TWI398658B - An instant calculation method for battery pack information for electric vehicle and electric vehicle using the method - Google Patents

Description

Instant calculation method for battery pack information of electric vehicle and electric vehicle using the same

The present invention relates to an information calculation method for an electric vehicle, and more particularly to a battery pack related information calculation method and an electric vehicle using the same.

For electric bicycles, electric locomotives, electric vehicles and other electric vehicles that drive the vehicle body in combination with power supply, the power source mainly includes a set of battery modules. According to the current technology, the mileage that can be driven after a single charge is comparable to that of the general Fuel and gas-driven vehicles are short, and there is also a lack of densely distributed fuel (gas) stations. However, in the environment of declining oil and gas stocks, rising prices, and increasing environmental awareness, the oil and gas-driven vehicle market is increasingly low, and electric vehicles are gradually becoming more and more It is attracting attention.

Since the electric vehicle has the trouble of the above-mentioned limited travel, the problem of traveling to the middle of the road without power is sometimes heard. Therefore, the existing industry has proposed to record the current magnitude, voltage and time when the electric vehicle is charged to obtain the total electric energy of charging and The total electrical energy of the discharge is used to estimate the remaining battery value of the battery in this way, and a warning is issued when the power is too low. The detection methods of the conventional methods are the ampere-hour method and the watt-hour method. In the general ampere-hour method, only the current and time of charging are recorded, and the amount of charge (Coulomb value) is accumulated. When discharging, the current magnitude and time are recorded, and the amount of discharge (Coulomb value) is accumulated, and the residual energy of the battery is accumulated. The value of the discharge energy is subtracted from the charging energy. In the ampere-hour method, the true electrical capacity of the battery due to the variation of the battery voltage is not the same as the estimated power, so that the accuracy is poor.

Then, the watt-hour method is evolved, and the total electric energy of the charging and the total electric energy of the electric discharge (watt-hour) are obtained by measuring the battery voltage, the charging and discharging current and the time of charging and discharging, thereby obtaining the remaining electric quantity of the battery. This method is certainly better than the previous amps - The hourly estimate is more accurate. However, the charging efficiency of the battery on the electric vehicle is not 100%. This value varies not only with different batteries, but also with the aging of the rechargeable battery, and is more likely to be affected by environmental factors. Therefore, it is estimated to be charged in the rechargeable battery. In the case of electrical energy, if the efficiency is 100%, the total electrical energy will deviate from the actual situation. Generally speaking, it is empirically chosen that the charging efficiency is between 80% and 90%, but this value has no objective and quantitative scientific projections, and it is impossible to fully display the aging problem of the rechargeable battery.

In addition, during the discharge process, the discharge efficiency from the chemical energy stored in the battery to the output of the electric energy is also affected by various factors such as temperature and the environment of the battery itself, and even the aging of the battery, so that the discharge efficiency is not 100%, at present, it is generally based on experience to choose a hypothetical value, there is no objective and quantitative calculation process, and it is also impossible to respond to the actual situation in real time in response to the aging of the battery.

Furthermore, even if it is not used, it will self-discharge due to internal chemical reactions and reduce residual energy. The self-discharge rate will vary from battery to battery, and may range from 10 to 20% per month. For a battery that is charged to saturation every day, this error is only within 1% of the total energy, with little effect. However, if a user only charges the battery to 80~90% every day, the self-discharge error cannot be reset and compensated, but will accumulate with the use time, the error will gradually expand, and the estimated remaining power will become increasingly distorted. There is no objective and quantitative method for calculating this power loss.

1 and 2 are an electric vehicle 10 (herein shown as an electric vehicle) using a conventional electric vehicle electric quantity estimation system 20, the estimation system 20 is disposed through a set of detection recorders. The physical and electrical changes of the battery module on the conventional electric vehicle 10 are monitored and monitored instantaneously, and the recorded data is transmitted to the remote monitoring center through the communication unit, and the monitoring center determines the residual of the battery module according to the data record. Whether the power is insufficient or abnormal, and wireless transmission through telecommunication equipment Sending a signal, for example, transmitting a short message of insufficient power to a predetermined mobile phone of a pre-registered person by using a mobile phone short message to remind the driver of the state of charge, thereby maintaining the safety of the driver.

