Charger for a vehicle and control method thereof

Abstract

A vehicle-mounted charger for charging a battery of a portable device, comprising: a memory (10) which stores a charge table in which ratios of the charge quantity of the battery of the portable device to voltage bandwidths of the vehicle battery are written; a voltage monitor (20) that monitors the voltage of the vehicle battery at a predetermined time interval; a plug-in device (30) of the portable device that receives the portable device and charges the battery of the portable device by the voltage of the vehicle battery; and a charging controller (50) that detects the portable device being received through the plug (30) of the portable device and controls the plug (30) of the portable device so that the battery of the portable device is charged by the voltage of the vehicle battery to a voltage value that corresponds to the monitored voltage of the vehicle battery in the charging table, where the charging control (50) is set up, to fully charge the battery of the portable device in a first voltage bandwidth, to partially charge the battery of the portable device in a second voltage bandwidth, and not to charge the battery of the portable device in a third voltage bandwidth.

Description

BACKGROUND Area of ​​the invention

[0001] The present application relates to a charger for a vehicle. In particular, the present application relates to a charger installed in a vehicle, designed to periodically monitor the voltage of a vehicle battery and, when a portable device required for charging is detected, to control the charge level of a battery in the portable device based on the monitored voltage of the vehicle battery, as well as a control method thereof. Description of the state of the art

[0002] A battery used in a vehicle must maintain a sufficient state of charge to improve stability, lifespan, and output power. Therefore, it is necessary to regularly check and manage the vehicle battery's condition, such as its state of charge (SOC) and state of health (SOH). Many in-vehicle chargers have been developed for this purpose.

[0003] Conventional in-vehicle chargers can only charge a portable device battery at the vehicle battery's voltage when the vehicle is in start-up or ACC (Accessory On - ignition on) mode. Furthermore, these chargers can cause the vehicle battery to fully discharge if a portable device battery is charged while the vehicle is in ACC mode. Additionally, in-vehicle chargers are not designed to provide instantaneous charging of the vehicle battery's voltage.

[0004] From JP 2007 - 74 784 A, a vehicle-mounted charger for charging a battery of a portable device is known, comprising: a memory that stores a charge table in which ratios of the charge quantity of the battery of the portable device to voltage bandwidths of the vehicle battery are written; a voltage monitor that monitors the voltage of the vehicle battery at a predetermined time interval; a plug-in device of the portable device that receives the portable device and charges the battery of the portable device by the voltage of the vehicle battery;and a charging controller that detects the portable device being received through the portable device's plug and controls the portable device's plug so that the portable device's battery is charged by the vehicle battery's voltage to a voltage level that corresponds to the monitored vehicle battery voltage in the charging table.

[0005] The information disclosed above in this background section is intended only to improve the understanding of the background of the invention and may therefore contain information that does not constitute the prior art already known to a person skilled in the art in this country. SUMMARY

[0006] The task is therefore to provide a vehicle-mounted charger for charging a portable device's battery using a vehicle battery, which features improved charge control.

[0007] The problem is solved by a charger having the features of claim 1 and a method having the features of claim 11. Advantageous further developments are set out in the dependent claims.

[0008] One embodiment of the present invention provides a vehicle-mounted charger for charging the battery of a portable device using a vehicle battery. The device comprises a memory, a voltage monitor, a connector for the portable device, and a charging controller. The memory stores a charging table in which the ratios of the charge capacity of the portable device's battery to the voltage ranges of the vehicle battery are recorded. The voltage monitor monitors the voltage of the vehicle battery at a predetermined time interval. The connector for the portable device accepts the portable device and charges its battery using the voltage of the vehicle battery.The charging controller detects the portable device, which is connected via its plug, and controls the plug so that the portable device's battery is charged by the vehicle battery to a voltage value corresponding to the monitored vehicle battery voltage in the charging table. The charging controller is configured to fully charge the portable device's battery within a first voltage range, partially charge it within a second voltage range, and not charge it within a third voltage range. A further embodiment of the present invention provides a method for charging a portable device's battery with a vehicle battery.The procedure involves: monitoring the voltage of the vehicle battery by a voltage monitor; retrieving a charge ratio corresponding to the monitored voltage of the vehicle battery from a charge table, which specifies charge ratios to vehicle battery voltage ranges, when the portable device is detected by a charge controller; and charging the portable device's battery with the vehicle battery via a plug connector on the portable device until the portable device's battery is charged to a voltage level sufficient to meet the retrieved charge ratio.Charging the portable device includes the following: fully charging the portable device's battery in a first voltage bandwidth, partially charging the portable device's battery in a second voltage bandwidth, and not charging the portable device's battery in a third voltage bandwidth.

