery cell of the first cell type, the amount of the received charge current through the battery cell of the first cell type to an amount less than the first charge current limit.

Methods and apparatus for controlling charge current in a battery pack containing cells of disparate types

Methods and apparatus for extending discharge over-current trip time in a battery protection circuit are disclosed. The protection circuit includes a safety circuit that asserts a first discharge over-current indicator when the discharge current of the battery exceeds a first discharge over-current threshold corresponding to a sustained over-current limit, a delay circuit that applies an added delay to the assertion of the first discharge over-current indicator, and a short circuit detection circuit that asserts a second discharge over-current indicator, with no delay added, when the discharge current exceeds a second discharge over-current threshold corresponding to a cell-specific peak output current limit. The battery protection circuit includes a logic circuit configured to assert a discharge over-current control signal to disable the battery responsive to assertion of the first discharge over-current indicator or the second discharge over-current indicator.

Methods and apparatus for extending discharge over-current trip time in a battery protection circuit

Methods and apparatus for a protection circuit for a battery and a battery connected device during charging are provided. In one embodiment, the apparatus includes a load-blocking switch connected between a rechargeable battery and an electronic device and a charge-blocking switch connected between the rechargeable battery and a charger. The apparatus also includes a safety circuit to detect a voltage across and the current flowing through the rechargeable battery. The safety circuit opens the load-blocking switch and the charge-blocking switch when it detects that the voltage across or the current flowing through the battery exceeds a predetermined threshold.

Load side method of blocking charger voltage from a battery load

Embodiments include a portable rechargeable battery pack, system, and external adapter that allow the portable rechargeable battery pack to both power a host device though a set of host contacts and provide power through a set of charging contacts. The portable rechargeable battery pack includes a charge protection circuit that prevents an excessive discharge current through the charging contacts and allows high charge current when charging the portable rechargeable battery pack. A discharge circuit allows a low level discharge current through the charging contacts to provide power to other devices.

Portable rechargeable battery pack and external adapter for same

A method and apparatus for multiplexing an electrical contact interface between two electrical devices uses a time differentiated enablement of two or more different circuit elements in a first electrical device that are accessed via the multiplexed contact by a second electrical device. A timing control circuit in the first electrical device enables and disables circuit elements in the first electrical device coupled to a shared information contact over time. The second electrical device interacts with a first circuit element during an initial period upon connection to the first electrical device, and then interacts with a second circuit element after the initial period.

Method and apparatus for a multiplexed contact between electrical devices

An apparatus for minimizing self-discharge of a smart battery pack is provided. During initial storage of the smart battery pack (), prior to be being charged, a self-discharge protection circuit () disables smart battery circuitry (). A minimal current drain is maintained while the smart battery circuitry () is disabled. Upon coupling of the smart battery pack () to a charger, the protections circuit () enables the smart battery circuitry (). Battery packs having to be shipped with partially drained cells as part of shipping precaution requirements are no longer faced with the additional drainage problem previously caused by the smart battery circuitry () during storage.

Growing community of inventors

Dacula, GA, United States of America

Donald L Flowers