However, the above estimation system 20 not only needs to set a communication interface on the vehicle, but also relies on a densely distributed base station as a communication bridge to transmit and receive signals, and must also have a remote monitoring center to process a large amount of data, and the entire system is not only costly. After being passed on to the purchaser of the electric vehicle 10, the market acceptance is inevitably lowered. Moreover, the remote monitoring center undertakes a large amount of data to be processed, and it is necessary to try to ensure that the sent warning signals are not missed; in particular, such processing is extremely difficult to charge, and involves personal privacy, which undoubtedly adds difficulty to practical use.

In other words, the current electric vehicle industry urgently needs a method that can roughly estimate the charging efficiency, discharge efficiency, power loss rate, and remaining power of the rechargeable battery, and the electric vehicle to which the method is applied, without unnecessary communication and other hardware cost. Using the factors such as the charging efficiency, discharge efficiency, battery system and vehicle power consumption rate of the obtained battery, calculate the correct remaining battery value of the battery to estimate the battery life and personal driving habits. Reference.

An object of the present invention is to provide a method for calculating battery power related information with a simple structure and limited resource consumption.

Another object of the present invention is to provide a calculation method that can accurately and objectively quantitatively calculate battery pack related information to obtain a correct state factor of a battery pack at any time.

Still another object of the present invention is to provide a method for quantitatively estimating charging efficiency variation, discharge efficiency, and battery system and vehicle leakage of a battery pack, while abnormality is found The calculation method of the battery pack related information when the police are alerted.

Still another object of the present invention is to provide an electric vehicle that estimates the distance it can travel in accordance with the electric vehicle's electric condition and the condition of the vehicle.

Therefore, the present invention discloses a battery pack related information calculation method, wherein the battery pack has a predetermined saturation state Ef, and the battery pack is electrically connected to a group of charging devices and a group of power consuming devices respectively, and the charging device inputs the battery pack. The electrical energy and the electrical energy output by the battery pack to the power consuming device can be measured by a group of detecting processing devices. The method includes the following steps: a) recording the time point when the battery pack reaches the predetermined saturation state Calculating the reference point t _{f1 for} a time; b) measuring, by the detecting processing device, the electrical energy input to and outputting the battery pack from the time calculation reference point t _f1 ; c) detecting whether the battery pack reaches the predetermined saturation again State Ef, if it is reached, calculate a time interval Tct from which the reference point t _{f1 is} calculated from the time to the predetermined saturation state Ef and another time to calculate the reference point t _f2 , and a time interval t _{D for} charging; d) calculating the power loss rate Pe that is not output to the power consuming device during the time interval according to the total input and output power during the time interval and the length of the time interval.

The present invention further discloses an instant calculation method for battery pack information of an electric vehicle, wherein the battery pack has a predetermined saturation state Ef and a predetermined low limit state Eb, and the battery pack is electrically connected to a group of charging devices and a group of power consumption devices respectively. The power input by the charging device to the battery pack and the power output by the battery pack to the power consuming device can be measured by a group of detecting processing devices, and the method comprises the following steps: h) reaching the battery pack When the predetermined saturation state or the predetermined low limit state is predetermined, the time point is recorded as a time calculation reference point t _start ; i) the detection processing device measures the input/output power of the battery pack from the time calculation reference point, and Each input/output time interval; j) detecting whether the battery pack reaches the predetermined saturation/lower limit state again, and whether the predetermined low limit/saturation state is reached, measuring and recording the first occurrence of the two The time calculation reference point t _middle and the time of the subsequent occurrence are calculated as a reference point t _end ; wherein at least one of the battery state states of the reference time calculation reference point is located Calculating the charging efficiency ε _C and/or discharging in the predetermined time interval according to the total input and output electrical energy in the time interval and the length of the time interval; Efficiency ε _D .

