Power supply for powering an electric load of a vehicle

Abstract

The present invention relates to an electrical power supply system for powering an electric load of a vehicle comprises a main battery, a support battery and a battery control module. The battery control module comprises a first terminal for connection to said main battery, a second terminal for connection to said support battery and a third terminal for connecting to said electric load. Furthermore the module comprises a voltage comparator arranged to determine a voltage at the third terminal, and output a high output level when said determined voltage is less than a predetermined critical lowest voltage level. A first switch is arranged between said first terminal and said third terminal, said first switch being controllable by a first control signal. A second switch is arranged between said second terminal and said third terminal. The battery control module is arranged to connect the support battery to the load by turning the second switch conducting in case the voltage at the third terminal drops below a predetermined critical voltage. The invention provides the automatic activation of a support energy source when the output voltage falls below a specified voltage threshold. The support battery supports the main battery when needed or acts as a redundant power source. It is purely needed as a backup battery and not used in normal situations, so charging of this battery is less frequently needed, increasing its lifetime.

Description

technical field [0001] The invention relates to an electrical power supply system for supplying electrical loads of a vehicle, a battery control module and a vehicle comprising such an electrical power supply system. Background technique [0002] One way to save fuel in today's vehicles is to use the so-called auto-start-stop function, which shuts off the engine and restarts it automatically every time the vehicle comes to a complete stop moving forward, such as at a traffic light. Some relay functions in start-stop vehicles are affected more frequently than before, placing higher demands on reliability, control and diagnostics. In addition, very fast and high currents of various sequences are required. The voltage level of a vehicle's electrical system can vary widely, which creates a risk of failure of the electronic system. [0003] Patent application DE102010000656 describes a power supply system for a vehicle using two batteries. A power supply system for such a vehi...

AI Technical Summary

Problems solved by technology

In the system of DE102010000656, the two batteries are constantly charged and discharged, which will adversely affect the service life of the two batteries

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