JK-BMS driver crashes if no Manufacturing Date is given

[MuellerM1996]

Describe the bug

My JK BMS has an empty Manufacturing Date (see screenshot). Since Driver version v1.0.20230531 this gets read from the BMS but the BMS just return 0xFF which can't be interpret.

Error from the log:
2023-09-26 17:27:23.208204500 INFO:SerialBattery:Testing Jkbms
2023-09-26 17:27:23.325547500 ERROR:SerialBattery:Unexpected err=UnicodeDecodeError('utf-8', b'\xff\xff\xff\xff', 0, 1, 'invalid start byte'), type(err)=<class 'UnicodeDecodeError'>

After some experimenting with old commits I found out that the missing Manufacturing Date lead to this error. I comment this out in the jkbms.py line 174 to 178 (on version v1.0.20230531) and everything works as expected.

How to reproduce

Only possible if you have a JK BMS without Manufacturing Date written to the End of Line data. If you connect this you will get the error descript in the log.

Expected behavior

In case the Manufacturing Date is not available, ignore it (leave it on None)

Driver version

v1.0.20230531

Venus OS device type

Raspberry Pi

Venus OS version

3.10

BMS type

JKBMS / Heltec BMS

Cell count

16

Connection type

Serial USB adapter to RS485

Config file

[DEFAULT]

; --------- Battery Current limits ---------
MAX_BATTERY_CHARGE_CURRENT    = 200.0
MAX_BATTERY_DISCHARGE_CURRENT = 200.0

; --------- Cell Voltages ---------
; Description: Cell min/max voltages which are used to calculate the min/max battery voltage
; Example: 16 cells * 3.45V/cell = 55.2V max charge voltage. 16 cells * 2.90V = 46.4V min discharge voltage
MIN_CELL_VOLTAGE   = 2.75
; Max voltage can seen as absorption voltage
MAX_CELL_VOLTAGE   = 3.5
FLOAT_CELL_VOLTAGE = 3.4

; --------- BMS disconnect behaviour ---------
; Description: Block charge and discharge when the communication to the BMS is lost. If you are removing the
;              BMS on purpose, then you have to restart the driver/system to reset the block.
; False: Charge and discharge is not blocked on BMS communication loss
; True: Charge and discharge is blocked on BMS communication loss, it's unblocked when connection is established
;       again or the driver/system is restarted
BLOCK_ON_DISCONNECT = False

; --------- Charge mode ---------
; Choose the mode for voltage / current limitations (True / False)
; False is a step mode: This is the default with limitations on hard boundary steps
; True is a linear mode:
;     For CCL and DCL the values between the steps are calculated for smoother values (by WaldemarFech)
;     For CVL max battery voltage is calculated dynamically in order that the max cell voltage is not exceeded
LINEAR_LIMITATION_ENABLE = False

; Specify in seconds how often the linear values should be recalculated
LINEAR_RECALCULATION_EVERY = 60
; Specify in percent when the linear values should be recalculated immediately
; Example: 5 for a immediate change, when the value changes by more than 5%
LINEAR_RECALCULATION_ON_PERC_CHANGE = 5


; --------- Charge Voltage limitation (affecting CVL) ---------
; Description: Limit max charging voltage (MAX_CELL_VOLTAGE * cell count), switch from max voltage to float
;              voltage (FLOAT_CELL_VOLTAGE * cell count) and back
;     False: Max charging voltage is always kept
;     True: Max charging voltage is reduced based on charge mode
;         Step mode: After max voltage is reached for MAX_VOLTAGE_TIME_SEC it switches to float voltage. After
;                    SoC is below SOC_LEVEL_TO_RESET_VOLTAGE_LIMIT it switches back to max voltage.
;         Linear mode: After max voltage is reachend and cell voltage difference is smaller or equal to
;                      CELL_VOLTAGE_DIFF_KEEP_MAX_VOLTAGE_UNTIL it switches to float voltage after 300 (fixed)
;                      additional seconds.
;                      After cell voltage difference is greater or equal to CELL_VOLTAGE_DIFF_TO_RESET_VOLTAGE_LIMIT
;                      OR
;                      SoC is below SOC_LEVEL_TO_RESET_VOLTAGE_LIMIT
;                      it switches back to max voltage.
; Example: The battery reached max voltage of 55.2V and hold it for 900 seconds, the the CVL is switched to
;          float voltage of 53.6V to don't stress the batteries. Allow max voltage of 55.2V again, if SoC is
;          once below 90%
;          OR
;          The battery reached max voltage of 55.2V and the max cell difference is 0.010V, then switch to float
;          voltage of 53.6V after 300 additional seconds to don't stress the batteries. Allow max voltage of
;          55.2V again if max cell difference is above 0.080V or SoC below 90%.
; Charge voltage control management enable (True/False).
CVCM_ENABLE = True