The above method may apply to an electric vehicle as described below, and the vehicle may be electrically connected to a set of charging devices to receive electrical energy input by the charging device, the electric vehicle comprising: a set of measuring the driving speed and/or distance of the electric vehicle a vehicle condition detecting device; a battery pack that supplies the electric vehicle with electric energy and can receive the electric energy input by the charging device and has a predetermined saturation state Ef; a group records the time when the battery pack reaches the predetermined saturation state as a time Calculating a reference point; measuring, from the reference point, the charging device inputs the battery pack and the electrical energy output by the battery pack; detecting the re-saturation timing of the battery pack again reaching the predetermined saturation state, and the re-saturation timing a time interval from the reference point; calculating, according to the total input/output power during the time interval and the length of the time interval, a power loss rate not supplied to the electric vehicle during the time interval; calculating the battery pack according to the power loss rate The remaining power; and according to the remaining battery capacity of the battery pack, and the output information of the vehicle condition detecting device, A detection processing device for estimating an endurance stroke of the electric vehicle; and a display device for displaying an endurance stroke estimated by the detection processing device.

The invention can accurately estimate the electric energy related information of the battery pack, calculate the endurance travel of the electric vehicle according to the remaining power of the battery pack and the detected driving condition, and express the driving information in a display manner convenient for the driving of the vehicle; The invention can further determine the power loss rate and the charge and discharge efficiency by the method, and objectively and quantitatively calculate Calculate the above battery pack correlation factor, so as to clearly know whether the electric vehicle needs to be repaired or the charging device with it has problems, which greatly improves the user's information correctness.

The foregoing and other objects, features, and advantages of the invention are set forth in the <RTIgt; For convenience of description, the electric vehicle in the battery unit related information calculation method of the present invention is exemplified by the electric motor vehicle shown in FIG. 3. Of course, other battery packs or other types of electric vehicles can also apply the electric quantity estimation disclosed in the present case. The method obtains the same data.

The lithium battery pack used in the general electric vehicle 10' is provided with a protection circuit board for protecting the battery pack, and the voltage of the battery pack is used as an index. For example, the saturation voltage of a battery cell can reach 4.2 volts, so when five batteries are connected in series When a single unit is used as a battery pack, the total saturation voltage will reach 21 volts, and when charged with a large current, each battery easily reaches a saturated voltage state and affects the charging efficiency; further, even if it is not used, the battery pack At any time, there is a small amount of leakage current, so that when charging, the charger will give the battery pack an incorrect amount of power, which will cause continuous damage to the battery pack for a long time. For the sake of explanation, referring to the first embodiment of the present invention shown in FIG. 4, the related configuration of the electric quantity related information calculation method of the electric vehicle 10' to which the present invention is applied is clarified, and the method electrically connects a group of charging devices 40. The battery pack 31 of the electric vehicle 10' is used for energy storage, and the power obtained by the battery pack 31 and the power output to the power consuming device 32 are monitored by a set of detecting processing devices 33, wherein the group consumes power. Device 32 represents all of the electrical energy-consuming components and lines within the electric vehicle 10'.

As shown in FIG. 5 and FIG. 6 and FIG. 7 , the method for calculating the power-related information in this example is recorded as a time calculation reference point when the detection processing device 33 detects that the battery unit 31 reaches a predetermined saturation state according to step 61. _F1 , the energy mark and the time mark are Ef and t=0, respectively, and are regarded as the initial state of the battery pack 31. According to step 62, the electric energy of the input and output battery packs is measured from tf1; 63 detects that the battery pack reaches the predetermined saturation state time tf2, calculates the time interval Tet from tf1 to tf2, and starts calculating the self-discharge and leakage of the electric vehicle 10' and the battery pack 31 through a clock signal control module 335 according to step 64. Loss, and the input/output current I _c , I _u and the input and output voltages V _c , V _{u of the} input and output of the battery 31 are measured by the voltage/current detector 332 from the time calculation reference point t _f1 . Because of the electric power P=V. I, so the controller 331 in the detection processing device 33 calculates the total output power when the time t is And total input power

