BQ25792: Bq25792 Reading wrong cell count 1S instead of 2S.

also i have checked the voltages of other pins Vin is 5.07V , REGN is 5.8V , pmid 0V, TS 3V , why reign is voltage is greater that vin ?

Read VBAT: 8.136
Read Minimal System Voltage: 7.000
Read Charge Voltage Limit: 8.40
Read Cell Count: 2
Read Charge Current Limit: 2.00
Read Input Voltage Limit: 3.6
Read Input Current Limit: 1.31
Read Precharge Voltage Low: 3
Read Precharge Current: 0.120
Read Plugged In Status: No
Read poor source status: Normal
Read Power Good status: Power good
Read VAC2 present : VAC2 present (above present threshold)
Read VAC1 status: = VAC1 present (above present threshold)
Read Charge Status: Fast Charge
Read VBUS Status: 3
Read Battery Present Status: Yes
Latest readings resoldered ic resolved the issue of 2s battery detection, now all the parameters are correct battery is starting charging stat led glowing when CE pin pulled down but battery is not getting charge, power source detection are okay but plugged in staus coming no
showing fast charge aslo but charging is not starting

Hi Gaurav,

Can you reply back with all of the status and fault registers REG0x1B-0x27?  Also, can you enable the ADC (REG0x2E[7]) and reply back with the ADC values (REG0x31-0x41))?

Regards,

Jeff

HI Gaurav,

The charger is reporting VBUS voltage present and in fast charge.  But the ADC currents and die temp being 0 doesn't make sense.  With ADC enabled, TS pin ADC channel enabled and reading continuously, REGN stays up.

Can you look at SW2 using an oscilloscope to confirm that the converter is switching?  There should be a square wave on SW2.

Regards,

Jeff

Yes sure i will do that tomorrow , one more thing i have noticed that their is 4.2V is present across inductor but it should be 5V as of input. does it will affect anything? 

Hi Gaurav,

If there is 4.2V dc across the inductor, then the converter is not switching. The input side of the input should be 5V. The output side is SW2 and should be switching.

Regards,

Jeff

What will be the issue ? I think main issue is the plugged in status ? How to resolve it? Does lowering frequency to 750KHz will resolve the issue? Have you checked the schematic does anything you can suggest thier?  Also kindly check the gerber file for correction if needed for charging current + System current of 2.5A 2S battery pack does 2 layer board will be fine or i need to go for 4 layer board.

I need to add one more point here that the circuit were working before at 1.33A Input limit to get the charging current upto 2A i have increased the current first 1.6A works fine after increasing current to 2.2A circuit worked for 4 to 5min and turned off after debugging i have found that regn pin were short to gnd then i changed the ic then that 1s instead of 2s issue occurred and now charging not starting issue may be something in the hardware or layouting going wrong please check and give your valuable feedback . 
Bq25792.zip
Total Register Read

Hi Gurav,

I do not see any obvious errors with the schematic above; however, the schematic in the zip has BATP unconnected which could result in the issues you are seeing. Is BATP connected to BAT through a resistor? Can you confirm that /CE =GND and ILIM_HIZ pin is NOT at GND?  The registers look correct.  The gerber shows that you did not follow the recommend board layout, specifically the two 0.1uF caps from PMID to GND and SYS to GND were not placed on top of the IC.  This should not prevent the charger from switching but can result in reduced charge current.

Regards,

Jeff

Hi jeff F,
Yes Batp is connected to bat through resistor of 100R and CE is connected to GND IC turning stat LED ON after CE connected to GND and voltage measured at ILIM_HIZ pin is 2V. About capacitor of PMID and SYS my 2layer pcb limited me to do that.

Okay , I will check that tommarrow and confirm. 

please reply

Hi jeff F thank you for your reply,
I really like to know that and please correct me if i am wrong ,
1) The CC1 and CC2 pins are required for pd voltage negotiation to 9V / 12V right now it is 5V because i have connected 5.1K to gnd from both the pins. 
2) If yes for question 1 then how can i archive 9V input selection for my bq25792 board or it requires separate pd ic? suppose i am able to select 9V input then what will be my max input current limit ? 
3) What are the ic we can use for then please suggest smaller package and will not take much space. 

Jeff F
Sorry to say this but i really want compact ic around 8pin package and will have smaller component count . Do you think ch224k ic will work or any other ic will support?  If TI has this type of ic please suggest.