Patent Application
20220080855
The present disclosure relates to methods, devices, systems, and computer-readable media for calculating a battery lifetime of an electric vehicle.
A lifetime of a battery is the operation time before the battery's capacity drops below a threshold value. The battery lifetime can be predicted by assuming an expected battery use. Currently, many manufacturers calculate battery lifetime based on testing done in laboratory conditions under repeating current profiles and constant temperatures. This testing does not always reflect battery lifetime when operated in certain driving conditions.
A need for a more accurate battery lifetime prediction is increasing due to the increase in number of electric and/or hybrid vehicles in use. The battery lifetime prediction can assist in planning battery servicing and replacement. The battery lifetime prediction can also be used to assess residual (e.g., market) value of a battery.
The state of health (SoH) is an indicator commonly used to capture actual battery health in the electric vehicle industry. The SoH is a percentage ratio of the actual to the nominal battery capacity. However, the SoH gives limited insight into the remaining battery lifetime because it captures the actual battery capacity, but it does not indicate how heavily the battery was used or even misused. For example, the battery can be misused if the battery is operated out of the temperature specification range and/or if the battery is overcharged. This misuse can lead to a shorter battery lifetime.
A battery lifetime of an electric vehicle can be calculated according to embodiments of the present disclosure. For example, in some embodiments, the lifetime of the battery can be calculated by a network computing device based on actual battery use data of a specific electric vehicle, expected battery use data, and battery use data collected from one or more network connected electric vehicles.
In various embodiments, each of the electric vehicles can be powered by one or more batteries and can have one or more sensors for collecting the battery use data. A wide area network can connect the one or more network connected electric vehicles to a database which is used to collect the data for analysis.
A processor at a network device can be configured to execute instructions to send data from one or more electric vehicles to the database. In various embodiments, the one or more electric vehicles can send the data continuously, after a particular distance traveled, and/or after a particular battery charge throughput, for example.
Within the vehicle, the battery use data can be sent, for example, from a battery management system (BMS) in each of the one or more electric vehicles to the database. In some embodiments, a processor and memory can be in the vehicle and the database in memory can send the battery use data to a network computing device for analysis. In some examples, the battery use data can be sent as one or more histograms.
Devices, methods, systems, and computer-readable media for calculating a battery lifetime of an electric vehicle are described herein. One or more embodiments include using actual battery use data to calculate the lifetime of the battery. The actual battery use data can be data from the battery whose battery lifetime is being calculated. For example, the actual battery use data can be from a specific electric vehicle.
The actual battery use data can include state of health data of the specific battery. The state of health data can be a percentage ratio of the actual battery capacity over the nominal battery capacity. In some examples, the actual battery use data can also include state of charge, charge throughput, current amplitude, time duration, and temperature data.
As discussed above, in some embodiments, the battery use data can be contained in battery histograms, for example. The actual battery use data can be in an actual battery use histogram, the expected battery use data can be in an expected battery use histogram, and/or the battery use data from the one or more network connected electric vehicles can be in battery use histograms.
As discussed in more detail below, in some embodiments, the histograms used for analysis can include operation histograms and/or storage histograms. In some implementations, histograms can be useful in reducing the amount of data passed through the network which reduces the load on the network's bandwidth.
The expected battery use data, the actual battery use data, and the battery use data from the one or more network connected electric vehicles described herein can be utilized, for example, to calculate a capacity degradation of a battery. In some examples, the capacity degradation of a battery can otherwise be known as state of health (SoH) of a battery. The SoH is a percentage ratio of the actual to the nominal battery capacity.
The SoH of a battery can be calculated by interpolating an actual battery use histogram derived from actual battery use data. The SoH can be used to calculate the lifetime of the battery by, for example, combining an actual battery use histogram and an expected battery use histogram and estimating a period of time after which a predicted battery SoH reaches a threshold value.
In the following detailed description, reference is made to the accompanying drawings that form a part hereof. The drawings show by way of illustration how one or more embodiments of the disclosure may be practiced.
These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice one or more embodiments of this disclosure. It is to be understood that other embodiments may be utilized and that process changes may be made without departing from the scope of the present disclosure.
