Electric vehicle battery constant temperature control system and electric vehicle

Abstract

The utility model discloses an electric vehicle battery constant temperature control system and an electric vehicle, the electric vehicle battery constant temperature control system comprises a charging loop and a temperature control loop, the charging loop comprises a battery pack, a charging port and a charger plug, the first positive electrode end and the first negative electrode end of the charger plug are connected with the second positive electrode end and the second negative electrode end of the battery pack through the charging port respectively, the temperature control loop comprises a heating device, a temperature control switch and a converter, and the converter is provided with a third positive electrode end, a third negative electrode end and a 12V output end. The third positive electrode end, the heating device, the temperature control switch and the 12V output end are sequentially connected to form a loop, the third negative electrode end is connected with the first negative electrode end, and the heating device is arranged around the battery pack; when the temperature of the battery pack is lower than the rated temperature of the temperature control switch, the temperature control switch is closed, and the heating device operates, and when the temperature of the battery pack is higher than the rated temperature of the temperature control switch, the temperature control switch is disconnected, and the heating device is closed.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery, especially to a kind of electric vehicle battery constant temperature control system and electric vehicle. BACKGROUND

[0002] In electric two-wheeled vehicle or electric three-wheeled vehicle, lead-acid battery or lithium battery is equipped as power source, but the charging capacity of such battery is less in low temperature environment due to its material characteristics and other reasons, which directly affects the vehicle endurance.

[0003] The negative effects of charging in low temperature environment include: 1, charging efficiency decline and virtual electricity phenomenon: when the temperature is lower than 0℃, the reaction rate of active substance in the battery is reduced, the charging time is prolonged and the "not full" phenomenon (such as charging indicator light turns green, actual power is insufficient) is easy to appear. Lead-acid battery is more affected by low temperature, and the capacity decreases by about 0.8% for every 1℃ decrease in temperature. The viscosity of electrolyte increases at low temperature, which increases the resistance of chemical reaction and significantly reduces the charging efficiency. For example, the charging efficiency of lithium battery at 0℃ may be only 44% of that at normal temperature. 2, battery capacity and endurance decay: low temperature will directly reduce the available capacity of battery, when the temperature drops to 0℃, the battery capacity may be only 70% of that at normal temperature, and the endurance mileage is reduced by more than 30%. 3, safety hazard: lithium dendrite risk, when charging at low temperature (especially below 0℃), lithium ions cannot be normally inserted into the negative electrode, which may form lithium dendrite to pierce the diaphragm, causing internal short circuit and thermal runaway. 4, battery bulging and leakage: long-term low-temperature charging will cause electrolyte evaporation and abnormal internal pressure, increasing the risk of shell deformation. 5, shortening of service life: repeated low-temperature charging will accelerate the expansion of electrode material cracks and the decomposition of electrolyte, resulting in 20%-30% reduction of battery life.

[0004] In the prior art, the measures to cope with low temperature charging include: optimizing charging environment, and charging in indoor or underground garage with temperature higher than 5℃, to avoid open-air environment. Avoid extreme low temperature period: charge at noon or during the day when the temperature is higher. However, these methods have great limitations, and the time and place of charging are greatly limited, which cannot ensure that the battery maintains in a suitable temperature range under charging state. UTILITY MODEL CONTENTS

[0005] The utility model aims at the defects of prior art, and provides a kind of electric vehicle battery constant temperature control system and electric vehicle.

[0006] To solve the above technical problems, the utility model provides the technical scheme as follows:

[0007] In a first aspect, a battery constant temperature control system for an electric vehicle is provided, which comprises a charging circuit and a temperature control circuit, the charging circuit comprises a battery pack, a charging port and a charger plug, the first positive terminal and the first negative terminal of the charger plug are connected to the second positive terminal and the second negative terminal of the battery pack through the charging port respectively, the temperature control circuit comprises a heating device, a temperature control switch and a converter, the third positive terminal, the heating device, the temperature control switch and the 12V output terminal are connected in sequence to form a loop, the third negative terminal is connected to the first negative terminal, and the heating device is arranged around the battery pack; when the temperature of the battery pack is lower than the rated temperature of the temperature control switch, the temperature control switch is closed and the heating device is turned on, and when the temperature of the battery pack is higher than the rated temperature of the temperature control switch, the temperature control switch is turned off and the heating device is turned off.