[0009] The above and further systems, methods, features, and advantages will be apparent to a person skilled in the art upon consideration of the following figures and the detailed description. It is intended that all such additional systems, methods, features, and advantages are included within this description, are within the scope of the invention, and are protected by the following claims. Nothing in this section should be considered a limitation of these claims. Further embodiments and advantages are explained below in connection with the embodiments. It should be noted that both the preceding general description and the following detailed description of the present application are exemplary and explanatory and are intended to provide a further explanation of the application as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are included to provide a better understanding of the embodiments and are incorporated into this application and form part thereof, represent embodiment(s) of the invention and, together with the description, serve to explain the application. The drawings include: Fig. Figure 1 shows a diagram of an arrangement of a charger mounted in a vehicle according to an embodiment of the present invention; Fig. 2 shows a flowchart of a method for charge control according to an embodiment of the present invention; Fig. Figure 3 shows a flowchart of a method for charge control according to a further embodiment of the present invention; and Fig. Figure 4 shows a diagram of an arrangement of a charger mounted in a vehicle according to a further embodiment of the present invention. DETAILED DESCRIPTION

[0011] The above-mentioned tasks, features, and advantages will become apparent to a person skilled in the art upon consideration of the following figures and the detailed description. As such, the technical aspects of the present invention can be easily implemented by a person skilled in the art. Likewise, the prior art known to a person skilled in the art is omitted from the description of the present invention in cases where it might unnecessarily obscure the subject matter of the present invention. Detailed reference will now be made to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0012] Fig. Figure 1 shows a diagram of an arrangement of a charger mounted in a vehicle according to an embodiment of the present invention.

[0013] As in Fig. As shown in Figure 1, a charger mounted in a vehicle comprises a memory 10, a voltage monitor 20, a plug-in device 30 of the portable device, an input / output unit 40, and a charging controller 50.

[0014] Memory 10 stores a charge table in which the ratios of the charge quantity of the portable device's battery are written with reference to the voltage ranges of a vehicle battery. Table 1 shows an example of the charge table. [Table 1] Vehicle battery voltage (V) Ratio of the charge quantity of the portable device's battery (%) Over 14 ~ under 14.7 100 Over 13 ~ under 14 92.8 Over 12 ~ under 13 85.7 Over 11 ~ under 12 78.5 Under 11 No charge

[0015] For clarification, a vehicle battery has a voltage of 14.7 V when fully charged and 9 V when fully discharged. The minimum voltage required to start the vehicle is approximately 10.5–11 V. Therefore, as shown in Table 1, the portable device's battery will not charge if the vehicle battery voltage is 11 V or less.

[0016] For example, let's assume the portable device is a mobile phone. A typical mobile phone battery (hereinafter referred to as the "mobile phone battery") has a voltage of 4.2V when fully charged and a voltage of 3V when fully discharged. The minimum voltage of the mobile phone battery is 3.3V, which is necessary for making calls.

[0017] In cases where the vehicle battery voltage is higher than 11V but not higher than 12V, if the mobile phone battery has a voltage higher than 3.3V before charging, charging will be prevented, and if the mobile phone battery has a voltage lower than 3.3V, it can only be charged to 3.3V, corresponding to 78.5% of its voltage at full charge (4.2V) according to Table 1.

[0018] Since the charging capacity of the vehicle battery is much greater than that of the mobile phone battery, the voltage of the vehicle battery will hardly drop below 11V, even if the vehicle battery with a voltage of 11V is used to increase the voltage of the mobile phone battery from 3.0V to 3.3V.

