Parameters of the BMS

Parameter

Unit

Datatype

Description

Default

RO/RW

No

c-batt

C

float

The temperature of the external battery temperature sensor

0

RO

0

v-out

V

float

The voltage of the BMS output

0

RO

1

v-batt

V

float

The voltage of the battery pack

0

RO

2

i-batt

A

float

The last recorded current of the battery

0

RO

3

i-batt-avg

A

float

The average current since the last

measurement (period t_meas (defaults))

0

RO

4

i-batt-10s-avg

A

float

The 10s rollling average current, updated each 1s with T_meas 1000 (ms)

0

RO

5

s-out

-

bool

This is true if the output power is enabled

0

RO

6

s-in-flight

-

bool

This is true if the system is in flight (with flight-mode-enable and i-flight-mode)

0

RO

7

p-avg

W

float

Average power consumption over the last

10 seconds

0

RO

8

e-used

Wh

float

Power consumption since device boot

0

RO

9

a-rem

Ah

float

Remaining capacity in the battery

0

RW

10

a-full

Ah

float

Full charge capacity, predicted battery capacity when it is fully charged. Falls with aging

4.6

RW

11

t-full

h

float

Charging is expected to complete in this

time; zero if not charging

0

RO

12

s-flags

-

uint8_t

This contains the status flags as

described in BMS_status_flags_t

255

RO

13

s-health

%

uint8_t

Health of the battery in percentage, use

STATE_OF_HEALTH_UNKNOWN = 127

if cannot be estimated

127

RO

14

s-charge

%

uint8_t

Percentage of the full charge 0, 100

0

RO

15

batt-id

-

uint8_t

Identifies the battery within this vehicle,

0 - primary battery.

0

RW

16

model-id

-

uint64_t

Model id, set to 0 if not applicable

0

RW

17

model-name

-

char[32]

Battery model name, model name is a

human-readable string that normally

should include the vendor name, model

name and chemistry

"BMS

test"

RW

18

v-cell1

V

float

The voltage of cell 1

0

RO

19

v-cell2

V

float

The voltage of cell 2

0

RO

20

v-cell3

V

float

The voltage of cell 3

0

RO

21

v-cell4

V

float

The voltage of cell 4

0

RO

22

v-cell5

V

float

The voltage of cell 5

0

RO

23

v-cell6

V

float

The voltage of cell 6

0

RO

24

c-afe

C

float

The temperature of the analog front end

0

RO

25

c-t

C

float

The temperature of the transistor

0

RO

26

c-r

C

float

The temperature of the sense resistor

0

RO

27

n-charges

-

uint16_t

The number of charges done

0

RW

28

n-charges-full

-

uint16_t

The number of complete charges

0

RW

29

Parameter

Unit

Datatype

Description

Default

RO/RW

No

n-cells

-

uint8_t

Number of cells used in the BMS board

3

RW

30

t-meas

ms

uint16_t

Cycle of the battery to perform a complete battery measurement and SOC estimation can only be 10000 or a whole division of 10000 (For example: 5000, 1000, 500)

1000

RW

31

t-ftti

ms

uint16_t

Cycle of the battery to perform diagnostics (Fault Tolerant Time Interval)

1000

RW

32

t-cyclic

s

uint8_t

Wake up cyclic timing of the AFE (after front end) during sleep mode

1

RW

33

i-sleep-oc

mA

uint8_t

Overcurrent threshold detection in sleep mode that will wake up the BMS and also the threshold to detect the battery is not in use

30

RW

34

v-cell-ov

V

float

Battery maximum allowed voltage for one cell. Exceeding this voltage, the BMS will go to fault mode

4.2

RW

35

v-cell-uv

V

float

Battery minimum allowed voltage for one cell. Going below this voltage, the BMS will go to fault mode (followed by deepsleep after t-fault-timeout)

3

RW

36

v-cell-nominal

V

float

Battery nominal voltage for one cell. will be used for energy calculation

3.7

RW

37

c-cell-ot

C

float

Over temperature threshold for the cells. Going over this threshold and the BMS will go to FAULT mode

45

RW

38

c-cell-ot-charge

C

float

Over temperature threshold for the cells during charging. Going over this threshold and the BMS will go to FAULT mode

40

RW

39

c-cell-ut

C

float

Under temperature threshold for the cells. Going under this threshold and the BMS will go to FAULT mode

(-20)

RW

40

c-cell-ut-charge

C

float

Under temperature threshold for the cells during charging. Going under this threshold during charging and the BMS will go to FAULT mode

0

RW

41

a-factory

Ah

float

Battery capacity stated by the factory

4.6

RW

42

t-bms-timeout

s

uint16_t

Timeout for the BMS to go to SLEEP mode when the battery is not used.

600

RW

43

t-fault-timeout

s

uint16_t

After this timeout, with an undervoltage fault the battery will go to DEEPSLEEP mode to preserve power. 0 sec is disabled.

