Battery internal temperature sensing battery management system

1. A battery management system comprising:

a processor;

a multiplexer;

a second multiplexer;

a current source; and

a measurement circuit,

the measurement circuit being electrically coupled to the processor, and the measurement circuit comprising a gain circuit, a second gain circuit, a buffer, and a root means square converter, the first and second gain circuits increasing the amplitude of a signal received from the multiplexer and the root means square converter converting the signal received from the multiplexer into a direct current signal of equivalent value,

the battery management system is configured to:

send a first command signal to the multiplexer to cause the multiplexer to select a cell of a battery;

send a second command signal to the current source to apply a current to the cell of the battery;

send a third command signal to the second multiplexer to cause the second multiplexer to select a current path, the first and command signals being synchronous commands; and

receive measurement information based on the application of the current to the cell from the measurement circuit.

2. The battery management system of claim 1 , wherein the measurement information comprises a cell voltage corresponding to the cell of the battery.

3. The battery management system of claim 1 , wherein the measurement information comprises a phase shift measurement corresponding to the cell of the battery.

4. The battery management system of claim 1 , wherein the measurement information comprises a cell impedance corresponding to the cell of the battery.

5. A system comprising:

a multiplexer configured to select a cell of a battery;

a current source configured to apply a current to the cell of the battery;

a second multiplexer configured to select a current path from the current source to the cell of the battery, the multiplexer and the second multiplexer operating synchronously to select the cell of the battery and select the current path from the current source to the cell of the battery, respectively;

a measurement circuit configured to output measurement information based on the application of the current to the cell, the measurement circuit being electrically coupled to a microcontroller, and the measurement circuit comprising a gain circuit, a second gain circuit, a buffer, and a root means square converter; and

the microcontroller configured to control the operations of the multiplexer and current source via sending command signals comprising the first and second gain circuits increasing the amplitude of a signal received from the multiplexer and the root means square converter converting the signal received from the multiplexer into a direct current signal of equivalent value.

6. The system of claim 5 , wherein the measurement information comprises one or more of a cell voltage corresponding to the cell of the battery, a phase shift measurement corresponding to the cell of the battery, a cell impedance corresponding to the cell of the battery.

7. The battery management system of claim 1 , wherein the measurement circuit measures an amplitude and a phase shift of a cell impedance at multiple frequencies corresponding to the cell of the battery to characterize the cell regarding states of an anode, a cathode, and an electrolyte.

8. The battery management system of claim 7 , wherein the measurement circuit couples the amplitude and the phase shift of the cell impedance at the multiple frequencies with a direct current cell voltage measurement to cause battery safety and energy management by the battery management system.