For the sake of explanation, the charging and power consumption conditions from the time calculation reference point t _{f1 are} shown in FIG. 6 . For example, in the time period tu11 , since the power loss rate Pe is a known value measured before leaving the factory, the electric vehicle 10 'On the general road, the total power consumption of the battery pack 31 during this period = output power Eu11 + self-discharge and the overall leakage of the circuit slightly lost power Pe × tu11; then the electric vehicle 10' enters the mountain, so the output power of the period tu12 As Eu12 increases, the total power consumption slope is steeper; the period tu13 returns to a flat road, so the total power consumption slope recovery is the same as that of tu11.

After the above time, the user charges the battery pack 31 of the electric vehicle 10' to the charging device at the time period tc1. At this time, tu21 indicates that the electric vehicle 10' is neither charged nor traveled, and the factors affecting the battery pack 31 will only be The power loss of the sum of self-discharge and leakage is left, Pe×tu21; to the time period tu22, the electric vehicle 10' travels again on a flat road surface. Similarly, after the charging period of tc2 and tc3 and the period of tu31 and tu32, the voltage/current detector 332 measures that the battery pack 31 reaches the predetermined saturation state again, and defines this time as t _f2 .

The controller 331 accumulates and calculates the total input power Ect=Ec1+Ec2+Ec3 in the time interval Tet by the clock signal data of the clock signal control module 335, that is, the total charging energy, or , the actual energy stored in the battery pack 31, it is necessary to consider the charging efficiency ε _C measured before leaving the factory, but should be And calculate the total output energy Eut=Eu11+Eu12+Eu13+Eu22+Eu32 in the time interval Tet, that is, the total power consumption And rely on the rate of discharge efficiency ε _D before leaving the factory;

Substituting the total input and output power during the time interval, and the length of the time interval, calculating the power loss rate Pe that is not output to the power consuming device during the time interval. Therefore, the power loss rate Pe is substituted into the following power calculation formula according to step 65, and the remaining power amount at a certain time t from the calculation of the reference point t _f1 at any time when the battery pack 31 reaches the saturation state can be correctly obtained:

As described above, the present case not only accurately calculates the correct remaining power of the battery pack 31, but also supplements a vehicle condition detecting device 34, such as the vehicle speed and the motor turn. Speed and other general driving information, and assume that when other driving conditions such as the current wind, rain conditions, terrain conditions, tire pressure, load capacity and other conditions do not change drastically, it is estimated that the motor and the battery pack 31 are measured according to the foregoing measurements. Using the efficiency, the driving distance that the current residual power can provide is correctly evaluated and displayed on the display device 35 to prevent the driver from self-estimating the possibility of the remaining power error.

Referring to Figures 8 and 9, the figures are schematic diagrams of display devices in which the electric vehicle is in standby and the vehicle speed is estimated. In Fig. 8, the electric vehicle has not been started yet, and the driving speed and the travelable distance are not shown. As shown in FIG. 9, the electric vehicle detects the sufficient reference data by the vehicle condition detecting device for the detecting processing device to determine the influence of the current vehicle condition on the output power of the battery pack; therefore, the display device 35 dashboard The exact residual capacity of the electric vehicle is displayed on it.

By using the above-mentioned battery residual processor of the present invention, the residual energy ER of the current battery can be obtained, and if the voltage detector and the current detector in the vehicle controller are used, the instantaneous output voltage supplied from the battery pack to the vehicle is obtained. The value Vi and the current value Ii, then its input power Pi = Vi. Ii, the current travel speed V is obtained from the vehicle controller. If the current driving conditions are assumed, the residual energy ER of the battery can still travel (ER/Pi) time, so the distance travelable is: SR=ER/Pi. V

This information can also be presented on the display device, so that the driver can clearly know how long and how long it can travel under the current condition, without the driver's own rough estimate of the battery life. In addition, the values of the charging efficiency ε _C , the discharge efficiency ε _{D ,} and the power loss rate Pe can be used as a criterion for determining the performance of the battery and the condition of the vehicle circuit, in addition to calculating the residual power of the electric vehicle, when the charging efficiency or When the discharge efficiency is reduced to more than a predetermined standard, the detection control device can also provide a warning signal to remind the driver that the battery performance has deteriorated. It is necessary to perform "reactivation" of deep discharge and charging depending on the situation, or even to directly replace the new battery pack. When the power loss rate is too high, it is also necessary to repair the relevant circuits or components as necessary to avoid unnecessary leakage.

