Tool/software:
Hi
we've observe the same phenomenon as others have when testing with artificial lighting: the progressive illumination of a solar panel means that the BQ25798 never switches to charge mode.
So, when the sun rises, the solar panel voltage rises slowly and the BQ25798 never switches to charge mode.
Here are the register values when the BQ25798 is blocked, with poor source detection mode enabled:
V_solarPanel = 19.74 V
I_solarPanel = 0.034 A
VBat = 4.60 V
IBat = -0.040 A
VAC1 = 19.65 V
VAC2 = 19.71 V
VSYS = 4.56 V
TDIE = 32.50 degC
MPPT disabled.
REG00_Minimal_System_Voltage = 0x1A (6500 mV)
REG01_Charge_Voltage_Limit = 0x0438
REG03_Charge_Current_Limit = 0x012C
REG05_Input_Voltage_Limit = 0x24 (3600 mV)
REG06_Input_Current_Limit = 0x00AA
REG08_Precharge_Control = 0xCF
REG09_Termination_Control = 0x05
REG0A_Recharge_Control = 0xA3
REG0B_VOTG_regulation = 0x00DC
REG0D_IOTG_regulation = 0x4B
REG0E_Timer_Control = 0x3D
REG0F_Charger_Control_0 = 0xA6
REG10_Charger_Control_1 = 0x00
REG11_Charger_Control_2 = 0x40
REG12_Charger_Control_3 = 0x00
REG13_Charger_Control_4 = 0x21
REG14_Charger_Control_5 = 0x3E
REG15_MPPT_Control = 0xAA
REG16_Temperature_Control = 0xC0
REG17_NTC_Control_0 = 0x7A
REG18_NTC_Control_1 = 0x54
REG19_ICO_Current_Limit = 0x0032
REG1B_Charger_Status_0 = 0x07
REG1C_Charger_Status_1 = 0x0A
REG1D_Charger_Status_2 = 0x01
REG1E_Charger_Status_3 = 0x00
REG1F_Charger_Status_4 = 0x00
REG20_FAULT_Status_0 = 0x00
REG21_FAULT_Status_1 = 0x00
REG22_Charger_Flag_0 = 0x98
REG23_Charger_Flag_1 = 0x90
REG24_Charger_Flag_2 = 0x50
REG25_Charger_Flag_3 = 0x10
REG26_FAULT_Flag_0 = 0x00
REG27_FAULT_Flag_1 = 0x00
REG2E_ADC_Control = 0xB0
REG2F_ADC_Function_Disable_0 = 0x00
REG30_ADC_Function_Disable_1 = 0x00
and when the solar panel is rapidly exposed :
V_solarPanel = 18.86 V
I_solarPanel = 0.631 A
VBat = 9.90 V
IBat = 0.764 A
VAC1 = 18.81 V
VAC2 = 18.79 V
VSYS = 9.90 V
TDIE = 57.00 degC
MPPT enabled.
REG00_Minimal_System_Voltage = 0x1A (6500 mV)
REG01_Charge_Voltage_Limit = 0x0438
REG03_Charge_Current_Limit = 0x012C
REG05_Input_Voltage_Limit = 0xBA (18600 mV)
REG06_Input_Current_Limit = 0x00AA
REG08_Precharge_Control = 0xCF
REG09_Termination_Control = 0x05
REG0A_Recharge_Control = 0xA3
REG0B_VOTG_regulation = 0x00DC
REG0D_IOTG_regulation = 0x4B
REG0E_Timer_Control = 0x3D
REG0F_Charger_Control_0 = 0xA2
REG10_Charger_Control_1 = 0x00
REG11_Charger_Control_2 = 0x40
REG12_Charger_Control_3 = 0x00
REG13_Charger_Control_4 = 0x21
REG14_Charger_Control_5 = 0x3E
REG15_MPPT_Control = 0xAB
REG16_Temperature_Control = 0xC0
REG17_NTC_Control_0 = 0x7A
REG18_NTC_Control_1 = 0x54
REG19_ICO_Current_Limit = 0x00AA
REG1B_Charger_Status_0 = 0x0F
REG1C_Charger_Status_1 = 0x6A
REG1D_Charger_Status_2 = 0x01
REG1E_Charger_Status_3 = 0x00
REG1F_Charger_Status_4 = 0x00
REG20_FAULT_Status_0 = 0x00
REG21_FAULT_Status_1 = 0x00
REG22_Charger_Flag_0 = 0x80
REG23_Charger_Flag_1 = 0x80
REG24_Charger_Flag_2 = 0x00
REG25_Charger_Flag_3 = 0x00
REG26_FAULT_Flag_0 = 0x00
REG27_FAULT_Flag_1 = 0x00
REG2E_ADC_Control = 0xB0
REG2F_ADC_Function_Disable_0 = 0x00
REG30_ADC_Function_Disable_1 = 0x00
+OK
I_solarPanel = 0.631 A
VBat = 9.90 V
IBat = 0.764 A
VAC1 = 18.81 V
VAC2 = 18.79 V
VSYS = 9.90 V
TDIE = 57.00 degC
MPPT enabled.
REG00_Minimal_System_Voltage = 0x1A (6500 mV)
REG01_Charge_Voltage_Limit = 0x0438
REG03_Charge_Current_Limit = 0x012C
REG05_Input_Voltage_Limit = 0xBA (18600 mV)
REG06_Input_Current_Limit = 0x00AA
REG08_Precharge_Control = 0xCF
REG09_Termination_Control = 0x05
REG0A_Recharge_Control = 0xA3
REG0B_VOTG_regulation = 0x00DC
REG0D_IOTG_regulation = 0x4B
REG0E_Timer_Control = 0x3D
REG0F_Charger_Control_0 = 0xA2
REG10_Charger_Control_1 = 0x00
REG11_Charger_Control_2 = 0x40
REG12_Charger_Control_3 = 0x00
REG13_Charger_Control_4 = 0x21
REG14_Charger_Control_5 = 0x3E
REG15_MPPT_Control = 0xAB
REG16_Temperature_Control = 0xC0
REG17_NTC_Control_0 = 0x7A
REG18_NTC_Control_1 = 0x54
REG19_ICO_Current_Limit = 0x00AA
REG1B_Charger_Status_0 = 0x0F
REG1C_Charger_Status_1 = 0x6A
REG1D_Charger_Status_2 = 0x01
REG1E_Charger_Status_3 = 0x00
REG1F_Charger_Status_4 = 0x00
REG20_FAULT_Status_0 = 0x00
REG21_FAULT_Status_1 = 0x00
REG22_Charger_Flag_0 = 0x80
REG23_Charger_Flag_1 = 0x80
REG24_Charger_Flag_2 = 0x00
REG25_Charger_Flag_3 = 0x00
REG26_FAULT_Flag_0 = 0x00
REG27_FAULT_Flag_1 = 0x00
REG2E_ADC_Control = 0xB0
REG2F_ADC_Function_Disable_0 = 0x00
REG30_ADC_Function_Disable_1 = 0x00
+OK
Is there any way to modify this behavior, which renders the BQ25798 unusable with a solar panel?
Thank you very much !