As will be appreciated, elements shown in the various embodiments herein can be added, exchanged, combined, and/or eliminated so as to provide a number of additional embodiments of the present disclosure. The proportion and the relative scale of the elements provided in the figures are intended to illustrate the embodiments of the present disclosure and should not be taken in a limiting sense.
The figures herein follow a numbering convention in which the first digit corresponds to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar remaining digits.
As used herein, “a” or “a number of” something can refer to one or more such things. For example, “a number of devices” can refer to one or more devices. Additionally, the designator “N”, as used herein, particularly with respect to reference numerals in the drawings, indicates that a number of the particular feature so designated can be included with a number of embodiments of the present disclosure.
The one or more electric vehicles 102-1, 102-2 can be powered by one or more batteries 104-1, 104-2. The one or more electric vehicles 102-1, 102-2 can include one or more sensors 103-1, 103-2 for collecting battery use data.
The one or more electric vehicles 102-1, 102-2 can also include battery management systems 106-1, 106-2. The battery management systems 106-1, 106-2 can collect and send the battery use data to the database 108.
As discussed above, the battery use data can be sent from the one or more of the electric vehicles 102-1, 102-2 after a particular distance traveled by the one or more electric vehicles 102-1, 102-2. The data can also be sent from one or more electric vehicles 102-1, 102-2 after a particular battery charge throughput of the one or more batteries 104-1, 104-2, or continuously communicated, in some embodiments. In some examples, the battery use data can be collected during vehicle servicing.
The battery use data can include state of health data of the one or more batteries 104-1, 104-2. The state of health data of a battery can be a percentage ratio of an actual battery capacity over a nominal battery capacity. The battery use data can be organized in histograms 110-1, . . . , 110-4. For example, the histograms 110-1, . . . , 110-4 can be operation and/or storage histograms.
The database 108 can receive battery use data from the one or more network connected electric vehicles 102-1, 102-2. The battery use data from the database 108 can be used to calculate a lifetime of a battery.
The battery use data from the database 108 can also be used to calculate capacity degradation of the battery. In some examples, actual battery use data from the specific battery and the expected battery use data can be used with the battery use data to calculate the lifetime of the battery and/or the capacity degradation of the battery.
The current amplitude 214 is the current in amperes that a battery of an electric vehicle is operating in. The temperature 222 is the temperature in Celsius that a battery of an electric vehicle is operating in.
The state of charge 216 is a current percentage of charge the battery of the electric vehicle has left. For example, the units of state of charge are percentage points, where 0% can indicate the battery is empty and 100% can indicate the battery is full. The charge throughput in Ampere-hour (Ah) is the charge throughput by the battery of the electric vehicle and indicates the energy that is delivered or stored by the battery of the electric vehicle.
In some examples, the current amplitude 214, temperature 222, state of charge 216, and the charge throughput 218 data can be collected using one or more sensors (e.g., sensors 103-1, 103-2 in
The battery use data can be sent from the one or more electric vehicles after a particular distance traveled by the one or more electric vehicles. The data can also be sent from the one or more electric vehicles after a particular battery charge throughput of the one or batteries is reached. In some implementations, sending data after a particular distance and/or after a particular battery charge throughput can be useful in reducing the amount of data passed through the wide area network (e.g., wide area network 100 in
In some examples, the network computing device can receive the battery use data from the one or more electric vehicles (e.g., electric vehicles 102-1, 102-2 in
The battery use data can be organized into an operation histogram 212 to reduce the amount of data passed through the wide area network (e.g., wide area network 100 in
An operation histogram 212 can be created with battery use data on an electric vehicle. In some examples, the operation histogram 212 can be used to calculate the state of health of a battery.
The temperature 322 is the temperature (e.g., in Celsius) that a battery of an electric vehicle is operating in. The state of charge 316 is a current percentage of charge the battery of the electric vehicle has left.
For example, the units of state of charge are illustrated as percentage points, where 0% can indicate the battery is at a minimum charge (e.g., empty) and 100% can indicate the battery is at a maximum charge (e.g., full). The time duration 324 in hours is the amount of time the battery of the electric vehicle is operated in a particular temperature and state of charge.
In some examples, the temperature 322, the state of charge 316, and the time duration 324 data can be collected using one or more sensors (e.g., sensors 103-1, 103-2 in
The data can be sent from the one or more electric vehicles after a particular distance traveled by the one or more electric vehicles. The data can also be sent from the one or more electric vehicles after a particular battery charge throughput of the one or more electric vehicles is reached.