[0019] If the vehicle battery voltage is higher than 12V but not higher than 13V, the mobile phone battery can be charged to 3.6V, which corresponds to 85.7% of its full charge voltage, using the vehicle battery's voltage. However, if the mobile phone battery has a voltage higher than 3.6V before charging, charging will be prevented.

[0020] If the vehicle battery voltage is higher than 13V but not higher than 14V, the mobile phone battery can be charged to 3.9V, which corresponds to 92.8% of its full charge voltage, using the vehicle battery's voltage. However, if the mobile phone battery has a voltage higher than 3.9V before charging, charging will be prevented.

[0021] If the vehicle battery voltage is higher than 14V but not higher than 14.7V, the mobile phone battery can be charged to 4.2V, which corresponds to 100% of its full charge voltage, using the vehicle battery's voltage. However, if the mobile phone battery is already fully charged, charging will be prevented.

[0022] The voltage monitor 20 monitors the vehicle battery voltage in real time at a predetermined time interval and transmits the monitored result to the charging controller 50. For this purpose, the voltage monitor 20 includes a voltage measuring device configured to measure the vehicle battery voltage and an analog-to-digital converter (ADC) configured to convert the voltage measured by the voltage measuring device into a digital value. The voltage monitor 20 measures the vehicle battery voltage at a predetermined time interval and converts the measured voltage into the digital value. The converted digital value is then transmitted to the charging controller 50.

[0023] The connector 30 of the portable device transmits the voltage of the vehicle battery to the battery of the portable device according to the control of the charging controller 50. The connector 30 of the portable device also converts the voltage of the vehicle battery into a charging voltage for the battery of the portable device. The converted voltage is applied by the connector 30 to the battery of the portable device. The connector 30 of the portable device shields the converted voltage to be applied to the battery of the portable device according to the control of the charging controller 50 when the battery of the portable device is being charged, in order to maintain the preset charge ratios as shown in Table 1.

[0024] The input / output unit 40 comprises an input section equipped with a keypad, a touchscreen, and so on, and an output section equipped with a speaker, a display, and so on. The input / output unit 40, according to the charging controller 50, asks a question through the display and speaker as to whether charging is necessary. The input / output unit 40 also provides an answer, such as "yes" or "no," to the question posed by the driver (or user) via the input section. Furthermore, the input / output unit 40 either announces the current vehicle battery voltage via the speaker or displays the current vehicle battery voltage on a predetermined portion of the display screen, according to the charging controller 50.

[0025] When a portable device is connected to the portable device's connector 30, the charging controller 50 detects the portable device. If it is necessary to charge the portable device, the charging controller 50 controls the portable device's connector 30 so that the portable device's battery is charged to a voltage determined by the charging table stored in the memory 10, and the vehicle battery voltage is monitored by the voltage monitor 20.

[0026] The charging control unit 50 also controls the input / output unit 40 to output the voltage of the vehicle battery monitored by the voltage monitor 20 acoustically, visually or by both.

[0027] Alternatively, the charging controller 50 can check the voltage of the vehicle battery, which is monitored by the voltage monitor 20, and can control the connector 30 of the portable device to apply the voltage of the vehicle battery to the battery of the portable device until the voltage of the vehicle battery is reduced to a critical value (for example, 11V). The critical value is stored in memory 10 beforehand.

[0028] In this case, if the portable device's battery is fully charged before the vehicle battery voltage drops to a critical level, the charging of the portable device's battery can be prevented by an overcharge prevention function of the charging circuit within the portable device. A detailed description of the overcharge prevention function is omitted because it is well-known.

[0029] The charging controller 50 can obtain the ratio of the charge quantity of the battery of the portable device from a calculation module of the battery residual voltage provided in the portable device.

[0030] Fig. Figure 2 shows a flowchart of a method for charge control which can be used with the vehicle-mounted charger described above, according to an embodiment of the present invention.

[0031] A charge table including ratios of charge quantity for each of the voltage bandwidths of the vehicle battery is stored in memory 10 (step 201).

[0032] The voltage of the vehicle battery is monitored by the voltage monitor 20 (step 202).

