Resources Contact Us Home
Battery charge monitor and fuel gauge

Image Number 7 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
Mask and method for forming the mask
Hermetically sealed atomic sensor package manufactured with expendable support structure
Automated gate system
Intraoral camera for dental chairs
High electron mobility transistor and manufacturing method thereof
System and method to obtain signal acquisition assistance data
Use of beta-adrenoceptor antagonists for the manufacture of a medicament of the treatment of disorders of the outer retina
  Randomly Featured Patents
Suspension device for a container
Enhancement-depletion Darlington device
Process for producing tire rubber modified asphalt cement systems and products thereof
Child seat base
Compressor discharge valve having a guided spherical head
Progressive ultrasonic welding system
Device for cooling the bits of a cutting machine
Method and apparatus for playing games between the clients of entities at different locations
Graphics display system with unified memory architecture
Silo unloader