Honeywell International Inc.

Other

Alliedsignal Inc.

Steven Hoenig

Thirumalai G Palanisamy

Harmohan N Singh

Hector M Atehortua

Patrick M Rudai

Margaret Eagan

In accordance with various embodiments, there is a method for determining the state of charge of a battery. Various embodiments include the steps of determining the specific gravity of the battery and measuring an open circuit voltage of the battery at rest. The open circuit voltage at rest can be used to determine the battery state of charge from a correlation function dependent on the battery specific gravity.

Method for determining state of charge of lead-acid batteries of various specific gravities

In accordance with various embodiments, there is a method for determining the capacity of a battery. Various embodiments include applying a predetermined current ramp to a fully charged lead-acid battery while measuring a battery terminal voltage. An Ican be determined, where the Iis a transition from charging to overcharging. A specific gravity of the lead-acid battery can also be determined. The capacity of the lead-acid battery can then be determined from the Iusing a correlation function that describes the relationship of the Ito the capacity, where the correlation function depends on the specific gravity of the lead-acid battery.

Method for determining capacity of lead-acid batteries of various specific gravities

In accordance with the invention, there is a battery defect detection method comprising applying a current ramp to a battery; determining a first time (t) when a current of the battery reaches a maximum current (I), and determining a second time (t) when a terminal voltage of the battery reaches a maximum voltage (V). The method also includes determining a differential (d), wherein (d)=/(t)&#x2212;(t)/, and wherein (d) corresponds to a magnitude of defects in the battery.

Capacity degredation in a lead acid battery method and apparatus

In accordance with various embodiments, there is a method for determining the available energy of a battery. Various embodiments include the steps of applying an increasing current to the battery and measuring a response voltage of the battery when the increasing current is applied to the battery.

Method and apparatus for determining the available energy of a lithium ion battery

In accordance with various embodiments, there is a method for determining the specific gravity of a battery. Various embodiments include the steps of applying an increasing current ramp to a battery and measuring a response voltage of the battery when the increasing current ramp is applied to the battery. When the current ramp reaches a predetermined current a decreasing current is supplied to the battery and the battery's voltage response is measured. The specific gravity of the battery can be determined based on the voltage response of the battery to the applied current ramp.

Method and apparatus for automatic determination of lead-acid battery specific gravity

A method of predicting by non-invasive testing the available energy of a battery at any state of charge by acquiring data of the parameters of internal resistance (IR), open circuit voltage (OCV) and temperature (T), the points of voltage and current of the slope on a positive current ramp of V and I at the transition from charge to overcharge and on a negative current ramp of V and I at the transition from overcharge to charge for a plurality of batteries. Next an algorithm in the form of a linear equation is developed using this data. The available energy of a battery under test is predicted by acquiring from it the numerical data values of these parameters and applying them to the algorithm.

Method and apparatus for predicting the available energy of a battery

A method for determining the state of charge (SOC) of a battery by measuring its open circuit voltage (OCV) either with the battery in a fully rested state of chemical and electrical equilibrium or an active state during a period in which the battery settles after charge or discharge is stopped. A first type algorithm is developed to correlate the OCV in a fully rested condition (OCV ) to the state of charge at which that measurement is taken. A second type algorithm is developed that predicts a final settling OCV of a battery (OCV ), based on the set of parameters of OCV, rate of change of OCV, and battery case temperature, acquired during the settling period of a battery not at rest. To determine the SOC of a battery being tested that is in the fully settled state the measured OCV is applied to the first type algorithm. To determine the SOC of a battery that has not fully settled, the data of the OCV, rate of change of OCV and battery temperature is applied to a second type algorithm to determine OCV and the OCV value is used in the first type algorithm to determine SOC.

Method for determining state of charge of a battery by measuring its open circuit voltage

Deficiencies in the electrolyte level of the cells of NiCd battery can be detected by measuring the internal resistance of the cells. Initially, data is collected for a battery type and capacity, correlating measured internal resistance with the amount of water that must be added to bring the cell resistance to an acceptable value. Subsequently, cells of other batteries of the same type and capacity can be measured to determine how much water must be added and the levels quickly restored. The polarization value of the cells can be used lieu of the internal resistance in the same fashion.

Method for determining amount of water to be added to a NiCd cell

A method and apparatus for diagnosing the status of a battery having high and low voltage plateau states corresponding to its state of charge in which the battery open circuit voltage is measured (S,) to determine its voltage state and its internal resistance also is measured (S,). A battery having a low voltage state (S,) is tested to determine if its internal resistance is greater than a predetermined maximum resistance (S,) and if it does the battery is considered as possibly having a low electrolyte level, and if it does not the battery is subjected to a current ramp test to determine from the voltage response a point of current transition (S,) due to a battery chemical gassing reaction. The battery state of charge (S,) is determined from curves or algorithms of state of charge versus current transition. Each of a battery of high voltage state (S,) whose internal resistance is less than the maximum internal resistance and one whose internal resistance is greater than the maximum internal resistance and has been subjected to reconditioning by applying successive current pulses (S,, S,) to reduce its internal resistance is subjected to a current ramp test (S,) to determine the point of current transition and the state of charge of such battery is determined (S,) from a different set of curves or algorithms of state of charge versus current transition. Capacity of a battery of the two voltage state types is determined by charging it to its capacity (S,), applying a current ramp (S,) to determine the point of current transition and determining capacity from curves or algorithms of battery capacity versus current transition (S,).

Method and apparatus for analyzing an AgZn battery

A system and method for comprehensive analysis of a multi-cell battery, such as of the nickel-cadmium type, on an individual cell level basis and overall battery basis. For an unsealed battery, which affords access to the individual battery cells, (FIG. 2) tests are carried out to determine the presence of any shorted or reversed cells, and these can be repaired or replaced ((6)-(11)). The individual cells are then tested for sufficient electrolyte on the basis of comparing the cell internal resistance to a maximum internal resistance for the cell and electrolyte added as needed ((12)-(15)). A sealed battery, to which there is no access to the individual cells, is first tested for shorted or reversed cells on a battery level basis ((16)-(19)). A sealed battery that passes this test ((20)-(22)) and an unsealed battery whose individual cells have been found to be satisfactory in its prior tests are subjected to further testing on a battery level basis for: (a) overall internal resistance to determine if it exceeds a given maximum value internal resistance, this indicating that the battery is defective (23); and (b) actual capacity as compared to its rated capacity ((24)-(30)). A battery whose actual capacity is greater than its rated capacity is tested for a memory effect and the memory effect problem is corrected if found to be present ((31)-(36)).

Growing community of inventors

Staten Island, NY, United States of America

Steven Hoenig