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
Piano keyboard with key touch point detection
MEMS structure and method for making the same
Pet grooming brush and vacuum attachment
Integrated circuit packaging system with heat slug and method of manufacture thereof
Identifying multi-component carrier cells
High electron mobility transistor and manufacturing method thereof
Disk array apparatus and firmware update method therefor
  Randomly Featured Patents
Candle wax stabilized by a combination of UV absorber plus a selected hindered amine
Wall mount assembly
Electronic cooling system having a ventilating duct
Highway collision containment system
Safety device for liquid aerating apparatus
Cordless vibrating massager
Surface topography method for determining effects of a botulinum toxin upon a muscle and for comparing botulinum toxins
Vehicle wheel condition monitor and data storage system
Method, apparatus and computer program products for determining quantities of nucleic acid sequences in samples
Automobile tire