BQ27426: Average current

user4369354

Part Number: BQ27426

Dear TI support members,

The reading values of AverageCurrent () 0x10 and 0x11 during charging and discharging are different from the measured data as below table.
Is there anything that can be considered as the cause?

	AverageCurrent() 0x10 and 0x11		Voltage of Sense Resistor (0.01Ω)	Current at current probe
	AverageCurrent() 0x10 and 0x11
	HEX	DEC
	-	(mA)	(mV)	(mA)
Charge	359	857	5.990	610
Discharge	ffd3	45	0.338	33

Regards,

Chiaki Endo

over 6 years ago

0 Onyx Ahiakwo over 6 years ago

TI__Guru* 76230 points

hi Chiaki,
did you perform current calibration as listed in the EVM user guide?
thanks
Onyx

0 user4369354 over 6 years ago in reply to Onyx Ahiakwo

Expert 1220 points

Hi Onyx

Thank you for your answer.
I don't understand how to calibrate.
Where is the specific method for calibrating with the product not with the EVM?

Regards,
Chiaki Endo

0 Onyx Ahiakwo over 6 years ago in reply to user4369354

TI__Guru* 76230 points

www.ti.com/.../slua640

0 Shunsuke Nagata over 6 years ago in reply to Onyx Ahiakwo

TI__Genius 13110 points

Onyx -san,

Could you please let me know about below for this phenomenon?

1. As Chiaki -san explained, bq27426 value and measured value at sense register has large gap.
Charge : 857mA (bq27426) VS. 610mA ( measured value)
Discharge : 45mA (bq27426) VS. 33mA (measuerd value)
Will the gap be disapper if he run calibration? He afraid there is other facter for the gap because the gap is so large.
Could you pleae give your advice?

2. bq27426 isn't listed in the slua640 and Datasheet and TRM doesn't explain Host require Calibration.
Is the host calibaration required for bq27426,too?

Regards,
Nagata.

0 Onyx Ahiakwo over 6 years ago in reply to Shunsuke Nagata

TI__Guru* 76230 points

Hi Nagata,
The calibration should improve the measurement accuracy of the gauge. His board may have offsets that calibration would eliminate or atleast reduce.
2. Even though the device is not listed in the app note, the process and methods are applicale,

thanks
Onyx

Power management

Power management forum

BQ27426: Average current