Home | Links | Contact Us | More About Intellectual Property | Bookmark
Search patents:
Home Electrical and Wave Battery-charge-indicator

 Power control apparatus and method for a body implantable medical device
The present invention has certain objects. That is, various embodiments of the present invention ...


 Spread spectrum communication system utilizing differential code shift keying
The present invention is a spread spectrum data communication system that utilizes a modulation ...


 Voltage monitoring circuit for rechargeable battery
A voltage monitoring circuit and method for use in monitoring the voltage of a rechargeable battery ...


 Adaptive per-pair skew compensation method for extended reach differential transmission
What is claimed is: 1. A differential transmission de-skew system comprising: a first delay block; ...


 Time controlled battery charger
We claim as our invention: 1. In an on-board charger for an electric vehicle, the vehicle having a ...


 Method and apparatus for managing alternator loads on engines
The embodiments of the invention in which an exclusive property or privilege is claimed are defined ...


 Automatic polarity and condition sensing battery charger
The present invention discloses a battery charging device adapted to be connected to a battery ...


 Shunt resistance device for monitoring battery state of charge
What is needed therefore, is a device that minimizes the length of the conductors that connect the ...


 Battery state monitoring circuit
In order to solve the foregoing problem, according to the present invention, a circuit is added to ...


 System for supplying power to an apparatus and method for the assessment of the lifetime and capacity of a power-storage device
The invention claimed is: 1. An apparatus for assessing the lifetime and capacity of a power ...


 Battery charge indicator

Details
Inventors: Parsonage, Peter Cecil Joseph;
Assignee: Batteryguard Limited (Auckland, NZ)
Primary Examiner: Wong; Peter S.
Assistant Examiner: Tibbits; Pia
Attorney, Agent or Firm: Young Law Firm, P.C.

An automotive battery charge indicator uses an algorithm expressed by fixed component values to determine if the remaining charge in the battery has fallen below a predetermined threshold. A current sensing resistor (8) (may be a Hall effect sensor or a discrete component having a resistance of the same order of magnitude as the internal resistance of the monitored battery (1)) is connected in series with the positive terminal (2) of a lead acid battery (1), and the positive side of a non-critical load (4). A percentage of the voltage across the load detected as input (6) is compared by comparator (11) with a dynamic reference voltage at input (5). The dynamic reference voltage is made up of a fixed reference voltage (7) less the voltage drop through current sensing resistor (8). When the percentage of load voltage at (6) is less than the dynamic reference voltage at input (5), the comparator provides a negative output at (12) indicating that the remaining charge in the battery has fallen below the preset threshold value. The output from the comparator can be used to operate an indicator such as an LED, or it could be used to initiate circuit shutdown to protect the battery from being discharged excessively.

DETAILED DESCRIPTION What is claimed is: 1.
A battery charge monitoring means for deriving an indication of the state of charge of a defined type of battery, the monitoring means having: means for sensing a load voltage proportional to current flowing when a defined type of battery is connected to a load, a fixed reference voltage which is less than the maximum voltage of the defined type of battery to which the monitoring means is to be connected, current sensing means capable of providing a voltage output proportional to the voltage drop within the defined type of battery when under load as a result of the internal resistance of the defined type of battery, means for sensing a dynamic reference voltage comprising the fixed reference voltage minus the voltage output of the current sensing means, comparison means capable of comparing (a) the load voltage and (b) the dynamic reference voltage, to provide an output indicative of the state of charge of the battery.
2.
A battery charge monitoring means as claimed in claim 1, wherein the comparison means is connected to evaluation means capable of determining the state of charge of the battery based on an output from the voltage comparison means.
3.
A battery charge monitoring means as claimed in claim 1, wherein the comparison means comprises a comparator.
4.
A battery charge monitoring means as claimed in claim 1, wherein the current sensing means comprises a current sensing resistor having a resistance of the same order of magnitude as the internal resistance of the defined type of battery to which the monitoring means is to be connected.
5.
A battery charge monitoring means as claimed in claim 1, wherein the current sensing means comprises a Hall effect sensor.
6.
A battery charge monitoring means as claimed in claim 1, wherein the fixed reference voltage for a 12 volt 40 ampere-hour lead acid battery is about 2.
5 volts.
7.
Battery monitoring means as claimed in claim 1, wherein the monitoring means is connected to an automotive battery between a non-critical load and one of the battery terminals and includes at least one switching means in series with the non-critical load capable of connecting or disconnecting the non-critical load from the automotive battery, the switching means being controlled by an output from the comparison means


Related patents
  Tamper resistant circuit boards
The present invention satisfies this need by means of a physical barrier that also functions as a tampering sensor or sensors monitored by electrical circuitry that ...
  Auxiliary battery voltage/temperature compensation for automotive 12 volt system for electric vehicles
OF THE INVENTION Referring now to the drawings and more particularly to FIG. 1, shown thereat is an electrically powered motor vehicle 10 such as shown and described in ...
  Device for and method of switching and monitoring batteries
It is an object of the present invention to switch between parallel-connected batteries when the battery in use dies. It is another object of the present invention to ...
  Battery voltage measurement device
According to one aspect of the present invention, a battery voltage measurement device includes: a plurality of first switching sections, in which each pair of adjacent ...
  Method for failure detection in a radio frequency device
OF THE PREFERRED EMBODIMENT It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to ...
  Control device for the charging of at least one battery
The present invention seeks to overcome these drawbacks by using a control device that operates based on different principles. The control device of the invention relies ...
  Method for determining the state of charge of rechargeable batteries by integration of the amounts of current flowing during charging and discharging
Voltage U.sub.0L is the measured voltage when no current is flowing through the rechargeable battery, and which is produced after completion of a charging process. V...
  Portable power supply incorporating a generator driven by an engine
Features of the present invention improve conventional engine-driven generators in portable power supplies, and, in particular, enable an improved generator to operate ...
  Hardware modeling system and method of use
The present invention is an improved hardware modeling system and method of use. The hardware modeling system ("HMS") of the present invention is adaptable for ...
  Rechargeable battery protection circuit
The rechargeable battery protection circuit of the present invention is provided with a switching system connected in series with the rechargeable battery, a current ...

0.004

Archive: All patents - Links

Copyright (c)2006 Eipa-patents.org - All rights reserved