Abstract: There is provided apparatuses and methods for measuring at least one thermal property of a body. The methods involve causing a symmetrical thermal boundary condition across the body such that measurements taken are not affected by the structure of the body being measured.

Abstract: There is provided a method and system for monitoring the condition of one or more cells within an electrochemical energy storage device. The electrochemical device is operated at a current comprising a predefined time-varying component for a first period of time. Voltage across and a measure of heat generation for each of the plurality of cells is sensed during the first time period. An estimate is then calculated of the open circuit potential of the electrochemical storage device from the predefined time varying component of the current and the sensed voltage during the first time period. Then, for each cell, a function can be calculated which relates a ratio of the time derivatives of the sensed measure of heat generation and voltage to the open circuit potential. From this, a measure of the state of health for each cell can be determined.

Abstract: An apparatus for supplying electrical energy to a varying load is disclosed. The apparatus comprises fuel cells and energy storage devices. A fuel cell subset comprises one or a plurality of series-connected ones of the fuel cells, having a first no-load open-circuit potential thereacross and is connected in parallel with an energy storage device subset comprising one or a plurality of series-connected ones of the energy storage devices, having a second no-load open-circuit potential thereacross, to form a unit. The unit cell is connected in series or parallel with at least one other unit cell. The fuel cells in the unit cell and the at least one other unit cell are fuel cells of the same fuel cell stack. The arrangement is such that first no-load open-circuit potential and the second no-load open circuit potential are substantially balanced.

Abstract: A method of operating a drive train for a hybrid electric vehicle, and a drive train, is disclosed. The drive train includes an internal combustion engine, a first electrical machine and electrical energy storage. The engine is coupled to drive the first electrical machine as a generator and the first electrical machine connected to supply electrical energy to the electrical energy storage. The electrical energy storage is arranged for supplying electrical energy to at least a second electrical machine for driving wheels of a hybrid electric vehicle. The method includes sensing a parameter indicating the voltage across the electrical energy storage and, in response to this sensed parameter, controlling the internal combustion engine and/or the first electrical machine such that the first electrical machine gives rise to a voltage output of the first electrical machine such that the electrical energy storage is charged without the need for power electronics.

Abstract: A method of operating a drive train (110) for a hybrid electric vehicle, and a drive train, is disclosed. The drive train comprises an internal combustion engine (120), a first electrical machine (130) and electrical energy storage means (150). The internal combustion engine is coupled to drive the first electrical machine as a generator and the first electrical machine connected to supply electrical energy to the electrical energy storage means. The electrical energy storage means is arranged for supplying electrical energy to at least a second electrical machine (170) for driving wheels (180) of a hybrid electric vehicle.

Abstract: A method for monitoring the condition of at least one cell of a battery, used in an electric or hybrid electric vehicle. The battery is connected to a power converter to supply electrical power to an electrical load. The method includes the steps of: controlling the power converter to vary the input impedance of the power converter to draw a varying current from the cell; sensing the voltage across the cell and the current drawn in response to varying the impedance of the power converter; calculating from the sensed voltage and current the complex impedance of the cell; and comparing the calculated complex impedance with information indicative of a correlation between (i) the complex impedance and (ii) information indicative of the condition of the cell, to give an indication of the condition of the cell. The varying current may be actively varied or passively varied.