; -- CVL reset based on cell voltage diff (linear mode)
; Specify cell voltage diff where CVL limit is kept until diff is equal or lower
CELL_VOLTAGE_DIFF_KEEP_MAX_VOLTAGE_UNTIL = 0.010
; Specify cell voltage diff where CVL limit is reset to max voltage, if value get above
; the cells are considered as imbalanced, if the cell diff exceeds 5% of the nominal cell voltage
; e.g. 3.2 V * 5 / 100 = 0.160 V
CELL_VOLTAGE_DIFF_TO_RESET_VOLTAGE_LIMIT = 0.050

; -- CVL reset based on SoC option (step mode)
; Specify how long the max voltage should be kept, if reached then switch to float voltage
MAX_VOLTAGE_TIME_SEC = 3600
; Specify SoC where CVL limit is reset to max voltage, if value gets below
SOC_LEVEL_TO_RESET_VOLTAGE_LIMIT = 95


; --------- Cell Voltage Current limitation (affecting CCL/DCL) ---------
; Description: Maximal charge / discharge current will be in-/decreased depending on min and max cell voltages
; Example: 18 cells * 3.55V/cell = 63.9V max charge voltage
;          18 cells * 2.70V/cell = 48.6V min discharge voltage
;          But in reality not all cells reach the same voltage at the same time. The (dis)charge current
;          will be (in-/)decreased, if even ONE SINGLE BATTERY CELL reaches the limits

; Charge current control management referring to cell-voltage enable (True/False).
CCCM_CV_ENABLE = False
; Discharge current control management referring to cell-voltage enable (True/False).
DCCM_CV_ENABLE = False

; Set steps to reduce battery current
; The current will be changed linear between those steps if LINEAR_LIMITATION_ENABLE is set to True
CELL_VOLTAGES_WHILE_CHARGING   = 3.55, 3.50, 3.45, 3.30
MAX_CHARGE_CURRENT_CV_FRACTION =    0, 0.05,  0.5,    1

CELL_VOLTAGES_WHILE_DISCHARGING   = 2.70, 2.80, 2.90, 3.10
MAX_DISCHARGE_CURRENT_CV_FRACTION =    0,  0.1,  0.5,    1


; --------- Temperature limitation (affecting CCL/DCL) ---------
; Description: Maximal charge / discharge current will be in-/decreased depending on temperature
; Example: The temperature limit will be monitored to control the currents. If there are two temperature senors,
;          then the worst case will be calculated and the more secure lower current will be set.
; Charge current control management referring to temperature enable (True/False).
CCCM_T_ENABLE = False
; Charge current control management referring to temperature enable (True/False).
DCCM_T_ENABLE = False

; Set steps to reduce battery current
; The current will be changed linear between those steps if LINEAR_LIMITATION_ENABLE is set to True
TEMPERATURE_LIMITS_WHILE_CHARGING = 0,   2,   5,  10,  15, 20, 35,  40, 55
MAX_CHARGE_CURRENT_T_FRACTION     = 0, 0.1, 0.2, 0.4, 0.8,  1,  1, 0.4,  0

TEMPERATURE_LIMITS_WHILE_DISCHARGING = -20,   0,   5,  10, 15, 45, 55
MAX_DISCHARGE_CURRENT_T_FRACTION     =   0, 0.2, 0.3, 0.4,  1,  1,  0


; --------- SOC limitation (affecting CCL/DCL) ---------
; Description: Maximal charge / discharge current will be increased / decreased depending on State of Charge,
;              see CC_SOC_LIMIT1 etc.
; Example: The SoC limit will be monitored to control the currents.
; Charge current control management enable (True/False).
CCCM_SOC_ENABLE = False
; Discharge current control management enable (True/False).
DCCM_SOC_ENABLE = False

; Charge current soc limits
CC_SOC_LIMIT1 = 98
CC_SOC_LIMIT2 = 95
CC_SOC_LIMIT3 = 91

; Charge current limits
CC_CURRENT_LIMIT1_FRACTION = 0.1
CC_CURRENT_LIMIT2_FRACTION = 0.3
CC_CURRENT_LIMIT3_FRACTION = 0.5

; Discharge current soc limits
DC_SOC_LIMIT1 = 10
DC_SOC_LIMIT2 = 20
DC_SOC_LIMIT3 = 30

; Discharge current limits
DC_CURRENT_LIMIT1_FRACTION = 0.1
DC_CURRENT_LIMIT2_FRACTION = 0.3
DC_CURRENT_LIMIT3_FRACTION = 0.5


; --------- Time-To-Go ---------
; Description: Calculates the time to go shown in the GUI
;              Recalculation is done based on TIME_TO_SOC_RECALCULATE_EVERY
TIME_TO_GO_ENABLE = False


