MAX17055 Operating Current

The voltage fuelgauge could be influencing the reported SOC, so this may not be the best method of measuring the accumulated current.  To view the raw coulomb count, you can look at the QH register (Register address 0x4Dh) and see how it is changing over time.  The QH register has the same LSB as the other capacity registers.

Dear Jcole97

Using DS91230+ and MAX17055 and GUI INIT preset parameters
How can the current consumption of the MAX17055 be calculated in the no-load state after the battery is set? Are the functions that consume current enabled in the GUI by default?

Thank You

Frank

The only way to really measure the IQ current consumption is to have an ammeter in series with the battery if that is what you are looking for.  If you are looking for the measured current flowing across the sense resistor,  the QH register will update if there is any actual current measured across the sense resistor.

Dear Jcloe97

Use the monitoring QH register with an ammeter to detect the current consumption. What is the unit of the GUI Dadalog QH value in uA or LSB?

Thank You

Frank

Hi Frank,

The GUI will log the QH in mAH as scaled by the sense resistor.

Thanks,

Jason

Dear Jason 

MAX17055 conducted a 64-hour current consumption test. According to the 0x4DH QH register, the current consumption is close to the estimate of about 4mAH. However, RepSOC shows that the consumption is 16.5mAH, which is *4 times higher than the actual gap.
How does GAS Gauge return the SOC capacity through I2C to correct consumption?

20240712

20240715

Thank You

Frank

Hi Frank,

QH is the raw coulomb counter, so that will show the direct accumulated measured current.  RepCap takes inputs from the voltage fuel gauge, the coulomb counter, the empty compensation, and a few other places.  The delta betwee the screenshots can be attributed to these items.  We see the VFRemCap (Remaining Capacity according to the voltage fuel gauge) drops by ~5mAH.  We can see the Empty Compensation have a slight change of ~7.5mAH, and then also the QH change by ~4mAH.  These are all quiet normal behaviors to let you know there are multiple inputs into the fuel gauge algorithm before getting to the final answer that is displayed in RepCap.

Thanks,
Jason

Dear Jason

In order for Rapcap to provide capacity information to the host, can it convert or read other register settings or places where the hardware can be adjusted? Can Rapcap's capacity consumption be close to the actual current consumption?

PS: What are the required conditions for < 3% ERROR?

Thank You

Frank