Electricity: battery or capacitor charging or discharging – One cell or battery charges another – Vehicle battery charging
Reexamination Certificate
1998-12-23
2001-07-17
Wong, Peter S. (Department: 2838)
Electricity: battery or capacitor charging or discharging
One cell or battery charges another
Vehicle battery charging
C320S122000
Reexamination Certificate
active
06262561
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a battery system, and especially to a battery system composed of a plurality of lithium battery modules connected to each other, for use in an electric vehicle.
The lithium battery has recently received considerable attention as a light-weight, high power-density battery with a large capacity, and which is suitable for use in an electric vehicle. However, since lithium batteries have a low tolerance level against over-charging and over-discharging, the misuse of a lithium battery may cause a fire or an explosion. Therefore, it is necessary to closely monitor and control the terminal voltage of a lithium battery.
A conventional battery system composed of a plurality of modules serially connected to each other, each module including cell batteries serially connected to each other, is disclosed, for example, in a paper “Advanced Battery System for Electric Vehicle,” EVS-13, Osaka, Japan. Each module is controlled in this battery system by a cell controller. A by-pass circuit is provided in each cell, and the cell controller controls each module so that any charging variation among the cells in each module is suppressed. The total battery system is controlled by a battery controller, and each cell controller sends signals to the battery controller.
As mentioned above, although the conventional battery system controls the charging-balance among the cells in each module, the system does not take the charging variation among the modules into consideration. However, in a battery system composed of many modules serially connected to each other, if there is a charging variation among the modules, the terminal voltage of only some of the modules attains the rated terminal voltage, and the terminal voltage of the rest of the modules remains under the rated terminal voltage, Accordingly, the full capacity of the battery system cannot be achieved. Furthermore, if there exists a charging variation among the modules, this also causes a variation in the length of their life cycles.
SUMMARY OF THE INVENTION
An object of the present invention is to suppress the charging variation among modules in a battery system.
The above object is attained by providing a by-pass circuit in each module and by controlling the by-pass circuit via a module-controlling circuit. Furthermore, the charging variation among the modules is reduced by controlling each by-pass circuit based on information bilaterally transmitted between each module-controlling circuit and a system-controlling circuit.
REFERENCES:
patent: 5153496 (1992-10-01), LaForge
patent: 5387857 (1995-02-01), Honda et al.
patent: 5504415 (1996-04-01), Podrazhansky et al.
patent: 5547775 (1996-08-01), Eguchi et al.
patent: 5557189 (1996-09-01), Suzuki et al.
patent: 5578914 (1996-11-01), Morita
patent: 5581170 (1996-12-01), Mammano et al.
patent: 5670861 (1997-09-01), Nor
patent: 5675233 (1997-10-01), Kaneko et al.
patent: 5677613 (1997-10-01), Perelle
patent: 5773957 (1998-06-01), Imaseki
patent: 5818201 (1998-10-01), Stockstad et al.
patent: 5886503 (1999-03-01), McAndrews et al.
patent: 5897973 (1999-04-01), Stephenson et al.
patent: 5932990 (1999-08-01), Kaneko
patent: 5945804 (1999-08-01), Hansson et al.
patent: 5998969 (1999-12-01), Tsuji et al.
patent: 195 45 833 (1995-12-01), None
patent: 814556A2 (1997-12-01), None
patent: 7-230829 (1995-08-01), None
patent: 09200968A (1997-07-01), None
patent: 0918237A (1997-07-01), None
patent: 9515604 (1995-06-01), None
T. Miyamoto et al., “Advanced Battery System for Electric Vehicle (FEV-II)”, EVS-13: The 13th Int'l Electric Vehicle Symposium, Oct. 13-16, 1996, Osaka, Japan.
Emori Akihiko
Kumashiro Yoshiaki
Miyazaki Hideki
Takahashi Tadashi
Antonelli Terry Stout & Kraus LLP
Hitachi , Ltd.
Tibbits Pia
Wong Peter S.
LandOfFree
Battery system and electric vehicle using the battery system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Battery system and electric vehicle using the battery system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Battery system and electric vehicle using the battery system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2525376