Electric vehicle

• US 6,390,215 B1
• Filed: 05/29/1999
• Issued: 05/21/2002
• Est. Priority Date: 05/29/1998
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Kodama, Hiroki, Ishii, Yukihisa, Ei, Ryoji
• Primary Examiner(s): Mai, Lanna
• Assistant Examiner(s): RESTIFO, JEFFREY J
• Application Number:
  US09/322,898
• Time in Patent Office: 1,088 Days
• Field of Search: 180/2.1, 180/65.3, 180/68.5, 180/2.2, 320/104
• US Class Current: 180/65.22
• CPC Class Codes: B60K 1/04 of the electric storage means for propulsion exchanging batteries for electric propulsion of vehicles B60L53/80; for auxiliary purposes only B60R16/04; supplying batteries to, or removing batteries from, vehicles B60S5/06
• CPC Class Codes: B60L 2200/28 Trailers
• CPC Class Codes: B60L 50/62 charged by low-power generators primarily intended to support the batteries, e.g. range extenders
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

An electric vehicle includes a main battery mounted on a vehicle body and a sub-battery detachably connected to the vehicle body. The electric vehicle travels with the electric power of the main battery in the case where the traveling distance is not long. In the case where the traveling distance is long, a trailer with the sub-battery is coupled to the rear of the electric vehicle, so that both the electric powers of the two batteries are used to drive an electric motor to allow the electric vehicle to travel. At the time of driving of the motor, the electric power of the sub-battery is preferentially used. When the sub-battery becomes completely discharged, the trailer is disconnected from the electric vehicle. In this case, with the vehicle body weight reduced, the traveling of the electric vehicle with the electric power of the main battery can be continued, and therefore the total traveling distance is further increased. At the time of regeneration of electrical energy by the motor during braking operations, the main battery is preferentially charged with the regenerative power, so that the electric power of the main battery is maintained as long as possible.

Claims

1. An electric vehicle comprising:

a main battery mounted on a vehicle body;

a trailer detachably connected to said electric vehicle;

a sub-battery disposed in said trailer;

an electric motor-generator electrically connected to said main battery and said sub-battery for being powered thereby to generate a traveling drive force, and which generates a regenerative brake force at deceleration of the vehicle body; and

control means for controlling drive and regeneration operation of said motor-generator, wherein, when said sub-battery is connected to the vehicle body, said control means controls said motor-generator so that;

(i) said motor-generator preferentially first uses an electric power of said sub-battery, before using an electric power of said main battery, for powering said motor-generator and (ii) said motor-generator preferentially first charges said main battery, before charging said sub-battery, by a regenerative power generated by said motor-generator.

2. An electric vehicle according to claim 1, wherein the driving of said motor-generator by said main battery is started after said sub-battery has been substantially completely discharged.

3. An electric vehicle according to claim 1, wherein a charging of said sub-battery by the regenerative power is started after said main battery has been completely charged.

4. An electric vehicle according to claim 1, wherein said sub-battery is mounted on a trailer which is detachably coupled to said vehicle body.

5. An electric vehicle according to claim 1, wherein said sub-battery has a larger capacity than said main battery.

6. An electric vehicle according to claim 1, wherein:

(i) said motor-generator preferentially uses the electric power of said sub-battery for driving said motor-generator until a charge state of said sub-battery drops below a first predetermined level, and then said motor-generator uses electric power from said main battery; and

(ii) said motor-generator preferentially charges said main battery by a regenerative power generated by said motor-generator until a charge state of said main battery reaches a second predetermined level, and then said motor-generator charges said sub-battery.

7. An electric vehicle and trailer assembly, comprising:

a vehicle support frame;

at least one drive wheel rotatably connected to said vehicle support frame;

a main battery carried by said vehicle support frame;

a motor-generator carried by said vehicle support frame for operatively rotating said drive wheel during acceleration of said vehicle, and for generating electricity during braking of said vehicle, said motor-generator being in electrical communication with said main battery;

a controller associated with said vehicle support frame for controlling operation of said motor-generator; and

a trailer which is detachably and releasably connectable to said electric vehicle, said trailer comprising;

a trailer body which is detachably connectable to said vehicle support frame;

a sub-battery carried by said trailer body, said sub-battery being in electrical communication with said motor-generator;

wherein, during acceleration of said vehicle, said controller operates to draw power primarily from said sub-battery, to drive said motor-generator, until a charge state of said sub-battery falls below a first predetermined level, at which time said controller switches to draw power from said main battery to drive said motor-generator;

and further wherein, during regenerative braking of said vehicle, said controller operates to send power, from said motor-generator, primarily to said main battery, until a charge state of said main battery exceeds a second predetermined level, at which time said controller operates to send power from said motor-generator to said sub-battery.