Vehicle power supply device
First Claim
1. A vehicle power supply device, comprising a secondary battery, a capacitor connected parallel to said secondary battery, a relay interposed between said secondary battery and said capacitor, and relay control means for open-controlling said relay after a key is switched OFF,the vehicle power supply device further comprising polarization estimating means for estimating a polarization condition of said secondary battery after said key has been switched OFF,wherein said relay control means opens said relay when polarization in said secondary battery is estimated to have been eliminated by said polarization estimating means.
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Accused Products
Abstract
The present invention provides a vehicle power supply device that is capable of suppressing deterioration of a capacitor, shortening a precharging time, and suppressing power loss. An ECU estimates a polarization condition of a battery after a key has been switched OFF (IG SW_OFF), and opens a main relay after determining that the polarization condition of the battery has been eliminated. Thus, a voltage difference between a battery voltage and a capacitor voltage when the main relay is subsequently reconnected can be reduced. Hence, even when the capacity of the capacitor is increased, the time required for precharging can be shortened, and energy regeneration and so on can be realized efficiently within a short time period after switching the key ON. In this case, a situation in which the post-release capacitor voltage is maintained at an unnecessarily high level can be prevented even when charging polarization occurs in the battery, and as a result, deterioration of the capacitor can be suppressed.
23 Citations
6 Claims
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1. A vehicle power supply device, comprising a secondary battery, a capacitor connected parallel to said secondary battery, a relay interposed between said secondary battery and said capacitor, and relay control means for open-controlling said relay after a key is switched OFF,
the vehicle power supply device further comprising polarization estimating means for estimating a polarization condition of said secondary battery after said key has been switched OFF, wherein said relay control means opens said relay when polarization in said secondary battery is estimated to have been eliminated by said polarization estimating means.
Specification