Further, according to step 66, when the battery pack 31 is used for a long period of time, the charging efficiency ε _C , the discharge efficiency ε _D or the power loss rate Pe may have different magnitudes of change, so that the charging efficiency ε _C or the discharging efficiency of the battery pack 31 ε _{D is} used as an unknown number; after a predetermined period of use, the electric vehicle uses the following input power, output power, and time interval length in the Tet interval:

By inputting the relevant data, a new current charging efficiency ε _C or a discharge efficiency ε _D can be obtained. And at the same time, the latest charging efficiency and discharge efficiency are substituted, and the latest power loss rate Pe can be calculated again in real time. Of course, three different time calculation points can be taken, and two of them are used as the starting and ending points of the integral to obtain a calculation formula; and one of the starting and ending points is replaced to obtain another calculation formula, and the two calculation formulas are combined. When standing, the charging efficiency ε _C and the discharge efficiency ε _D can be known at the same time.

The above calculation will be described with reference to Fig. 12 as shown in the embodiment of Figs. 10 and 11. The battery pack has a predetermined saturation state Ef and a predetermined low limit state Eb, and as in the previous example, the power input from the charging device and the power output from the battery pack to the power consuming device can be detected by the group detection processing device. As measured, the state of charge of the battery pack also changes.

In this example, in step 71, when the battery pack reaches the predetermined saturation state Ef once, the time point is recorded as the time calculation reference point t _start ', and step 72 is continued, after detecting that the battery pack subsequently reaches the predetermined low limit state Eb. Recording the reference point t _middle ' at this time, and measuring the time period Tet ₁ ' of the two points, and calculating the reference point t _end ' and the measurement time according to the time after the step 73 reaches the predetermined saturation state Ef again. Segment Tet ₂ '.

Since the new factory power loss rate Pe, charging power Ect', charging energy consumption t _C and power consumption Eut=Eu11'+Eu12'+Eu13' are known, step 74 can be selected in turn. The time calculation reference point t _start ', t _midd1e ', and t _end ', respectively, as t _f1 and t _f2 are substituted into the following equation, and one of them is changed and substituted into the following formula:

Since two independent equations can be obtained by calculating the reference points at three different times, it is possible to simultaneously solve two unknowns of charging efficiency and discharge efficiency.

Of course, as can be easily understood by those skilled in the art, the charging state of the battery pack in FIG. 10 is an example of full-use to low-recharge, but the calculation method of the present invention is not limited to this mode. As shown in FIG. 11, even after the battery pack reaches the predetermined saturation state Ef and is regarded as the time calculation reference point tstart", the electric energy is not always consumed to the low limit state, but is subjected to two different power consumption rates. After driving Eu11" and Eu12", after the charging process of Ec1", the reference point tmiddle" is recharged to saturation state, and after two different power consumption rates of Eu13" and Eu14", the reservation is reached. lower limit state Eb, is calculated and recorded as the reference point of time t end ", can likewise be substituted into the following formula:

For example, substitute t start" to t middle" In the formula, the molecular part mainly calculates the power loss of Eu11" and Eu12", and the denominator calculates the power loss of the Ec1" electric energy charging and Tet1" time. In addition, t midd1e" and t end" are also substituted into the same formula, the molecular part mainly calculates the energy loss of Eu13" and Eu14", and the denominator is the power loss of Tet2" time. The two equations can eliminate the same ε _D. The unique unknown ε _{C is} obtained; the ε _{C is} returned to the equation again, and the discharge efficiency ε _D can be solved synchronously. Therefore, all the data related to the battery performance and the calculated residual power can be calculated in real time.

