This has been an area of development where technology has provided the greatest solutions; however, this means a little more money is needed to provide them.

It used to be thought that voltage was a possible means of determining the capacity of charge left in a battery. This has not been found true and actually involves temperature and pressure considerations for precise determination. To deal with these complexities chips have been developed to stay "in-line" with the battery at all times to monitor incoming and outgoing current, temperature, and loss of capacity due to self-discharge and it's presence leaching power from the battery.

Hardware

• BatteryMonitoringComponents
• Smart Battery Microcontrollers
• MAX1780 - actually a microcontroller with I2C,SPI, ADCs doing coulomb-counting as a screen-saver
• Battery Monitoring Designs

Methods

• Crude (i.e. Voltage determination)

• Precise (i.e. Coulomb Counters)

• Article on battery-monitoring

-- RickJones - 01 Feb 2002