Battery management system

1. An apparatus for power management of an aircraft, the apparatus comprising:

at least one memory;

instructions in the apparatus; and

processor circuitry to execute the instructions to:

in response to a disconnection of a battery string from a load, determine a quantity of current associated with the battery string based on a sensor measurement, the battery string including a plurality of batteries;

in response to a determination that the quantity of the current satisfies a threshold, identify ones of the plurality of the batteries to be coupled to the load based on respective charge states of the ones of the plurality of the batteries;

control a first switch to pre-charge the ones of the plurality of the batteries; and

in response to the pre-charging of the ones of the plurality of the batteries, control a second switch to couple the ones of the plurality of the batteries to at least one of the load or a solar panel, the solar panel to charge the ones of the plurality of the batteries.

2. The apparatus of claim 1 , wherein the threshold is a first threshold, the ones of the plurality of the batteries including a first battery, a second battery, and a third battery, the determination is a first determination, and the processor circuitry is to execute the instructions to:

determine a first charge state of the first battery;

determine a second charge state of the second battery;

determine a third charge state of the third battery;

determine whether a sum of at least one of the first charge state, the second charge state, or the third charge state satisfies a second threshold; and

in response to a second determination that the sum of the first charge state and the second charge state satisfies the second threshold:

control a third switch to couple the first battery to the first switch and the second switch, the third switch coupled to the first battery;

control a fourth switch to couple the second battery to the first switch and the second switch, the fourth switch coupled to the second battery; and

control a fifth switch to disconnect the third battery from the first switch and the second switch, the fifth switch coupled to the third battery.

3. The apparatus of claim 1 , wherein the threshold is a first threshold, the charge states are first charge states, the determination is a first determination, and the processor circuitry is to execute the instructions to:

determine a first voltage associated with a motor of the aircraft, the motor coupled to a propulsor of the aircraft;

determine a second voltage based on respective second charge states of the ones of the plurality of the batteries; and

in response to a second determination that a difference between the first voltage and the second voltage satisfies a second threshold, identify a fault condition associated with the ones of the plurality of the batteries.

4. The apparatus of claim 3 , wherein the fault condition is a first fault condition, and the processor circuitry is to execute the instructions to:

determine a rate of change of the difference; and

in response to a third determination that the rate of change satisfies a third threshold and the difference satisfies a fourth threshold:

determine whether a time period has elapsed;

in response to a fourth determination that the time period has elapsed, identify a second fault condition; and

control the first switch to discontinue the pre-charging of the ones of the plurality of the batteries by switching the first switch from a closed position to an open position.

5. The apparatus of claim 1 , wherein the processor circuitry is to execute the instructions to, in response to the determining that the quantity of the current satisfies the threshold and a time period has elapsed:

identify a fault condition associated with the disconnecting of the battery string from the load; and

control the first switch to halt the pre-charging of the ones of the plurality of the batteries.

6. The apparatus of claim 1 , wherein the processor circuitry is to execute the instructions to, in response to the controlling of the second switch to couple the ones of the plurality of the batteries to the load:

identify a fault condition of a first battery of the ones of the plurality of the batteries;

control a third switch to bypass the first battery from the load; and

control a fourth switch to couple a second battery of the plurality of the batteries to the load, the second battery not included in the ones of the plurality of the batteries.

7. The apparatus of claim 1 , wherein the plurality of the batteries are included in a first battery bank, and the processor circuitry is to execute the instructions to:

identify a fault condition of the first battery bank;

control a third switch to bypass the first battery bank from the at least one of the load or the solar panel; and

control a fourth switch to couple a second battery bank to the load.

8. The apparatus of claim 1 , wherein the processor circuitry is to execute the instructions to, in response to not identifying a fault condition based on the pre-charging the ones of the plurality of the batteries, control the second switch to couple the ones of the plurality of the batteries to the solar panel to charge the ones of the plurality of the batteries.

9. The apparatus of claim 1 , wherein the threshold is a first threshold, the determination is a first determination, and the processor circuitry is to execute the instructions to:

control a third switch to couple a first battery of the plurality of the batteries to the load;

determine an output voltage provided to the load; and

in response to a second determination that the output voltage does not satisfy a second threshold, control a fourth switch to couple a second battery of the plurality of the batteries to the load, the coupling of the second battery to the load to cause the second threshold to be satisfied.

10. A storage disc or storage device comprising instructions that, when executed, cause processor circuitry to:

in response to a disconnection of a battery string from a load, determine a quantity of current associated with the battery string based on a sensor measurement, the battery string including a plurality of batteries;

in response to a determination that the quantity of the current satisfies a threshold, identify ones of the plurality of the batteries to be coupled to the load based on respective charge states of the ones of the plurality of the batteries;

control a first switch to pre-charge the ones of the plurality of the batteries; and

in response to the pre-charging of the ones of the plurality of the batteries, control a second switch to couple the ones of the plurality of the batteries to at least one of the load or a solar panel, the solar panel to charge the ones of the plurality of the batteries.

