Testing device for simulating dark current over-discharge of battery on whole vehicle
By designing a switching branch circuit that automatically adjusts the battery's internal resistance to simulate the vehicle's dark current over-discharge, the problem of battery failure during long-term storage in existing technologies has been solved, and stable discharge testing without human intervention has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUBEI HONGBEN ENERGY CO LTD
- Filing Date
- 2025-04-27
- Publication Date
- 2026-04-28
AI Technical Summary
Existing technologies cannot effectively simulate the dark current over-discharge process of a vehicle, leading to battery failure during long-term storage. Furthermore, the method of manually adjusting internal resistance is costly and prone to errors.
Design a test device to simulate the dark current over-discharge of a battery in a vehicle. The device automatically adjusts the battery's internal resistance through parallel switch branch circuits to ensure that the discharge current is maintained between 20 and 30 mA. The device includes first to fifth switch branch circuits and uses Ohm's law to calculate the set voltage and current of each resistor and voltage control switch.
It enables automatic adjustment of voltage without the need for manual real-time monitoring, ensuring stable discharge current, reducing operating costs, and improving the accuracy and convenience of testing.
Smart Images
Figure CN224176710U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of vehicle battery technology, specifically relating to a test device for simulating the dark current over-discharge of a battery in a vehicle, which is used to simulate the process of long-term dark current discharge of a battery in a vehicle. Background Technology
[0002] Due to the booming development of new energy vehicles in China, the market for gasoline-powered vehicles has been impacted, leading to difficulties in selling vehicles promptly after production and resulting in long inventory cycles. Since the dark current of a vehicle is typically 20-30mA, at least 15Ah of battery power is consumed for every month a vehicle is stored. Given that the typical battery capacity is around 60-80Ah, after 4-6 months of storage, the battery will be completely depleted, leading to irreversible sulfation and battery failure.
[0003] Since the dark current of a vehicle is only in the mA range, conventional battery testing equipment cannot be set to such a low current value. Therefore, battery testing units often use a single resistor to simulate dark current discharge. However, during dark current discharge, the battery voltage continuously decreases. Using only a constant resistor will inevitably lead to a progressively lower discharge current, eventually falling below the expected 20-30 mA. To ensure the discharge current remains between 20-30 mA, it is necessary to measure the battery voltage in real time and replace the connection resistor promptly. This operation incurs significant labor and internal resistance costs, and the frequent manual replacement of the internal resistance is prone to errors, leading to deviations from expectations and inaccurate test results. Utility Model Content
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a test device for simulating the dark current over-discharge of a battery in a vehicle. During the test, this device will automatically adjust the internal resistance of the battery according to the actual battery voltage, so that the actual discharge current of the battery is always kept between 20~30mA. No manual operation is required, the battery voltage does not need to be monitored in real time during the test, it is easy to install, can be reused, and is inexpensive.
[0005] The technical solution of this utility model is: a test device for simulating the dark current over-discharge of a battery in a vehicle, characterized in that: it includes first to fifth switch branches connected in parallel between the positive terminal P and the negative terminal N; wherein, the first switch branch is composed of a first constant resistor R1; the second switch branch is composed of a second constant resistor R2 and a second voltage control switch S2 connected in series; the third switch branch is composed of a third constant resistor R3 and a third voltage control switch S3 connected in series; the fourth switch branch is composed of a fourth constant resistor R4 and a fourth voltage control switch S4 connected in series; and the fifth switch branch is composed of a fifth constant resistor R5 and a fifth voltage control switch S5 connected in series.
[0006] In the technical solution of this utility model, the second voltage control switch S2, the third voltage control switch S3, the fourth voltage control switch S4, and the fifth voltage control switch S5 are all closed and energized when the voltage is lower than their set voltage.
[0007] In the technical solution of this utility model, the resistance value of the first constant resistor R1 is calculated according to Ohm's law R1=U1 / I1, where the voltage U1 is the highest voltage Umax when the battery is fully charged, and the current I1 is the upper limit of dark current 30mA.