60

RW

44

t-sleep-timeout

h

uint8_t

When the BMS is in sleep mode for this period it will go to the self-discharge mode, 0 if disabled

24

RW

45

t-charge-detect

s

uint8_t

During NORMAL mode, if the battery current is positive for more than this time, then the BMS will go to CHARGE mode

1

RW

46

t-cb-delay

s

uint8_t

Time for the cell balancing function to start after entering the CHARGE mode

120

RW

47

t-charge-relax

s

uint16_t

Relaxation time after the charge is complete before going to another charge round.

300

RW

48

i-charge-full

mA

uint16_t

Current threshold to detect end of charge sequence

50

RW

49

i-system

mA

uint8_t

Current of the BMS board itself, this is measured (as well) during charging, so this needs to be subtracted

40

RW

50

i-charge-max

A

float

Maximum current threshold to open the switch during charging

9.2

RW

51

i-charge-nominal

A

float

Nominal charge current (informative only)

4.6

RW

52

i-out-max

A

float

Maximum current threshold to open the switch during normal operation, if not overruled

60

RW

53

i-peak-max

A

float

Maximum peak current threshold to open the switch during normal operation, can't be overruled

200

RW

54

i-out-nominal

A

float

Nominal discharge current (informative only)

60

RW

55

i-flight-mode

A

float

Current threshold to not disable the power in flight mode

5

RW

56

v-cell-margin

mV

uint8_t

Cell voltage charge margin to decide or not to go through another topping charge cycle

50

RW

57

v-recharge-margin

mV

uint16_t

Cell voltage charge complete margin to decide or not to do a battery re-charge, to keep the cell voltages at max this much difference with the cell-ov

200

RW

58

t-ocv-cyclic0

s

int32_t

OCV measurement cyclic timer start (timer is increase by 50% at each cycle)

300

RW

59

t-ocv-cyclic1

s

int32_t

OCV measurement cyclic timer final value (limit)

86400

RW

60

c-pcb-ut

C

float

PCB Ambient temperature under temperature threshold

-20

RW

61

c-pcb-ot

C

float

PCB Ambient temperature over temperature threshold

45

RW

62

v-storage

V

float

The voltage what is specified as storage voltage for a cell

3.8

RW

63

ocv-slope

mV/A.min

float

The slope of the OCV curve. This will be used to calculate the balance time

5.3

RW

64

batt-eol

%

uint8_t

Percentage at which the battery is end-of-life and shouldn’t be used anymore Typically between 90%-50%

80

RW

65

battery-type

-

uint8_t

The type of battery attached to it. 0 = LiPo, 1 = LiFePo4, 2 = LiFeYPo4. Could be extended. Will change OV, UV, v-storage, OCV/SoC table if changed runtime

0

RW

66

sensor-enable

-

bool

This variable is used to enable or disable the battery temperature sensor, 0 is disabled, 1 is enabled

0

RW

67

self-discharge-enable

-

bool

This variable is used to enable or disable the SELF_DISCHARGE state, 0 is disabled, 1 is enabled

1

RW

68

flight-mode-enable

-

bool

This variable is used to enable or disable flight mode, is used together with i-flight-mode

0

RW

69

emergency-button-enable

-

bool

This variable is used to enable or disable the emergency button on PTE8

0

RW

70

smbus-enable

-

bool

This variable is used to enable or disable the SMBus update

0

RW

71

uavcan_node_static_id*

-

uint8_t

This is the node ID of the UAVCAN message

255

RW

72

uavcan-es-sub-id*

-

uint16_t

This is the subject ID of the energy source UAVCAN message (1...100Hz)

4096

RW

73

uavcan-bs-sub-id*

-

uint16_t

This is the subject ID of the battery status UAVCAN message (1Hz)

4097

RW

74

uavcan-bp-sub-id*

-

uint16_t

This is the subject ID of the battery parameters UAVCAN message (0.2Hz)

4098

RW

75

uavcan-legacy-bi-sub-id*

-

uint16_t

This is the subject ID of the battery info legacy UAVCAN message (0.2 ~ 1Hz)

65535

RW

76

uavcan-fd-mode*

-

uint8_t

If true CANFD is used, otherwise classic CAN is used

0

RW

77

uavcan-bitrate*

bit/s

int32_t

The bitrate of classical can or CAN FD arbitration bitrate

1000000

RW

78

uavcan-fd-bitrate*

bit/s

int32_t

The bitrate of CAN FD data bitrate

4000000

RW

79

Parameter

Unit

Datatype

Description

Default

RO/RW

No

v-min

V

uint8_t

Minimum stack voltage for the BMS board to be fully functional

6

RW

80

v-max

V

uint8_t

Maximum stack voltage allowed by the BMS board

26

RW

81

i-range-max

A

uint16_t

Maximum current that can be measured by the BMS board

300

RW

82

i-max

A

uint8_t

Maximum DC current allowed in the BMS board (limited by power dissipation in the MOSFETs)

60

RW

83

i-short

A

uint16_t

short circuit current threshold (typical: 550A, min: 500A, max: 600A)

500

RW

84

t-short

us

uint8_t

Blanking time for the short circuit detection

20

RW

85

i-bal

mA

uint8_t

Cell balancing current under 4.2V with cell balancing resistors of 82 ohms

50

RW

86

m-mass

kg

float

The total mass of the (smart) battery

0

RW

87