Even adding a time point when the electric energy is in the saturated state or the low limit state, thereby increasing the third algorithm, and the synchronous solution includes three unknowns of charging efficiency, discharge efficiency and power loss rate. Especially in actual discharge, the discharge efficiency is more likely to be a function of the current amount I. Although the amount of change is limited, it can be roughly regarded as a constant. However, if you want to accurately obtain the above-mentioned many related information, you can still charge by sampling more battery packs. When the state is at the reference point of Ef or Eb, the number of equations of the simultaneous equation is increased, that is, the more complex factor (Pe) can be solved in step 75.

In this way, according to the calculation method of the battery group related information disclosed in the present invention, the known charging efficiency, the discharging efficiency and the power loss rate are used to measure the energy and the state change of the battery during the charging and discharging process, and the battery pack is accurately estimated. Remaining power; not only simple structure, limited resources, but also can detect the impact of driving conditions on power consumption, increase the accuracy of detecting power, and facilitate the driver to clearly confirm that the voyage can continue.

However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications according to the scope of the present invention and the description of the invention are all It is still within the scope of the invention patent.

10, 10’‧‧‧ electric vehicles

20‧‧‧Preferred electric vehicle electricity quantity estimation system

40‧‧‧Charging device

31‧‧‧Battery Pack

32‧‧‧Power consumption devices

33‧‧‧Detection processing device

34‧‧‧Car condition detection device

35‧‧‧Display device

331‧‧‧ Controller

332‧‧‧Voltage/Current Detector

335‧‧‧clock signal control module

61~66, 71~75‧‧‧ Process steps

1 is a schematic diagram of a system interface of a conventional electric vehicle electric quantity estimating system; FIG. 2 is a schematic diagram of a system operation of a conventional electric vehicle electric quantity estimating system; FIG. 3 is a perspective view showing the appearance of the electric vehicle according to the first embodiment of the present invention; FIG. 5 is a block diagram showing a method for calculating battery level related information of an electric vehicle according to a first embodiment of the present invention; FIG. 5 is a flowchart of a method for calculating battery level related information according to a first embodiment of the present invention; FIG. 7 is a partial block diagram of an electric vehicle according to a first embodiment of the present invention; FIG. 8 is a partial block diagram of an electric vehicle according to a first embodiment of the present invention; FIG. Stand-by view, a schematic view of the display device; Fig. 9 is a top plan view showing the display device during running of the electric vehicle according to the first embodiment of the present invention.

10 is a state diagram of a state of charge of a battery pack according to a second embodiment of the present invention; FIG. 11 is a diagram of a battery state related information calculation method according to a second embodiment of the present invention; The second state of the electric quantity state diagram; and FIG. 12 is a flow chart of the battery unit related information calculation method according to the second embodiment of the present invention.

61~66‧‧‧ Process steps

Claims (10)