[0033] When a portable device with a battery (which requires charging) is connected and detected, the charging controller 50 retrieves from the charging table in the memory 10 a ratio of the charge quantity according to the monitored voltage of the vehicle battery (step 203).

[0034] The plug-in device 30 of the portable device applies the voltage of the vehicle battery to the battery of the portable device until the battery of the portable device is charged according to the requested ratio of charge quantity (step 204).

[0035] The charging control unit 50 allows the monitored voltage of the vehicle battery to be output acoustically, visually, or by both.

[0036] Fig.Figure 3 shows a flowchart of a method for charge control which can be used with the vehicle-mounted charger described above, according to a further embodiment of the present invention.

[0037] A critical value (for example, 11V) for the vehicle battery is previously stored in memory 10 (step 301).

[0038] The voltage of the vehicle battery is monitored by the voltage monitor 20 (step 302).

[0039] When a portable device with a battery (requiring charging) is connected and detected, the charging controller 50 checks whether the vehicle battery voltage is higher than the critical value. If the vehicle battery voltage is higher than the critical value, the vehicle battery voltage is applied to the portable device battery (step 303). Conversely, if the vehicle battery voltage is not higher than the critical value, the vehicle battery voltage is not applied to the portable device battery.

[0040] If the voltage of the vehicle battery is reduced to the critical value (for example, 11V), the voltage applied to the battery of the portable device is shielded.

[0041] Fig.Figure 4 shows a diagram of an arrangement of a charging control (according to a further embodiment of the present invention).

[0042] A charger for a vehicle according to a further embodiment of the present invention, which is in Fig. Figure 4 shows the same structure as the embodiment of Fig. 1, except that it includes an AVN (Audio Video Navigation) link 60 instead of the input / output unit 40. As such, the load control 50 functions in Fig. 4 unlike those in Fig. 1. However, the memory 10, the voltage monitor 20 and the plug-in device 30 of the portable device in Fig. 4 the same function as those in Fig. 1. In addition, the charging controller included in the charger can handle 50 of Fig. 4. This is carried out by the vehicle's electronic control unit (ECU).

[0043] AVN Link 60 activates an AVN system (not shown) using an initial control signal from the load controller 50. When a user inputs a response, AVN Link 60 transmits a second control signal from the load controller 50 to the AVN system, thereby deactivating it. Alternatively, the AVN system can be implemented to operate in a different manner by adding a modified algorithm.

[0044] This means that the AVN system is activated by the first control signal, and when a response is entered by a user, the entered response is transmitted to the load controller 50 via the AVN link 60, whereby the activated AVN system is then automatically deactivated.

[0045] The charging controller 50 transmits the initial signal to the AVN system via the AVN link 60 to activate the AVN system. The charging controller 50 also receives a response, such as "yes" or "no," to a user's question about whether charging is necessary, via the AVN system and the AVN link 60, after the AVN link 60 and the AVN system have issued the question to the user. The charging controller 50 also allows the AVN system to output the vehicle battery's current voltage audibly, visually, or both, after the AVN system has been activated by transmitting the initial signal to it via the AVN link 60.In this case, the charging controller 50 can either activate the AVN system until a voltage to be applied to the battery of the portable device is shielded, or deactivate the AVN system by applying the second control signal to the AVN system after the instantaneous voltage of the vehicle battery is output audibly, visually or by both.

[0046] A typical, well-known AVN system comprises a user interface unit, an audio processor, a display unit, a control unit, and so on. The user interface unit includes a keypad and a touchscreen. The audio processor is used to output a variety of information via speech output. The display unit is used to show a variety of information on its screen. The control unit is used to control the operation of the AVN system.

[0047] The above methods according to the present invention can be provided in a computer program. Codewords and segments included in the program can be easily anticipated by programmers familiar with the prior art. The provided program is stored on a computer-readable recording medium (an information storage medium). As such, the program stored on the recording medium is read and executed by a computer, thus implementing the above method according to the present invention. The recording medium includes any type of computer-readable recording medium.