[0008] In the technical solution of this utility model, the second set voltage U22 of the second voltage control switch S2 is calculated according to Ohm's law U22=I22*R22, where the current I22 is the lower limit of dark current 20mA, and the resistance R22 is the resistance value of the first constant resistor R1; the resistance value of the second constant resistor R2 is calculated according to the formula R2=1 / (I2 / U2-1 / R22), where the voltage U2 is the second set voltage U22 of the second voltage control switch S2, and the current I2 is the upper limit of dark current 30mA.
[0009] In the technical solution of this utility model, the third set voltage U33 of the third voltage control switch S3 is calculated according to Ohm's law U33=I33*R33, where the current I33 is the lower limit of dark current 20mA, and the resistance R33 is 1 / (1 / R1+1 / R2); the resistance value of the third constant resistor R3 is calculated according to the formula R3=1 / (I3 / U3-1 / R33), where the voltage U3 is the third set voltage U33 of the third voltage control switch S3, and the current I3 is the upper limit of dark current 30mA.
[0010] In the technical solution of this utility model, the fourth set voltage U44 of the fourth voltage control switch S4 is calculated according to Ohm's law U44=I44*R44, where the current I44 is the lower limit of dark current 20mA, and the resistance R44 is 1 / (1 / R1+1 / R2+1 / R3); the resistance value of the fourth constant resistor R4 is calculated according to the formula R4=1 / (I4 / U4-1 / R44), where the voltage U4 is the fourth set voltage U44 of the fourth voltage control switch S4, and the current I4 is the upper limit of dark current 30mA.
[0011] In the technical solution of this utility model, the fifth set voltage U55 of the fifth voltage control switch S5 is calculated according to Ohm's law U55=I55*R55, where the current I55 is the lower limit of dark current 20mA, and the resistance R55 is 1 / (1 / R1+1 / R2+1 / R3+1 / R4); the resistance value of the fifth constant resistor R5 is calculated according to the formula R5=1 / (I5 / U5-1 / R55), where the voltage U5 is the fifth set voltage U55 of the fifth voltage control switch S5, and the current I5 is the upper limit of dark current 30mA.
[0012] In the technical solution of this utility model, the highest voltage Umax of the battery in a fully charged state is 13.5V, the second set voltage U22 is 9V, the third set voltage U33 is 6V, the fourth set voltage U44 is 4V, and the fifth set voltage U55 is 2.67V.
[0013] In the technical solution of this utility model, the internal resistance of the first constant resistor R1 is 450Ω, the value of the second constant resistor R2 is 900Ω, the value of the third constant resistor R3 is 600Ω, the value of the fourth constant resistor R4 is 400Ω, and the value of the fifth constant resistor R5 is 270Ω.
[0014] This invention is simple to operate and easy to install and remove. No additional operation is required on the test battery or test device during the test. During the test, the internal resistance of the circuit is automatically changed as the battery voltage drops, thereby ensuring that the dark current of the discharge is always kept between 20~30mA, effectively simulating the dark current discharge of the battery in the whole vehicle.
[0015] This invention is mainly used for testing the dark current over-discharge of a battery in a vehicle. Attached Figure Description
[0016] Figure 1 This is a circuit diagram of the present invention.
[0017] Appendix: P - Positive terminal; N - Negative terminal; R1 - First constant resistor; R2 - Second constant resistor; R3 - Third constant resistor; R4 - Fourth constant resistor; R5 - Fifth constant resistor; S2 - Second voltage control switch; S3 - Third voltage control switch; S4 - Fourth voltage control switch; S5 - Fifth voltage control switch. Detailed Implementation
[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0019] It should be noted that similar reference numerals and letters in the accompanying drawings indicate similar items. In the description of this utility model, it should be understood that the terms "upper," "lower," "top," "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0020] like Figure 1 As shown, one embodiment of the test device for simulating dark current over-discharge of a battery in a vehicle according to this utility model includes first to fifth switch branches connected in parallel between the positive terminal P and the negative terminal N. The first switch branch is composed of a first constant resistor R1; the second switch branch is composed of a second constant resistor R2 and a second voltage control switch S2 connected in series; the third switch branch is composed of a third constant resistor R3 and a third voltage control switch S3 connected in series; the fourth switch branch is composed of a fourth constant resistor R4 and a fourth voltage control switch S4 connected in series; and the fifth switch branch is composed of a fifth constant resistor R5 and a fifth voltage control switch S5 connected in series. The second voltage control switch S2, the third voltage control switch S3, the fourth voltage control switch S4, and the fifth voltage control switch S5 are all voltage control switches that are energized when the voltage is lower than their set voltage.