An instant calculation method for battery pack information of an electric vehicle, wherein the battery pack has a predetermined saturation state Ef, and the battery pack is electrically connected to a group of charging devices and a group of power consuming devices respectively, and the charging device inputs the electric energy of the battery pack And the power outputted by the battery pack to the power consuming device can be measured by a group of detecting processing devices, the method comprising the following steps: a) when the battery pack reaches the predetermined saturation state, recording the time point as a The time calculation reference point t _f1 ; b) the detection processing device measures the input and output power of the battery pack from the time calculation reference point t _f1 ; c) detects whether the battery pack reaches the predetermined saturation state again Ef, if it is reached, calculating a time interval Tet from which the reference point t _{f1 is} calculated to the time when the predetermined saturation state Ef is reached again, and the reference point t _f2 is calculated; and d) the total input and output according to the time interval The electric energy, and the length of the time interval, calculating a power loss rate Pe that is not output to the power consuming device during the time interval; wherein the power loss rate Where ε _C is the charging efficiency, ε _D is the discharge efficiency, and Ect is the total charging energy during the time interval , Eut is the total power consumption in this time interval . The calculation method described in claim 1 further includes the step e) of calculating the remaining power of the battery pack according to the power loss rate Pe after the step d); . The calculation method described in claim 1 further includes the step f) of calculating the charging efficiency ε _C according to the power loss rate Pe; wherein the charging efficiency The calculation method described in claim 1 further includes the step g) of calculating the charging efficiency ε _D according to the power loss rate Pe; wherein the discharge efficiency An instant calculation method for battery pack information for electric vehicles, wherein the battery pack has a predetermined saturation state Ef and a predetermined low limit state Eb, and the battery packs are electrically connected to a group of charging devices and a group of power consuming devices respectively, the charging The power input to the battery pack and the power output by the battery pack to the power consuming device can be measured by a group of detecting processing devices, and the method includes the following steps: h) reaching the predetermined saturation state in the battery pack Or when the low limit state is predetermined, the time point is recorded as a time calculation reference point t _start ; i) the detection processing device measures the input/output power of the battery pack from the time calculation reference point, and each of the inputs /output time interval; j) detecting whether the battery pack reaches the predetermined saturation/lower limit state again, and whether the predetermined low limit/saturation state is reached, measuring and recording the time calculation reference of the first two of the above two Point t _middle and the time of the later occurrence to calculate a reference point t _end ; wherein at least one of the battery state of the reference point for calculating the reference point is at the predetermined saturation State and one of the predetermined low limit states; and k) calculating the charging efficiency ε _C and/or the discharging efficiency ε _{D in} accordance with the total input and output electrical energy during the time interval and the length of the time intervals ;l) Calculate the power loss rate . The calculation method according to claim 5, wherein in the step k), the charging efficiency ε _C and the discharge efficiency ε _D are respectively: Wherein, either of tstart', tmiddle', and tend' are substituted into the formula as tf1 and tf2, respectively. The calculation method as described in claim 5, further comprising the following steps after the above steps: m) calculating the residual charge ER of the battery by the above charging efficiency ε _C and/or the discharge efficiency ε _D ; and n) The battery pack residual power is divided by the output power and the current speed is used to obtain the endurance travel SR and/or the endurance time; wherein the step n) further comprises the following steps: n1) obtaining the battery pack output electric power Pi and the electric vehicle travel speed V; n2) The remaining battery power is divided by the battery output power and multiplied by the electric vehicle traveling speed to obtain the endurance travel, that is, SR=ER/Pi‧V. An electric vehicle is electrically connected to a set of charging devices and receives electrical energy input by the charging device, the electric vehicle comprising: a set of vehicle condition detecting devices for measuring the driving speed and/or distance of the electric vehicle; a battery pack that should consume electric energy and can receive input power of the charging device and has a predetermined saturation state Ef; a group records the time when the battery pack reaches the predetermined saturation state as a time calculation reference point; from the reference point Measure the charging device to input the battery pack and the electric energy output by the battery pack; detect the re-saturation time when the battery pack reaches the predetermined saturation state again, and the time interval between the re-saturation time and the reference point; The total input/output power during the time interval and the length of the time interval, calculating a power loss rate that is not supplied to the electric vehicle during the time interval; calculating a remaining power of the battery group according to the power loss rate; and according to the battery pack The remaining power and the output information of the vehicle condition detecting device are used to estimate the detection of the endurance of the electric vehicle a processing device; and a set of display devices displaying the endurance stroke estimated by the detection processing device; wherein the power loss rate , the remaining battery , the endurance stroke SR = ER / Pi‧ V. The electric vehicle of claim 8, wherein the detection processing device comprises: a set of current/voltage detectors electrically connected to the battery pack; and a set of electrical connections to the current/voltage detector and the Control of the vehicle condition detection device Controller. The electric vehicle according to claim 9, wherein the controller further comprises a clock signal control module for providing a clock signal for the controller to obtain reference time data.