; --------- Additional settings ---------
; Specify only one BMS type to load else leave empty to try to load all available
; -- Available BMS:
; Daly, Ecs, HeltecModbus, HLPdataBMS4S, Jkbms, Lifepower, LltJbd, Renogy, Seplos
; -- Available BMS, but disabled by default:
; https://louisvdw.github.io/dbus-serialbattery/general/install#how-to-enable-a-disabled-bms
; Ant, MNB, Sinowealth
BMS_TYPE = Jkbms

; Publish the config settings to the dbus path "/Info/Config/"
PUBLISH_CONFIG_VALUES = 1

; Select the format of cell data presented on dbus [Valid values 0,1,2,3]
; 0 Do not publish all the cells (only the min/max cell data as used by the default GX)
; 1 Format: /Voltages/Cell (also available for display on Remote Console)
; 2 Format: /Cell/#/Volts
; 3 Both formats 1 and 2
BATTERY_CELL_DATA_FORMAT = 1

; Simulate Midpoint graph (True/False).
MIDPOINT_ENABLE = False


; Battery temperature
; Specify how the battery temperature is assembled
; 0 Get mean of temperature sensor 1 to sensor 4
; 1 Get only temperature from temperature sensor 1
; 2 Get only temperature from temperature sensor 2
; 3 Get only temperature from temperature sensor 3
; 4 Get only temperature from temperature sensor 4
TEMP_BATTERY = 0

; Temperature sensor 1 name
TEMP_1_NAME = Temp 1

; Temperature sensor 2 name
TEMP_2_NAME = Temp 2

; Temperature sensor 2 name
TEMP_3_NAME = Temp 3

; Temperature sensor 2 name
TEMP_4_NAME = Temp 4

; --------- Battery monitor specific settings ---------
; If you are using a SmartShunt or something else as a battery monitor, the battery voltage reported
; from the BMS and SmartShunt could differ. This causes, that the driver never goapplies the float voltage,
; since max voltage is never reached.
; Example:
;     cell count: 16
;     MAX_CELL_VOLTAGE = 3.45
;     max voltage calculated = 16 * 3.45 = 55.20
;     CVL is set to 55.20 and the battery is now charged until the SmartShunt measures 55.20 V. The BMS
;     now measures 55.05 V since there is a voltage drop of 0.15 V. Since the dbus-serialbattery measures
;     55.05 V the max voltage is never reached for the driver and max voltage is kept forever.
;     Set VOLTAGE_DROP to 0.15
VOLTAGE_DROP = 0.00

Relevant log output

2023-09-26 17:27:23.208204500 INFO:SerialBattery:Testing Jkbms
2023-09-26 17:27:23.325547500 ERROR:SerialBattery:Unexpected err=UnicodeDecodeError('utf-8', b'\xff\xff\xff\xff', 0, 1, 'invalid start byte'), type(err)=<class 'UnicodeDecodeError'>

Any other information that may be helpful

No response

[mr-manuel]

Thanks, I will fix this is the next days

[mr-manuel]

Could you please test https://github.com/mr-manuel/venus-os_dbus-serialbattery/releases/tag/v1.0.20230927beta?

[MuellerM1996]

root@raspberrypi2:~# tail -F /data/log/dbus-serialbattery.ttyUSB5/current | tai64nlocal 2023-09-27 08:35:12.921423500 INFO:SerialBattery:-- Testing BMS: 1 of 3 rounds
2023-09-27 08:35:12.921846500 INFO:SerialBattery:Testing Jkbms
2023-09-27 08:35:13.042058500 ERROR:SerialBattery:Unexpected err=UnicodeDecodeError('utf-8', b'\xff\xff\xff\xff', 0, 1, 'invalid start byte'), type(err)=<class 'UnicodeDecodeError'>
2023-09-27 08:35:13.543388500 INFO:SerialBattery:-- Testing BMS: 2 of 3 rounds
2023-09-27 08:35:13.543821500 INFO:SerialBattery:Testing Jkbms
2023-09-27 08:35:13.594388500 ERROR:SerialBattery:Unexpected err=UnicodeDecodeError('utf-8', b'\xff\xff\xff\xff', 0, 1, 'invalid start byte'), type(err)=<class 'UnicodeDecodeError'>
2023-09-27 08:35:14.095854500 INFO:SerialBattery:-- Testing BMS: 3 of 3 rounds
2023-09-27 08:35:14.096441500 INFO:SerialBattery:Testing Jkbms
2023-09-27 08:35:14.145442500 ERROR:SerialBattery:Unexpected err=UnicodeDecodeError('utf-8', b'\xff\xff\xff\xff', 0, 1, 'invalid start byte'), type(err)=<class 'UnicodeDecodeError'>
2023-09-27 08:35:14.646753500 ERROR:SerialBattery:ERROR >>> No battery connection at /dev/ttyUSB5

Still the same error.

But if I change the except UnicodeEncodeError to a except UnicodeDecodeError it's working.

[mr-manuel]

Damn. I rebuild it with the correct exception :-)