As discussed above, sending data after a particular distance and/or after a particular battery charge throughput can be useful in reducing the amount of data passed through the wide area network (e.g., wide area network 100 in
In some examples, a network computing device can receive, via the wide area network (e.g., wide area network 100 in
The battery use data can be organized in a storage histogram 320 to reduce the amount of data passed through the wide area network (e.g., wide area network 100 in
A storage histogram 320 can be created with battery use data on an electric vehicle. In some examples, the storage histogram 320 can be used to calculate the state of health of the battery.
An actual battery use histogram 432 can be created based on the collected battery use data from the battery 404 of the electric vehicle. The actual battery use data can include state of charge, charge throughput, current amplitude, time duration, and temperature data.
The actual battery use histogram 432 can be created to reduce the load on the wide area network's (e.g., wide area network 100 in
The current amplitude, state of charge, and charge throughput data can be included in an operation histogram (e.g., operation histogram 212 in
A histogram of expected battery use 434 can also be created based on a prediction of what the battery use of the electric vehicle will be in the future. The expected battery use data can include state of charge, charge throughput, current amplitude, time duration, and temperature data. For example, if the electric vehicle will be operated in a colder climate, the time duration the battery 404 will be exposed to a colder temperature range will be more than a vehicle in a warmer climate.
The expected battery use data can be organized into a histogram to reduce the amount of data passed through the wide area network (e.g., wide area network 100 in
A number of histograms 410-1, . . . , 410-4 can be created from one or more network connected electric vehicles (e.g., electric vehicles 102-1, 102-2 in
The number of histograms 410-1, . . . , 410-4 can be created and sent periodically to reduce the load on the wide area network's (e.g., wide area network 100 in
The one or more network connected electric vehicles (e.g., electric vehicles 102-1, 102-2 in
The network computing device 430 can calculate a lifetime prediction 436 of the battery 404. The lifetime prediction 436 can include calculating a SoH of the battery 404.
In some examples, the SoH of the battery 404 can be calculated by interpolating the actual battery use histogram 432 data. The interpolation can be done using the Gaussian Process Regression, for example. The SoH of the battery 404 can be calculated using the actual battery use histogram 432 derived from the battery use data from battery 404. Using the actual battery use histogram 432 derived from the battery use data from battery 404 can result in a more accurate SoH calculation and a more accurate lifetime prediction.
The network computing device 430 can calculate a lifetime prediction of the battery 404 using the SoH of the battery 404. The SoH can be used to calculate the lifetime of the battery 404 by combining an actual battery use histogram 432 and an expected battery use histogram 434 and estimating a period of time after which a predicted battery SoH reaches a threshold value.
In some examples, the SoH lifetime prediction 438 can be expressed as SoH(t)=f(Q(t0)+(t−t0)
In some examples, interpolating the combined histogram into the predicted SoH at the end of multiple run time periods can be used to calculate the SoH lifetime prediction 438. The future battery capacity degradation trajectory can be calculated using the SoH lifetime prediction 438.
The SoP is the maximum power the battery can release. The SoP over time can decrease. For example, the maximum acceleration of the battery can decrease faster as a result of overcharging and/or storing in particular temperature ranges. In some examples, the SoH, lifetime prediction, and/or the SoP can be used to optimize battery use to avoid rapid battery degradation.
In this manner the embodiments of the present disclosure allow actual battery life for a particular vehicle to be more accurately managed and estimated. This can be beneficial in more efficiently managing the lifetime of a battery and potentially allowing a vehicle user to better manage the timing of battery replacement, among other benefits.
Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same techniques can be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments of the disclosure.
It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description.
The scope of the various embodiments of the disclosure includes any other applications in which the above structures and methods are used. Therefore, the scope of various embodiments of the disclosure should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.
In the foregoing Detailed Description, various features are grouped together in example embodiments illustrated in the figures for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the disclosure require more features than are expressly recited in each claim.
Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
This application is a Continuation of U.S. application Ser. No. 15/953,211, filed Apr. 13, 2018, the contents of which are incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15953211 | Apr 2018 | US |
| Child | 17536965 | US |