[0008] Further, at least one signal terminal is arranged on the converter, the signal terminal is connected to a control terminal in the charger plug, and the control terminal is connected to the first positive terminal.

[0009] Further, the signal terminal and the control terminal are connected in the charging port.

[0010] Further, the temperature control switch is a normally closed switch and has a hysteresis characteristic.

[0011] Further, the rated temperature is 25 DEG C.

[0012] Further, the heating device is a heating wire.

[0013] Further, the heating wire is arranged at the bottom of the battery pack.

[0014] Further, the power supply voltage of the heating device is 12V.

[0015] In a second aspect, an electric vehicle is provided, which comprises the battery constant temperature control system for an electric vehicle.

[0016] Further, the electric vehicle comprises a two-wheeled electric vehicle and a three-wheeled electric vehicle.

[0017] Compared with the prior art, the electric vehicle has the advantages that:

[0018] When the temperature in the battery compartment is low, the converter supplies power to the heating wire through the temperature control switch; when the temperature rises above the rated temperature of the temperature control switch, the temperature control switch is turned off to prevent the battery from overheating; when the temperature decreases to the closing temperature of the temperature control switch, the temperature control switch is closed to heat again. The battery in the charging state is maintained in a suitable temperature range, the activity of the battery material is improved, the battery can be charged more fully in a low temperature environment, and the low temperature endurance of the electric vehicle is improved. Low cost, simple structure, strong compatibility, suitable for various two-wheeled and three-wheeled electric vehicles. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structure schematic view of the embodiment one of the present application.

[0020] In the figure: 1-battery pack, 2-charging port, 3-charger plug, 4-heating wire, 5-temperature control switch, 6-converter, 11-second positive terminal, 12-second negative terminal, 31-first positive terminal, 32-first negative terminal, 33-control terminal, 61-third positive terminal, 62-third negative terminal, 63-12V output terminal, 64-signal terminal. DETAILED DESCRIPTION

[0021] In order to deepen the understanding of the present application, we will further describe the present application in combination with the drawings, and the embodiment is only used to explain the present application, and does not constitute a limitation on the protection scope of the present application.

[0022] In the present application, unless otherwise specified and limited, the terms "mounting", "connecting", "connecting", "fixing", "setting" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication or interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0023] Embodiment one

[0024] As Figure 1As shown, a battery constant temperature control system of an electric vehicle includes a charging circuit and a temperature control circuit. The charging circuit includes a battery pack 1, a charging port 2, and a charger plug 3. A first positive terminal 31 and a first negative terminal 32 of the charger plug 3 are connected to a second positive terminal 11 and a second negative terminal 12 of the battery pack 1 through the charging port 2 respectively. The temperature control circuit includes a heating device, a temperature control switch 5, and a converter 6. The converter 6 is provided with a third positive terminal 61, a third negative terminal 62, and a 12V output terminal 63. The third positive terminal 61, the heating device, the temperature control switch 5, and the 12V output terminal 63 are connected in sequence to form a loop. The third negative terminal 62 is connected to the first negative terminal 32. The heating device is arranged around the battery pack 1. When the temperature of the battery pack 1 is lower than a rated temperature of the temperature control switch 5, the temperature control switch 5 is closed, and the heating device is operated. When the temperature of the battery pack 1 is higher than the rated temperature of the temperature control switch 5, the temperature control switch 5 is opened, and the heating device is turned off.

[0025] Preferably, the converter 6 is provided with a signal terminal 64. The signal terminal 64 is connected to a control terminal 33 in the charger plug 3 in the charging port 2. The control terminal 33 is connected to the first positive terminal 31.

[0026] Preferably, the temperature control switch 5 is a normally closed switch and has a hysteresis characteristic. The rated temperature is set to 25℃.

