Resources Contact Us Home
Battery charge monitor and fuel gauge

Image Number 11 for United States Patent #5315228.

A battery charge controller and fuel gauge which accurately monitors the voltage, temperature, and charge and discharge current of a rechargeable battery, and calculates the battery's charge capacity and charge level. Each time the battery is fully discharged, any calculated charge level remaining is divided by two and subtracted from the previously calculated charge capacity. When the battery is fully charged, the charge level is set equal to the charge capacity. During subsequent charge and discharge, the current is converted to a coulomb count and added or subtracted from the charge level to maintain an accurate charge level. Fast charge inefficiency due to temperature is considered by subtracting a temperature proportional factor before the charge level of the battery is updated. The charge level, voltage and temperature are used to determine the optimal fast charge termination point to achieve full charge and prevent temperature abuse and overcharge. A fast charge is applied only if the battery is within proper voltage and temperature ranges. The charge controller includes a microcontroller circuit within the same battery pack as the battery, which is powered by the battery when AC power is unavailable. The microcontroller circuit consumes very little power, measures circuit errors to assure data accuracy, times periods of self-discharge and updates the charge level accordingly. The microcontroller circuit also includes memory to store the battery charge information and a communication port to provide the charge information to a computer system connected to the battery pack.

  Recently Added Patents
Method and apparatus for transmitting and receiving a signal in a communication system
Biodegradable aliphatic-aromatic copolyester for use in nonwoven webs
Flexible pouch
System and method for hybrid risk modeling of turbomachinery
LED string with a capability to maintain a current path and LED unit thereof
Light transformation particle and photobioreactor
  Randomly Featured Patents
Liquid crystal module and method for assembling thereof
Adjustable height stove guard
Fixing toner images in electrophotography
Systems and methods for the automatic registration of devices
Measurement arrangement for calibrating ultrasonic shock wave sensors
Circuit for overvoltage protection
Reusable flyback rocket booster and method for recovering same
Method for identifying a nucleotide base pair at a point mutation site in a DNA target using a mismatch repair enzyme
Process for preparing aminoanthraquinones
Control arrangement for at least two hydraulic consumers and pressure differential valve for said control arrangement