[0021] In the first switching branch circuit, the resistance value of the first constant resistor R1 is calculated according to Ohm's law R1=U1 / I1, where the voltage U1 is taken as the highest voltage Umax=13.5V of the lead-acid battery under full charge, and the current I1 is taken as the upper limit of dark current 30mA. The internal resistance value of the first constant resistor R1 is 450Ω.
[0022] In the second switch branch circuit, the second set voltage U22 of the second voltage control switch S2 is calculated according to Ohm's law U22=I22*R22, where the current I22 is taken as the lower limit of dark current 20mA, and the resistance R22 is taken as the resistance value of the first constant resistor R1; the resistance value of the second constant resistor R2 is calculated according to the formula R2=1 / (I2 / U2-1 / R22), where the voltage U2 is taken as the second set voltage U22 of the second voltage control switch S2, and the current I2 is taken as the upper limit of dark current 30mA. The second set voltage U22 is 9V, and the value of the second constant resistor R2 is 900Ω.
[0023] In the third switch branch circuit, the third set voltage U33 of the third voltage control switch S3 is calculated according to Ohm's law U33=I33*R33, where the current I33 is taken as the lower limit of dark current 20mA, and the resistance R33 is taken as 1 / (1 / R1+1 / R2) =300Ω; the resistance value of the third constant resistor R3 is calculated according to the formula R3=1 / (I3 / U3-1 / R33), where the voltage U3 is taken as the third set voltage U33 of the third voltage control switch S3, and the current I3 is taken as the upper limit of dark current 30mA. The third set voltage U33 is 6V, and the value of the third constant resistor R3 is 600Ω.
[0024] In the fourth switch branch circuit, the fourth set voltage U44 of the fourth voltage control switch S4 is calculated according to Ohm's law U44=I44*R44, where the current I44 is taken as the lower limit of dark current 20mA, and the resistance R44 is 1 / (1 / R1+1 / R2+1 / R3)=200Ω; the resistance value of the fourth constant resistor R4 is calculated according to the formula R4=1 / (I4 / U4-1 / R44), where the voltage U4 is taken as the fourth set voltage U44 of the fourth voltage control switch S4, and the current I4 is taken as the upper limit of dark current 30mA. The fourth set voltage U44 is 4V, and the value of the fourth constant resistor R4 is 400Ω.
[0025] In the fifth switch branch circuit, the fifth set voltage U55 of the fifth voltage control switch S5 is calculated according to Ohm's law U55=I55*R55, where the current I55 is taken as the lower limit of dark current 20mA, and the resistance R55 is taken as 1 / (1 / R1+1 / R2+1 / R3+1 / R4)=133.33Ω; the resistance value of the fifth constant resistor R5 is calculated according to the formula R5=1 / (I5 / U5-1 / R55), where the voltage U5 is taken as the fifth set voltage U55 of the fifth voltage control switch S5, and the current I5 is taken as the upper limit of dark current 30mA. The fifth set voltage U55 can be taken as 2.67V, and the value of the fifth constant resistor R5 can be taken as 270Ω.
[0026] During testing, the positive terminal P and negative terminal N of the test device for simulating dark current over-discharge of a battery in a vehicle are directly connected to the positive and negative terminals of the battery under test, respectively.