[0048] As described above, the devices and methods according to the present invention periodically monitor the voltage state of the vehicle battery and control the charge quantity of the portable device's battery based on the monitored voltage of the vehicle battery when a portable device with a battery that needs charging is detected, in order to enable the portable device's battery to be charged appropriately without causing a complete discharge of the vehicle battery.

[0049] It will be apparent to a person skilled in the art that a wide variety of modifications and variations are possible within a scope that does not lie outside the technical scope of the present invention. Therefore, it is intended that the present invention covers the modifications and variations of this invention, provided they fall within the scope of the appended claims and their equivalents.

Claims

A vehicle-mounted charger for charging a battery of a portable device, comprising: a memory (10) which stores a charge table in which ratios of the charge quantity of the battery of the portable device to voltage bandwidths of the vehicle battery are written; a voltage monitor (20) which monitors a voltage of the vehicle battery at a predetermined time interval; a plug device (30) of the portable device which receives the portable device and charges the battery of the portable device by the voltage of the vehicle battery;and a charging controller (50) that detects the portable device being received by the plug (30) of the portable device and controls the plug (30) of the portable device so that the battery of the portable device is charged by the voltage of the vehicle battery to a voltage value corresponding to the monitored voltage of the vehicle battery in the charging table, wherein the charging controller (50) is configured to fully charge the battery of the portable device in a first voltage range, to partially charge the battery of the portable device in a second voltage range, and not to charge the battery of the portable device in a third voltage range. A vehicle-mounted charger according to claim 1, wherein the charging controller (50) further controls the plug device (30) of the portable device to charge the battery of the portable device until the voltage of the vehicle battery is reduced to a critical voltage. A vehicle-mounted charger according to claim 1, which further comprises an output unit (40), wherein the charging controller (50) outputs the voltage of the vehicle battery through the output unit (40). A vehicle-mounted charger according to claim 1, wherein the voltage monitor (20) comprises: a voltage measuring device that measures the voltage of the vehicle battery; and an analog-to-digital converter that converts the measured voltage into a digital value. A vehicle-mounted charger according to claim 1, which further comprises an audio-video navigation link, wherein the charging controller (50) is connected to an audio-video navigation system by means of an audio-video navigation to output the voltage of the vehicle battery. A vehicle-mounted charger according to claim 2, which further comprises an output unit (40), wherein the charging controller (50) outputs the voltage of the vehicle battery through the output unit (40). A vehicle-mounted charger according to claim 2, wherein the voltage monitor (20) comprises: a voltage measuring device that measures the voltage of the vehicle battery; and an analog-to-digital converter that converts the measured voltage into a digital value. A vehicle-mounted charger according to claim 2, which further comprises an audio-video navigation link, wherein the charging control (50) is connected to an audio-video navigation system by means of an audio-video navigation to output the voltage of the vehicle battery. A vehicle-mounted charger according to claim 8, wherein the audio-video navigation linkage activates the audio-video navigation system using a first control signal from the charging controller (50), and deactivates the audio-video navigation system using a second control signal from the charging controller (50). A vehicle-mounted charger according to claim 9, wherein the charging control (50) activates the audio-video navigation system until the voltage to be applied to the battery of the portable device is shielded. Method for charging a battery of a portable device with a vehicle battery, comprising: monitoring the voltage of the vehicle battery by a voltage monitor (20); retrieving a quantity ratio of the charge according to the monitored voltage of the vehicle battery from a charge table in which quantity ratios of the charge to voltage ranges of the vehicle battery are written, when the portable device is detected by a charge controller (50);and charging the battery of the portable device with the vehicle battery through a plug device (30) of the portable device until the battery of the portable device is charged to a voltage value to satisfy the requested quantity ratio of the charge, wherein charging the portable device comprises: fully charging the battery of the portable device in a first voltage range, partially charging the battery of the portable device in a second voltage range, and not charging the battery of the portable device in a third voltage range. Method according to claim 11, further comprising enabling the monitored voltage of the vehicle battery to be output acoustically, visually or by both. Method according to claim 11, further comprising enabling the monitored voltage of the vehicle battery to be output acoustically, visually or by both by connecting to an audio-video navigation system via an audio-video navigation link. Method according to claim 13, wherein the audio-video navigation system is activated until loading is stopped.

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