BQ76942: Cell 8 and 9 on top of battery pack balance much slowly

void BQ769x2_Init() {

CommandSubcommands(BQ769x2_RESET); // Resets the BQ769x2 registers

HAL_Delay(60);

// Configures all parameters in device RAM

// Enter CONFIGUPDATE mode (Subcommand 0x0090) - It is required to be in CONFIG_UPDATE mode to program the device RAM settings

// See TRM for full description of CONFIG_UPDATE mode

CommandSubcommands(SET_CFGUPDATE);

// After entering CONFIG_UPDATE mode, RAM registers can be programmed. When programming RAM, checksum and length must also be

// programmed for the change to take effect. All of the RAM registers are described in detail in the BQ769x2 TRM.

// An easier way to find the descriptions is in the BQStudio Data Memory screen. When you move the mouse over the register name,

// a full description of the register and the bits will pop up on the screen.

// 'Power Config' - 0x9234 = 0x2D80

// Setting the DSLP_LDO bit allows the LDOs to remain active when the device goes into Deep Sleep mode

// Set wake speed bits to 00 for best performance

// This 0x2D80 includes SLEEP_EN, on-chip over temperature, more clear in 136 of TRM

BQ769x2_SetRegister(PowerConfig, 0x2D80, 2);

// 'REG0 Config' - set REG0_EN bit to enable pre-regulator

// Not use LDO supplied by BQ including REG1 and REG2, leave this pin reset state: 0x00, and have to supply external to REG0 Pin

// Use LDO including REG1, REG2, leave this pin set state: 0x01

BQ769x2_SetRegister(REG0Config, 0x01, 1);

// 'REG12 Config' - Enable REG1 with 3.3V output (0x0D for 3.3V, 0x0F for 5V)

// This register reserved for Setting up how much values of REG1 and REG2

BQ769x2_SetRegister(REG12Config, 0x0D, 1);

// Set DFETOFF pin to control BOTH CHG and DSG FET - 0x92FB = 0x42 (set to 0x00 to disable)

BQ769x2_SetRegister(DFETOFFPinConfig, 0x00, 1);

// Set up ALERT Pin - 0x92FC = 0x2A

// This configures the ALERT pin to drive high (REG1 voltage) when enabled.

// The ALERT pin can be used as an interrupt to the MCU when a protection has triggered or new measurements are available

//BQ769x2_SetRegister(ALERTPinConfig, 0x2A, 1);

// Set TS1 to measure Cell Temperature - 0x92FD = 0x07

BQ769x2_SetRegister(TS1Config, 0x07, 1);

// Set TS3 to measure FET Temperature - 0x92FF = 0x0F

//BQ769x2_SetRegister(TS3Config, 0x0F, 1);

// Set HDQ to measure Cell Temperature - 0x9300 = 0x07

BQ769x2_SetRegister(HDQPinConfig, 0x00, 1); // No thermistor installed on EVM HDQ pin, so set to 0x00

// 'VCell Mode' - Enable 16 cells - 0x9304 = 0x0000; Writing 0x0000 sets the default of 16 cells

//BQ769x2_SetRegister(VCellMode, 0x0000, 2);

BQ769x2_SetRegister(VCellMode, 0x01FF, 2); // used 9 cells

// Enable protections in 'Enabled Protections A' 0x9261 = 0xBC

// Enables SCD (short-circuit), OCD1 (over-current in discharge), OCC (over-current in charge),

// COV (over-voltage), CUV (under-voltage)

BQ769x2_SetRegister(EnabledProtectionsA, 0xBC, 1);

// Enable all protections in 'Enabled Protections B' 0x9262 = 0xF7

// Enables OTF (over-temperature FET), OTINT (internal over-temperature), OTD (over-temperature in discharge),

// OTC (over-temperature in charge), UTINT (internal under-temperature), UTD (under-temperature in discharge), UTC (under-temperature in charge)

//BQ769x2_SetRegister(EnabledProtectionsB, 0xF7, 1);

BQ769x2_SetRegister(EnabledProtectionsB, 0xF4, 1);

// 'Default Alarm Mask' - 0x..82 Enables the FullScan and ADScan bits, default value = 0xF800

BQ769x2_SetRegister(DefaultAlarmMask, 0xF886, 2);

// Set up Cell Balancing Configuration - 0x9335 = 0x03 - Automated balancing while in Relax or Charge modes

