Systems and methods for managing a battery pack
A battery controller includes a first driving pin, a second driving pin and a third driving pin. The first driving pin is coupled to a charge switch and is operable for turning on the charge switch to enable a battery pack to be charged by a power source. The second driving pin is coupled to a first discharge switch and is operable for turning on the first discharge switch to enable the battery pack to power a first load. The third driving pin is coupled to a second discharge switch and is operable for turning on the second discharge switch to enable the battery pack to power a second load.
1. A battery management system for managing a battery pack comprising a first plurality of battery cells and a second plurality of battery cells, said battery management system comprising:
a master controller operable for monitoring and managing said first plurality of battery cells, wherein said master controller consumes a first current from said first plurality of battery cells; and
a slave controller operable for monitoring and manacling said second plurality of battery cells, wherein said slave controller consumes a second current from said second plurality of battery cells,
wherein said master controller comprises:
a communication port, coupled to said slave controller, operable for receiving a signal indicating an amount of said second current consumed by said slave controller and operable for transmitting a balancing command to said slave controller to adjust said second current;
wherein said battery management system further comprises:
a first discharge loop comprising a first discharge switch that is configured to be coupled to a first load; and
a second discharge loop comprising a second discharge switch that is configured to be coupled to a second load; and
wherein said master controller is operable for outputting driving signals to control said first discharge switch and said second discharge switch.
2. The battery management system of claim 1 , further comprising:
a resistor coupled to said first discharge loop and said second discharge loop for sensing a first discharge current in said first discharge loop and a second discharge current in said second discharge loop, wherein both said first discharge current and said second discharge current flow through said resistor.
3. The battery management system of claim 1 , wherein said slave controller comprises:
a current sensor, operable for sensing said second current; and
a current-controlled oscillator, coupled to said current sensor, operable for generating said signal based on said second current, wherein a frequency of said signal is proportional to said second current.
4. The battery management system of claim 1 , wherein said master controller is operable for transmitting a balancing command to said slave controller to adjust said second current.
5. The battery management system of claim 4 , wherein said slave controller comprises:
a module balance circuit operable for adjusting said second current according to said balancing command from said master controller.
6. The battery management system of claim 5 , wherein said module balance circuit includes a variable resistor, wherein said slave controller increases a resistance of said variable resistor to increase said second current if said second current is less than said first current.