Abstract: An energy storage system for a vehicle includes an ultracapacitor that is electrically coupled in parallel with a battery through a diode connected in series with the battery. The ultracapacitor delivers the energy required for all high current surges that occur during engine start, acceleration, and regeneration. The battery is used only to assist with longer duration, high energy loads, such as accessory loads when an engine of the vehicle is not running. In other words, the battery conducts only during longer and less-frequent pulses and, therefore, does not have to withstand high-power pulses.

Abstract: A circuit for charging a battery combined with a capacitor includes a power supply adapted to be connected to the capacitor, and the battery. The circuit includes an electronic switch connected to the power supply. The electronic switch is responsive to switch between a conducting state to allow current and a non-conducting state to prevent current flow. The circuit includes a control device connected to the switch and is operable to generate a control signal to continuously switch the electronic switch between the conducting and non-conducting states to charge the battery.

Abstract: A circuit and method are provided for allowing self-heating of a battery used to power an AC motor by way of connection to a DC to AC inverter circuit. The inverter is selectively controlled to generate a heating mode AC current at the DC side connection to the battery, wherein the heating mode AC current is formed substantially of only a reactive AC current component and substantially no DC current component. In accordance with another aspect, the heating mode AC current is generated to fill the idle time in the operation of the battery.

Abstract: An apparatus connected to an energy storage device for powering an electric motor and optionally providing a warming function for the energy storage device is disclosed. The apparatus includes a circuit connected to the electric motor and the energy storage device for generating a current. The apparatus also includes a switching device operably associated with the circuit for selectively directing the current to one of the electric motor and the energy storage device.

Abstract: An electronic circuit for measuring voltage signals in an energy storage device is disclosed. The circuit includes a plurality of battery segments forming the energy storage device. An amplifier circuit is connected across one of the battery segments for converting a differential voltage to a reference current. A sense resistor is associated with the amplifier circuit to convert the reference current to a voltage signal which is proportional to the voltage across the battery segment. A voltage measurement node associated with the sensing resistor may be used for measuring the voltage signal. In one embodiment of the invention, a multiplexing and sampling circuit provides digitized voltage samples to a processor. The voltage level of each cell within the battery pack can then be monitored by the processor.

Abstract: An electronic circuit for measuring voltage signals in an energy storage device is disclosed. The circuit includes a plurality of battery segments forming the energy storage device. An amplifier circuit is connected across one of the battery segments for converting a differential voltage to a reference current. A sense resistor is associated with the amplifier circuit to convert the reference current to a voltage signal which is proportional to the voltage across the battery segment. A voltage measurement node associated with the sensing resistor may be used for measuring the voltage signal. In one embodiment of the invention, a multiplexing and sampling circuit provides digitized voltage samples to a processor. The voltage level of each cell within the battery pack can then be monitored by the processor.

Abstract: A circuit for heating energy storage devices such as batteries is provided. The circuit includes a pair of switches connected in a half-bridge configuration. Unidirectional current conduction devices are connected in parallel with each switch. A series resonant element for storing energy is connected from the energy storage device to the pair of switches. An energy storage device for intermediate storage of energy is connected in a loop with the series resonant element and one of the switches. The energy storage device which is being heated is connected in a loop with the series resonant element and the other switch. Energy from the heated energy storage device is transferred to the switched network and then recirculated back to the battery. The flow of energy through the battery causes internal power dissipation due to electrical to chemical conversion inefficiencies. The dissipated power causes the internal temperature of the battery to increase.

Abstract: An electronic circuit for measuring voltage signals in an energy storage device is disclosed. The electronic circuit includes a plurality of energy storage cells forming the energy storage device. A voltage divider circuit is connected to at least one of the energy storage cells. A current regulating circuit is provided for regulating the current through the voltage divider circuit. A voltage measurement node is associated with the voltage divider circuit for producing a voltage signal which is proportional to the voltage across the energy storage cell.

Abstract: An energy management system for monitoring an energy storage device is disclosed. The energy management system includes a plurality of cells forming the energy storage device. Each of the cells includes a line for communicating a voltage signal. A local module is connected to the cells of the energy storage device. The local module has a plurality of inputs for receiving the voltage signals generated by the cells. The local module provides a multiplexed output signal. A processor is provided for receiving the multiplexed output signal from the local module and monitoring the voltage signals produced by the energy storage device.

Abstract: A circuit for heating an energy storage device is disclosed. The circuit includes a switching device having a closed state and an open state. The circuit also includes a storage circuit for storing energy. The storage circuit has a resonating frequency. A controller is provided for operating the switching device. In operation, energy is transferred from the energy storage device to the storage circuit while the switching device is in the open state, and returned from the storage circuit to the energy storage device while the switching device is in the closed state. This energy transfer causes warming of the energy storage device.

Abstract: A circuit for heating energy storage devices such as batteries is provided. The circuit includes a pair of switches connected in a half-bridge configuration. Unidirectional current conduction devices are connected in parallel with each switch. A series resonant element for storing energy is connected from the energy storage device to the pair of switches. An energy storage device for intermediate storage of energy is connected in a loop with the series resonant element and one of the switches. The energy storage device which is being heated is connected in a loop with the series resonant element and the other switch. Energy from the heated energy storage device is transferred to the switched network and then recirculated back to the battery. The flow of energy through the battery causes internal power dissipation due to electrical to chemical conversion inefficiencies. The dissipated power causes the internal temperature of the battery to increase.

Abstract: A shielded magnetic assembly for use in a magnetic hearing aid is described. The shielded assembly uses a disc-shaped magnet with a high permeability, low coercivity material placed on the face of the magnet away from the air gap. Preferably, the shielding material also covers portions of the edge of the magnet to form a cap. The shielding focuses the magnet's energy into the air gap to improve coupling and reduce interference from external magnetic fields.