11. The storage disc or storage device of claim 10 , wherein the threshold is a first threshold, the ones of the plurality of the batteries including a first battery, a second battery, and a third battery, the determination is a first determination, and the instructions, when executed, cause the processor circuitry to:

determine a first charge state of the first battery;

determine a second charge state of the second battery;

determine a third charge state of the third battery;

determine whether a sum of at least one of the first charge state, the second charge state, or the third charge state satisfies a second threshold; and

in response to a second determination that the sum of the first charge state and the second charge state satisfies the second threshold:

control a third switch to couple the first battery to the first switch and the second switch, the third switch coupled to the first battery;

control a fourth switch to couple the second battery to the first switch and the second switch, the fourth switch coupled to the second battery; and

control a fifth switch to disconnect the third battery from the first switch and the second switch, the fifth switch coupled to the third battery.

12. The storage disc or storage device of claim 10 , wherein the threshold is a first threshold, the charge states are first charge states, the determination is a first determination, and the instructions, when executed, cause the processor circuitry to:

determine a first voltage associated with a motor of an aircraft, the motor coupled to a propulsor of the aircraft;

determine a second voltage based on respective second charge states of the ones of the plurality of the batteries; and

in response to a second determination that a difference between the first voltage and the second voltage satisfies a second threshold, identify a fault condition associated with the ones of the plurality of the batteries.

13. The storage disc or storage device of claim 12 , wherein the fault condition is a first fault condition, and the instructions, when executed, cause the processor circuitry to:

determine a rate of change of the difference; and

in response to a third determination that the rate of change satisfies a third threshold and the difference satisfies a fourth threshold:

determine whether a time period has elapsed;

in response to a fourth determination that the time period has elapsed, identify a second fault condition; and

control the first switch to discontinue the pre-charging of the ones of the plurality of the batteries by switching the first switch from a closed position to an open position.

14. The storage disc or storage device of claim 10 , wherein the instructions, when executed, cause the processor circuitry to, in response to the determining that the quantity of the current satisfies the threshold and a time period has elapsed:

identify a fault condition associated with the disconnecting of the battery string from the load; and

control the first switch to halt the pre-charging of the ones of the plurality of the batteries.

15. The storage disc or storage device of claim 10 , wherein the instructions, when executed, cause the processor circuitry to, in response to the controlling of the second switch to couple the ones of the plurality of the batteries to the load:

identify a fault condition of a first battery of the ones of the plurality of the batteries;

control a third switch to bypass the first battery from the load; and

control a fourth switch to couple a second battery of the plurality of the batteries to the load, the second battery not included in the ones of the plurality of the batteries.

16. A method for power management of an aircraft, the method comprising:

in response to disconnecting a battery string from a load, determining a quantity of current associated with the battery string based on a sensor measurement, the battery string including a plurality of batteries;

in response to determining that the quantity of the current satisfies a threshold, identifying ones of the plurality of the batteries to be coupled to the load based on respective charge states of the ones of the plurality of the batteries;

controlling a first switch to pre-charge the ones of the plurality of the batteries; and

in response to the pre-charging of the ones of the plurality of the batteries, controlling a second switch to couple the ones of the plurality of the batteries to at least one of the load or a solar panel, the solar panel to charge the ones of the plurality of the batteries.

17. The method of claim 16 , wherein the sensor measurement is a first voltage measured by a sensor associated with a first battery of the ones of the plurality of the batteries, and further including:

converting, with an amplifier coupled to the sensor, the first voltage to a second voltage, the second voltage less than the first voltage;

delivering, with a multiplexer coupled to the amplifier, the second voltage to a converter;

converting, with the converter, the second voltage to a digital output; and

delivering, with a digital isolator coupled to the converter, the digital output to a controller, the controller to determine the quantity of the current based on the digital output.

18. The method of claim 16 , wherein the threshold is a first threshold, the ones of the plurality of the batteries including a first battery, a second battery, and a third battery, and further including:

measuring a first charge state of the first battery;

measuring a second charge state of the second battery;

measuring a third charge state of the third battery;

determining whether a sum of at least one of the first charge state, the second charge state, or the third charge state satisfies a second threshold; and

in response to determining that the sum of the first charge state and the second charge state satisfies the second threshold:

controlling a third switch to couple the first battery to the first switch and the second switch, the third switch coupled to the first battery;

controlling a fourth switch to couple the second battery to the first switch and the second switch, the fourth switch coupled to the second battery; and

controlling a fifth switch to disconnect the third battery from the first switch and the second switch, the fifth switch coupled to the third battery.

19. The method of claim 16 , wherein the threshold is a first threshold, the charge states are first charge states, and the pre-charging of the ones of the plurality of the batteries includes:

determining a first voltage associated with a motor of the aircraft, the motor coupled to a propulsor of the aircraft;

determining a second voltage based on respective second charge states of the ones of the plurality of the batteries; and

in response to determining that a difference between the first voltage and the second voltage satisfies a second threshold, identifying a fault condition associated with the ones of the plurality of the batteries.

20. The method of claim 19 , wherein the fault condition is a first fault condition, and further including:

determining a rate of change of the difference; and

in response to determining that the rate of change satisfies a third threshold and the difference satisfies a fourth threshold:

determining whether a time period has elapsed;

in response to determining that the time period has elapsed, identifying a second fault condition; and

controlling the first switch to discontinue the pre-charging of the ones of the plurality of the batteries by switching the first switch from a closed position to an open position.