Abstract: Methods and associated apparatus for testing an electrochemical device, such as a fuel cell. A first method involves charging the fuel cell during a charge period; discharging the fuel cell during a discharge period; and monitoring the response of the fuel cell during at least part of the discharge period or the open-circuit response of the fuel cell. Another method involves testing the fuel cell when the fuel cell is in a passive state in which substantially no electrochemical reactions are taking place in the fuel cell. simultaneously applying a stimulus to all of the devices, and independently monitoring the response of each of the devices to the stimulus. Further methods involve obtaining test data from a device being tested; obtaining equivalent circuit values; calculating sets of simulation data for each equivalent circuit value; comparing sets of simulation data with the test data; and selecting one of the equivalent circuit values based on the comparison.

Abstract: One or more cells are charged by measuring one or more cell parameters or changes in said cell parameters, inputting the measured cell parameter(s) or changes in cell parameters into a state of charge estimation model, obtaining a state of charge of the cell(s) from the state of charge estimation model, selecting an allowable temperature rise for the cell(s), determining a charge parameter in accordance with the state of charge of the cell(s) and in accordance with the selected allowable temperature rise for the cell(s), and supplying energy to the cell(s) in accordance with the determined charge parameter. The invention may be embodied as methods, apparatus and computer program products.

Abstract: The invention relates to a new VRLA battery float model. The model covers the steady state and transient float charge behavior of both positive and negative electrodes. Backup analysis verifies the internal polarization distribution for a conventional 2V-cell polarization behaviors can be identified without the need for a physical reference electrode. The estimated individual electrode polarization allows early detection of common failure modes like negative plate discharge as well as a reference for float voltage optimisation. Furthermore, the positive polarization relating to minimum grid corrosion may be correlated with the occurrence of the peak of a “Tafel” like resistance used by the model. The model encourages utilisation of low signal perturbation for testing a cell's state of health and state of charge conditions while at float.

Abstract: A battery management system includes a sensing module, a feeding module, a control module, and a common line adapted for connection to a battery when in use. In some embodiments, a battery management apparatus for managing a substring of cells in a string of cells includes a DC bus, a multiplexer/demultiplexer circuit operative to selectively couple nodes of the substring of cells to the DC bus, a DC/DC converter circuit having a first port configured to be coupled across a plurality of cells of the string and a second port coupled to the DC bus, the DC/DC converter operative to transfer energy between the first and second ports, a sensor circuit coupled to the DC bus, and a controller circuit configured to connect to a communications bus and operatively associated with the multiplexer/demultiplexer circuit, the DC/DC converter and the sensor circuit.

Abstract: A battery monitoring network including a battery node (6); one or more distributed nodes of a first class (4) each including means for acquiring first battery variable information, processing means adapted to manipulate the first battery variable information, and a communication means for communicating with a battery node; and one or more distributed nodes of a second class (5) each including means for acquiring second battery variable information, processing means adapted to manipulate the second battery variable information, and a communication means for communicating with the battery node.

Abstract: A method of battery monitoring including the steps of: acquiring a battery voltage measurement from the battery; and acquiring a time measurement associated with the battery voltage measurement. A scaled voltage value is determined by scaling the battery voltage measurement with respect to a start voltage and/or predetermined end voltage. A scaled time value is determined from the scaled voltage value in accordance with a predetermined battery characteristic. An absolute reserve time value is then obtained from the scaled time value, the reserve time being indicative of the difference between the time measurement and an end time associated with the predetermined end voltage.

Abstract: A model of battery reserve life that a function of a SOH indicator is adaptively modified responsive to intermittent capacity tests of a battery, e.g., based on reserve life estimates generated responsive to the capacity tests. The SOH indicator for the battery is monitored to generate SOH indicator values, and estimates of reserve life are generated from the generated SOH indicator values according to the adaptively modified model of reserve life. For example, a capacity test may be performed responsive to detection of a change in reserve life as estimated by the model of reserve life, and the model of reserve life may be modified responsive to the capacity test. The battery reserve life model may, for example, express reserve life as a function of a float voltage, a float current, a temperature, a charge/discharge cycling, an impedance, a conductance, a resistance, and/or a coup de fouet parameter. The invention may be embodied as methods, apparatus and computer program products.