// Also see "Cell Balancing with BQ769x2 Battery Monitors" document on ti.com

// Balancing in Charging mode, relax mode, and sleep mode

// Cell balancing only in Relax mode

BQ769x2_SetRegister(BalancingConfiguration, 0x02, 1);// 07

// Minimum cell temperature to prevent cell balancing is set to -127 degree

BQ769x2_SetRegister(MinCellTemp, -127, 2);

// Maximum cell temperature to prevent cell balancing is set to 127 degree

BQ769x2_SetRegister(MaxCellTemp, 127, 2);

// Maximum cell internal temperature to prevent cell balancing is set to 127 degree

BQ769x2_SetRegister(MaxInternalTemp, 127, 2);

// Time interval between cell balancing event is 1 s

BQ769x2_SetRegister(CellBalanceInterval, 10, 2);

// Number of cells are balanced in the same time is 2

BQ769x2_SetRegister(CellBalanceMaxCells, 5, 2);

// Maximum voltage threshold of each cell to allow balancing in charging is 2,5 V

BQ769x2_SetRegister(CellBalanceMinCellVCharge, 2500, 2);

// Minimum difference of cells to start balancing is 30 mV in charging mode

BQ769x2_SetRegister(CellBalanceMinDeltaCharge, 10, 2);

// Difference of cells to stop balancing is 20 mV in charging mode

BQ769x2_SetRegister(CellBalanceStopDeltaCharge, 3, 2);

// Maximum voltage threshold of each cell to allow balancing in relax is 2,5 V

BQ769x2_SetRegister(CellBalanceMinCellVRelax, 2500, 2);

// Minimum difference of cells to start balancing is 30 mV in relax mode

BQ769x2_SetRegister(CellBalanceMinDeltaRelax, 15, 2);

// Difference of cells to stop balancing is 20 mV in relax mode

BQ769x2_SetRegister(CellBalanceStopDeltaRelax, 10, 2);

// Charge current threshold: 500 mA, allow BQ know is in Charging

BQ769x2_SetRegister(ChgCurrentThreshold, 200, 2);

// Discharge current threshold: 500 mA, allow BQ know is in Discharging

BQ769x2_SetRegister(DsgCurrentThreshold, 500, 2);

// Set up CUV (under-voltage) Threshold - 0x9275 = 0x31 (2479 mV)

// CUV Threshold is this value multiplied by 50.6mV

BQ769x2_SetRegister(CUVThreshold, 0x31, 1);

// Set up COV (over-voltage) Threshold - 0x9278 = 0x55 (4301 mV)

// Tang gia tri neu dien ap cell pin bi qua ap khong the sac duoc, gia tri hex quy doi sang dec, roi nhan voi 50,6 mV

// COV Threshold is this value multiplied by 50.6mV

BQ769x2_SetRegister(COVThreshold, 0x5E, 1);

// Set up OCC (over-current in charge) Threshold - 0x9280 = 0x05 (10 mV = 10A across 1mOhm sense resistor) Units in 2mV

BQ769x2_SetRegister(OCCThreshold, 0x32, 1);

// Set up OCD1 Threshold - 0x9282 = 0x0A (20 mV = 20A across 1mOhm sense resistor) units of 2mV

BQ769x2_SetRegister(OCD1Threshold, 0x0A, 1);

// Set up SCD Threshold - 0x9286 = 0x05 (100 mV = 100A across 1mOhm sense resistor) 0x05=100mV

BQ769x2_SetRegister(SCDThreshold, 0x05, 1);

// Set up SCD Delay - 0x9287 = 0x03 (30 us) Enabled with a delay of (value - 1) * 15 µs; min value of 1

BQ769x2_SetRegister(SCDDelay, 0x03, 1);

// Set up SCDL Latch Limit to 1 to set SCD recovery only with load removal 0x9295 = 0x01

// If this is not set, then SCD will recover based on time (SCD Recovery Time parameter).

BQ769x2_SetRegister(SCDLLatchLimit, 0x01, 1);

// Exit CONFIGUPDATE mode - Sub-command 0x0092

CommandSubcommands(EXIT_CFGUPDATE);

HAL_Delay(10);

CommandSubcommands(FET_ENABLE); // Enable the CHG and DSG FETs

HAL_Delay(10);

BQ769x2_BOTHOFF();

HAL_Delay(10);

CommandSubcommands(SLEEP_DISABLE); // Sleep mode is enabled by default. For this example, Sleep is disabled to

HAL_Delay(240);

}