A method of diagnosing malfunctioning of a bypass diode in a solar photovoltaic battery system is provided. The method may include: collecting solar photovoltaic battery operation information indicating a solar photovoltaic battery operation state, from a signal of a solar photovoltaic battery detection unit, while maximum power point tracking control is performed with the solar photovoltaic battery system in operation; and determining whether or not the bypass diodes based on the collected solar photovoltaic battery operation information.

A management device 50 for power storage elements is provided with a cause analysis unit 51 that, when the voltages of power storage elements B1-B4 are reduced to a prescribed level or physical quantities correlated with the voltages are reduced to prescribed values after the supply of power to the power storage elements B1-B4 has been stopped, analyzes the cause of the voltage reduction in power storage elements B1-B4 or the cause of the reduction in the physical quantities correlated with voltages to the prescribed values, on the basis of measurement data of the power storage elements B1-B4 measured after the supply of power has been stopped.

A management device 50 for power storage elements is provided with a cause analysis unit 51 that, when the voltages of power storage elements B1-B4 are reduced to a prescribed level or physical quantities correlated with the voltages are reduced to prescribed values after the supply of power to the power storage elements B1-B4 has been stopped, analyzes the cause of the voltage reduction in power storage elements B1-B4 or the cause of the reduction in the physical quantities correlated with voltages to the prescribed values, on the basis of measurement data of the power storage elements B1-B4 measured after the supply of power has been stopped.

Methods and electronic devices for estimating state of charge (SOC) of a battery pack. Various embodiments provide a model comprising an (electrical) equivalent circuit model, an electrochemical (thermal) model, and a (convective) thermal model. The model estimates parameters pertaining to each cell of the battery pack individually, and determines the variations in the values of the parameters among each of the cells of the battery pack. The parameters include capacity, temperature current, voltage, and SOC. The parameters are computed based on at current drawn by the battery pack, electrochemical parameters, thermal parameters, and cell internal and connection resistances of the individual cells. Various embodiments compute battery pack uptime, chargeable capacity of the battery pack and SOC of the battery pack, based on the values of the parameters.

A method for predicting an electric load imparted on each battery unit in an electric energy storage system comprising at least two battery units electrically connected in parallel to each other. The method comprises establishing a battery parameter set, the battery parameter set comprising at least the following values for each battery unit in the electric energy storage system: an internal ohmic resistance value indicative of the internal ohmic resistance of the battery unit and an open circuit voltage value indicative of the open circuit voltage of the battery unit, using an electric load level indicative of a total electric energy storage system load, and using the electric load level and the battery parameter set for predicting the imparted load on each battery unit in the electric energy storage system.

The present invention provides a power supply method and system for a hydrogen fuel cell stack, and a hydrogen powered motorcycle and a driving method and system thereof, the power supply method includes: a control chip detecting the operating states of the hydrogen fuel cell stack and the lithium battery pack; when the hydrogen fuel cell stack and the lithium battery pack are free of faults, obtaining the output voltage of the lithium battery pack; when the output voltage is lower than the charge-on threshold, the hydrogen fuel cell stack powering the lithium battery pack; when the output voltage is higher than the charge-stop threshold, disconnecting the circuit of the hydrogen fuel cell stack powering the lithium battery pack, when the output voltage is more than or equal to the charge-on threshold and less than or equal to the charge-stop threshold, the circuit of the hydrogen fuel cell stack remaining to power the lithium battery pack; and when the output voltage is higher than the charge-stop threshold, disconnecting the circuit oi the hydrogen fuel cell stack powering the lithium battery pack. The aforementioned technical solution uses hydrogen energy as the electrical energy powering the motorcycle as much as possible under the protection of the hydrogen fuel cell stack.

The present invention provides a power supply method and system for a hydrogen fuel cell stack, and a hydrogen powered motorcycle and a driving method and system thereof, the power supply method includes: a control chip detecting the operating states of the hydrogen fuel cell stack and the lithium battery pack; when the hydrogen fuel cell stack and the lithium battery pack are free of faults, obtaining the output voltage of the lithium battery pack; when the output voltage is lower than the charge-on threshold, the hydrogen fuel cell stack powering the lithium battery pack; when the output voltage is higher than the charge-stop threshold, disconnecting the circuit of the hydrogen fuel cell stack powering the lithium battery pack, when the output voltage is more than or equal to the charge-on threshold and less than or equal to the charge-stop threshold, the circuit of the hydrogen fuel cell stack remaining to power the lithium battery pack; and when the output voltage is higher than the charge-stop threshold, disconnecting the circuit oi the hydrogen fuel cell stack powering the lithium battery pack. The aforementioned technical solution uses hydrogen energy as the electrical energy powering the motorcycle as much as possible under the protection of the hydrogen fuel cell stack.

A method for charging a cell of an electric energy store includes setting the cell into a charging mode; determining a first and a second impedance characteristic, each representative of a complex alternating current impedance of the cell; determining a first and a second temperature characteristic on the basis of the impedance characteristics, each representative of a temperature of the cell; determining a deviation in the temperature characteristics; and reducing a charging current of the cell in the event that the deviation exceeds a specified temperature threshold value.

A method for controlling a lower limit of a state-of-charge state of a power battery, and a vehicle are provided, the method includes: detecting, by a detection unit, a minimum ambient temperature and a minimum power battery temperature in at least one time period; evaluating, by an evaluation unit, a minimum power battery temperature in a preset time period after the at least one time period according to the minimum ambient temperature and the minimum power battery temperature in the at least one time period; determining, by a processing unit, a minimum state-of-charge value that meets a start-up power requirement of a vehicle engine at the minimum power battery temperature in the preset time period, and adjusting a lower limit value of the state-of-charge according to the minimum state-of-charge value, in order that the vehicle can be powered-up by a state-of-charge value of the power battery at low temperature environment.

A battery control apparatus for a battery system includes: a first operation unit that computes a first state of charge of a battery according to a first technique on the basis of an electric current value, a voltage value, and an internal resistance value of the battery; a second operation unit that computes a second state of charge of the battery according to a second technique different from the first technique; and a correction unit that corrects the internal resistance value of the battery. if a difference equal to or more than a specified value is detected between the first state of charge and the second state of charge, the correction unit corrects the internal resistance value of the battery with a resistance correction amount according to the difference and the electric current value.