[0027] Generally, the upper limit of the open-circuit voltage of a lead-acid battery after full charge is 13.5V, while the voltage of a fully discharged battery is about 2V. If the battery voltage is between 13.5V and 9V, the second voltage control switch S2, the third voltage control switch S3, the fourth voltage control switch S4, and the fifth voltage control switch S5 are all in the open state. At this time, only the first switch branch circuit in the test circuit is energized, that is, the resistance value of the circuit is equal to the resistance value of the first constant resistor R1, which is 450Ω. According to Ohm's law I=U / R, the discharge current range of the battery at this time is 30mA~20mA.
[0028] When the battery voltage is between 9V and 6V, the second voltage control switch S2 is closed, and the third voltage control switch S3, the fourth voltage control switch S4, and the fifth voltage control switch S5 are all open. At this time, the test circuit is a parallel circuit of the first switch branch circuit and the second switch branch circuit. That is, the resistance value of the circuit is equal to the parallel resistance value of the first constant resistor R1 and the second constant resistor R2, R33 = 300Ω. According to Ohm's law I = U / R, the battery discharge current range of the test circuit at this time is 30mA to 20mA.
[0029] When the battery voltage is between 6V and 4V, the second voltage control switch S2 and the third voltage control switch S3 are closed, while the fourth voltage control switch S4 and the fifth voltage control switch S5 are open. At this time, the test circuit is a parallel circuit of the first switch branch circuit, the second switch branch circuit, and the third switch branch circuit. That is, the resistance value of the circuit is equal to the parallel resistance value of the first constant resistor R1, the second constant resistor R2, and the third constant resistor R3, R44 = 200Ω. According to Ohm's law I = U / R, the battery discharge current range of the test circuit at this time is 30mA to 20mA.
[0030] When the battery voltage is between 4V and 2.67V, the second voltage control switch S2, the third voltage control switch S3, and the fourth voltage control switch S4 are closed, and the fifth voltage control switch S5 is open. At this time, the test circuit is a parallel circuit of the first switch branch circuit, the second switch branch circuit, the third switch branch circuit, and the fourth switch branch circuit. That is, the resistance value of the circuit is equal to the parallel resistance value of the first constant resistor R1, the second constant resistor R2, the third constant resistor R3, and the fourth constant resistor R4, R55 = 133.33Ω. According to Ohm's law I = U / R, the battery discharge current range of the test circuit at this time is 30mA to 20.025mA.
[0031] When the battery voltage is between 2.67V and 1.79V, the second voltage control switch S2 and the third voltage control switch S3 are closed, and the fourth voltage control switch S4 and the fifth voltage control switch S5 are all closed. At this time, the test circuit is a parallel circuit of the first switch branch circuit, the second switch branch circuit, the third switch branch circuit, the fourth switch branch circuit, and the fifth switch branch circuit. That is, the resistance value of the circuit is equal to the parallel resistance value of the first constant resistor R1, the second constant resistor R2, the third constant resistor R3, the fourth constant resistor R4, and the fifth constant resistor R5, which is 1 / (1 / R1+1 / R2+1 / R3+1 / R4+1 / R5)=89.256Ω. According to Ohm's law I=U / R, the battery discharge current range of the test circuit at this time is 29.914mA~20.055mA.
[0032] If the battery voltage is below 2V, it is generally considered that the battery is in a completely depleted state and can no longer output electrical energy.
[0033] This invention features simple operation, convenient installation and removal, and no additional operation required for the test battery or test device during the testing process. During the test, the internal resistance of the circuit is automatically changed as the battery voltage decreases, thereby ensuring that the dark current of the discharge is always kept between 20 and 30mA, effectively simulating the dark current discharge of the battery in the whole vehicle.
[0034] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A test device for simulating dark current over-discharge of a battery in a vehicle, characterized in that: It includes first to fifth switch branches connected in parallel between the positive terminal P and the negative terminal N; wherein, the first switch branch is composed of a first constant resistor R1; the second switch branch is composed of a second constant resistor R2 and a second voltage control switch S2 connected in series; the third switch branch is composed of a third constant resistor R3 and a third voltage control switch S3 connected in series; the fourth switch branch is composed of a fourth constant resistor R4 and a fourth voltage control switch S4 connected in series; and the fifth switch branch is composed of a fifth constant resistor R5 and a fifth voltage control switch S5 connected in series.