[0027] Preferably, the heating device adopts a heating wire 4. The heating wire 4 is arranged at the bottom of the battery pack 1. The power supply voltage of the heating wire 4 is 12V.

[0028] When the charger plug 3 is inserted into the charging port 2, the third positive terminal 61 of the converter 6 is short-circuited with the signal terminal 64 through the control terminal 33 of the charger plug 3. The converter 6 is started to work to convert the high voltage from the charger plug 3 into 12V voltage output. When the temperature of the battery pack 1 in the battery compartment is low, the converter 6 supplies power to the heating wire 4 through the temperature control switch 5. When the temperature rises above the rated temperature of the temperature control switch 5, the temperature control switch 5 is opened to prevent the battery pack 1 from thermal runaway when the temperature is too high. When the temperature decreases to the rated temperature of the temperature control switch 5, the temperature control switch 5 is closed to heat again. The above process is repeated to maintain the battery pack 1 in a charging state in an appropriate temperature range, improve the activity of the battery material, and enable the battery pack 1 to be fully charged in a low-temperature environment, thereby improving the low-temperature endurance of the electric vehicle.

[0029] Embodiment two

[0030] An electric vehicle includes the battery constant temperature control system of the electric vehicle in the embodiment one. The electric vehicle can be an electric two-wheeled vehicle or an electric three-wheeled vehicle. After the electric vehicle adopts the above battery constant temperature control system, the electric vehicle also has the above advantages and effects, which will not be described herein.

[0031] The above embodiment is only for illustrating the technical concept and structural features of the present application, and is intended to enable those skilled in the art to implement the present application, but the above content does not limit the protection scope of the present application, and any equivalent changes or modifications made according to the spirit and principle of the present application shall fall within the protection scope of the present application.

Claims

1. A constant temperature control system for an electric vehicle battery, characterized in that: The device includes a charging circuit and a temperature control circuit. The charging circuit includes a battery pack (1), a charging port (2), and a charger plug (3). The first positive terminal (31) and the first negative terminal (32) of the charger plug (3) are connected to the second positive terminal (11) and the second negative terminal (12) of the battery pack (1) through the charging port (2), respectively. The temperature control circuit includes a heating device, a temperature control switch (5), and a converter (6). The converter (6) is provided with a third positive terminal (61), a third negative terminal (62), and a 12V output terminal. (63) The third positive terminal (61), heating device, temperature control switch (5), and 12V output terminal (63) are connected in sequence to form a circuit. The third negative terminal (62) is connected to the first negative terminal (32). The heating device is set around the battery pack (1). When the temperature of the battery pack (1) is lower than the rated temperature of the temperature control switch (5), the temperature control switch (5) is closed and the heating device is running. When the temperature of the battery pack (1) is higher than the rated temperature of the temperature control switch (5), the temperature control switch (5) is opened and the heating device is turned off.

2. The electric vehicle battery constant temperature control system according to claim 1, characterized in that: The converter (6) is provided with at least one signal terminal (64), which is connected to the control terminal (33) in the charger plug (3), and the control terminal (33) is connected to the first positive terminal (31).

3. The electric vehicle battery constant temperature control system according to claim 2, characterized in that: The signal terminal (64) and the control terminal (33) are connected in the charging port (2).

4. The electric vehicle battery constant temperature control system according to claim 1, characterized in that: The temperature control switch (5) is a normally closed switch and has hysteresis characteristics.

5. The electric vehicle battery constant temperature control system according to claim 1, characterized in that: The rated temperature is 25°C.

6. The electric vehicle battery constant temperature control system according to claim 1, characterized in that: The heating device includes a heating wire (4).

7. The electric vehicle battery constant temperature control system according to claim 6, characterized in that: The heating wire (4) is located at the bottom of the battery pack (1).

8. The electric vehicle battery constant temperature control system according to claim 1, characterized in that: The heating device is powered by 12V.

9. An electric vehicle, characterized in that: The electric vehicle battery constant temperature control system includes any one of claims 1-8.

10. An electric vehicle according to claim 9, characterized in that: The electric vehicles include two-wheeled electric vehicles and three-wheeled electric vehicles.

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