Battery management system

1 . A method of discharging a battery assembly, comprising:

detecting, with aid of a timer, when the battery assembly is not in use for a threshold length of time, the battery assembly being configured to power at least a part of a movable object;

initiating, with aid of one or more processors individually or collectively, a controlled self-discharge of the battery assembly in response to a signal indicative of the battery assembly being not in use for the threshold length of time, the controlled self-discharge comprising a decrease of a voltage of the battery assembly to a preset voltage value, the controlled self-discharge being performed with a self-discharging circuit electrically coupled to the battery assembly,

wherein the self-discharging circuit includes a self-discharging resistor and a control switch, together both connected in parallel with positive and negative terminals of the battery assembly, the controlled self-discharge is initiated when the control switch is switched to a closed state and is terminated when the control switch is switched to an open state, and the controlled self-discharge is carried out by the self-discharging resistor controlled by the control switch.

2 . The method of claim 1 , further comprising:

determining, in response to determining that substantially no current is flowing from the battery assembly to the movable object, the battery assembly is not in use.

3 . The method of claim 1 , further comprising:

starting the timer in response to a battery management system detecting that power to the movable object is turned off.

4 . The method of claim 1 , further comprising:

terminating the controlled self-discharge of the battery assembly when the battery assembly voltage reaches the preset voltage value.

5 . The method of claim 4 , wherein the preset voltage value is configured to enable safe long-term storage of the battery assembly.

6 . The method of claim 4 , further comprising:

entering a hibernation mode subsequent to terminating the controlled self-discharge of the battery assembly when the battery assembly voltage reaches the preset voltage value.

7 . The method of claim 6 ,

wherein the hibernation mode is a low power consumption mode;

the method further comprising:

in the hibernation mode, monitoring whether the battery assembly is activated.

8 . The method of claim 7 , further comprising:

exiting the hibernation mode in response to the battery assembly being activated, wherein the battery assembly is activated in response to at least one of: a power switch being activated, power to the movable object being switched on, or the battery assembly being charged.

9 . The method of claim 1 , wherein the movable object is an unmanned aerial vehicle (UAV).

10 . The method of claim 9 , wherein the battery assembly is onboard the UAV.

11 . An apparatus for discharging a battery assembly, comprising:

a timer configured to detect an amount of time that the battery assembly is not in use since a signal is received from a movable object and configured to indicate that power to the movable object is turned off for storage of the movable object, the battery assembly being configured to power at least a part of the movable object;

one or more processors individually or collectively configured to:

receive a signal from the timer indicative of the amount of time, and

generate a signal that initiates a controlled self-discharge of the battery assembly when the amount of time exceeds a threshold length of time; and

a self-discharging circuit electrically coupled to the battery assembly and configured to, in response to receiving the signal that initiates the controlled self-discharge of the battery assembly, decrease a voltage of the battery assembly to a preset voltage value;

wherein the self-discharging circuit includes a self-discharging resistor and a control switch, together both connected in parallel with positive and negative terminals of the battery assembly, and the controlled self-discharge is initiated when the control switch is switched to a closed state and is terminated when the control switch is switched to an open state and the controlled self-discharge is carried out by the self-discharging resistor controlled by the control switch.

12 . The apparatus of claim 11 , wherein the one or more processors individually or collectively are further configured to generate a signal that terminates the controlled self-discharge of the battery assembly in response to at least one of: (1) the battery assembly being in use, or (2) the voltage of the battery assembly reaching the preset voltage value.

13 . The apparatus of claim 12 , wherein the preset voltage is configured to enable safe long-term storage of the battery assembly.

14 . The apparatus of claim 12 , wherein the one or more processors individually or collectively are further configured to generate a signal that enters the battery assembly into a hibernation mode subsequent to terminating the controlled self-discharge of the battery assembly when the voltage of the battery assembly reaches the preset voltage value.

15 . The apparatus of claim 11 , wherein the battery assembly is used to power a propulsion system of an unmanned aerial vehicle (UAV).

16 . The method of claim 1 , wherein prior to the battery assembly voltage reaching the preset voltage value, the controlled self-discharge of the battery assembly is terminated in response to detecting that the battery assembly is activated or detecting that the movable object is powered on or detecting that current is flowing from the battery assembly to the one or more components of the movable object.

17 . The method of claim 1 , wherein the battery assembly is one of a plurality of battery assemblies each of which is electrically coupled to a corresponding self-discharging circuit, and each self-discharging circuit is individually controlled to initiate or terminate the controlled self-discharge of the corresponding battery assembly.