2. The test device for simulating dark current over-discharge of a battery in a vehicle according to claim 1, characterized in that: The second voltage control switch S2, the third voltage control switch S3, the fourth voltage control switch S4, and the fifth voltage control switch S5 are all energized when the voltage is lower than their set voltage.
3. The test device for simulating dark current over-discharge of a battery in a vehicle according to claim 2, characterized in that: The resistance value of the first constant resistor R1 is calculated according to Ohm's law R1=U1 / I1, where the voltage U1 is the highest voltage Umax when the battery is fully charged, and the current I1 is the upper limit of dark current 30mA.
4. The test device for simulating dark current over-discharge of a battery in a vehicle according to claim 3, characterized in that: The second set voltage U22 of the second voltage control switch S2 is calculated according to Ohm's law U22=I22*R22, where the current I22 is the lower limit of dark current 20mA, and the resistance R22 is the resistance value of the first constant resistor R1; the resistance value of the second constant resistor R2 is calculated according to the formula R2=1 / (I2 / U2-1 / R22), where the voltage U2 is the second set voltage U22 of the second voltage control switch S2, and the current I2 is the upper limit of dark current 30mA.
5. The test device for simulating dark current over-discharge of a battery in a vehicle according to claim 4, characterized in that: The third set voltage U33 of the third voltage control switch S3 is calculated according to Ohm's law U33=I33*R33, where the current I33 is the lower limit of dark current 20mA, and the resistance R33 is 1 / (1 / R1+1 / R2); the resistance value of the third constant resistor R3 is calculated according to the formula R3=1 / (I3 / U3-1 / R33), where the voltage U3 is the third set voltage U33 of the third voltage control switch S3, and the current I3 is the upper limit of dark current 30mA.
6. The test device for simulating dark current over-discharge of a battery in a vehicle according to claim 5, characterized in that: The fourth set voltage U44 of the fourth voltage control switch S4 is calculated according to Ohm's law U44=I44*R44, where the current I44 is the lower limit of dark current 20mA, and the resistance R44 is 1 / (1 / R1+1 / R2+1 / R3); the resistance value of the fourth constant resistor R4 is calculated according to the formula R4=1 / (I4 / U4-1 / R44), where the voltage U4 is the fourth set voltage U44 of the fourth voltage control switch S4, and the current I4 is the upper limit of dark current 30mA.
7. The test device for simulating dark current over-discharge of a battery in a vehicle according to claim 6, characterized in that: The fifth set voltage U55 of the fifth voltage control switch S5 is calculated according to Ohm's law U55=I55*R55, where the current I55 is the lower limit of dark current 20mA, and the resistance R55 is 1 / (1 / R1+1 / R2+1 / R3+1 / R4); the resistance value of the fifth constant resistor R5 is calculated according to the formula R5=1 / (I5 / U5-1 / R55), where the voltage U5 is the fifth set voltage U55 of the fifth voltage control switch S5, and the current I5 is the upper limit of dark current 30mA.
8. The test device for simulating dark current over-discharge of a battery in a vehicle according to claim 7, characterized in that: The maximum voltage Umax of the battery when fully charged is 13.5V, the second set voltage U22 is 9V, the third set voltage U33 is 6V, the fourth set voltage U44 is 4V, and the fifth set voltage U55 is 2.67V.
9. The test device for simulating dark current over-discharge of a battery in a vehicle according to claim 8, characterized in that: The first constant resistor R1 has an internal resistance of 450Ω, the second constant resistor R2 has a value of 900Ω, the third constant resistor R3 has a value of 600Ω, the fourth constant resistor R4 has a value of 400Ω, and the fifth constant resistor R5 has a value of 270Ω.