1. EE330 Final Project Lithium Battery Monitor Evan Adkins and Brandon Umscheid

2. Purpose of Project The purpose of this project is to take all of the knowledge gained through the EE330 labs and put it to use in a practical application.

3. Introduction Design an integrated circuit for a rechargeable battery station. Three rechargeable batteries are placed into a recharging station and the design should make sure that voltage, current, and temperature are monitored to maintain safe charging of the batteries. The system should safely charge batteries and not allow them to be in unsafe recharging operation(i.e. blow up) It should also give display outputs that show the operating modes of the recharging station as well as the combined battery voltage level. The system will also communicate with an external controller that can request information from the recharging station(i.e. battery voltage, current, temperature, etc.).

4. Description of Operation Modes Normal Mode—The battery is connected to the system and is allowed to charge or discharge through the protection relay. The system will read the voltage on each individual cell, the current, and the temperature continuously and save the values into the registers. Warning Mode—The battery pack is approaching one or more of its safety limits. It should continue to read the battery sensors and save the values, as well as alert the controller the nature of the warning (low voltage, high voltage, high temperature, etc.)

5. Description Continued Failure Mode—One or more of the battery parameters has left the safe region, and the system shuts off the relay to isolate the batteries. Also, it will alert the controller that a failure has occurred and indicate the type of failure. Once in Failure Mode, it will remain there until the batteries are safely within their operating parameters again (within the limits for the Warning Mode) and receive an acknowledgment from the controller.

6. Safety Criteria

7. State Machine with Fault Status Status Code 00: Normal 01: Warning 10: Failure 11: DNE Status = 00, 11 Status = 01, 11 Normal Mode 3.2<V<4.1 -1.5<I<3 5<Temp<35 Warning Mode V =4.1 I =3 Temp =35 Initial State RST = 0 Failure Mode V =4.2 I =4 Temp =40 Status = 10, 11 Status = 10 Status = 00 Status = 01

8. Normal Mode Levels as described in state machine. Charging Status light will be green showing normal charging operations. Battery level LEDs will all be off for lowest voltage level, or all green for highest battery voltage. (9 to 12.3 V). Output screen should be blank because there are no warnings. System operates regularly Battery Level System Status Output controller Screen Reset

9. Warning Mode Levels as described in state machine. Charging Status light will be yellow meaning some parameters are reaching dangerous levels Output screen will display warnings: – Low/High Temperature Warning – Low/High Voltage Warning – High Charging Current Warning – High Discharging Current Warning System will continue charging operations Battery Level System Status Output controller Screen Reset

10. Failure Mode Levels as described in state machine. Charging Status light will be red meaning some parameters are at dangerous levels Output screen will display warnings: – Low/High Temperature Failure – Low/High Voltage Failure – High Charging Current Failure – High Discharging Current Failure System will shut off and discontinue charging until parameters are back within safe limits Battery Level System Status Output controller Screen Reset

11. Simulation

12. Questions