This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ35100: Current Resolution

Part Number: BQ35100


Registers 0x0C & 0x0D are the 16-bit signed value for the battery current measured, being the voltage across the (normally) 0.1 ohm sense resistor.
The value has a range of -32,678mA - +32,767mA.

(1) The sense resistor value is normally 0.1 ohms. The maximum voltage across this sense resistor is -/+ 0.125V. Therefore the maximum current measured is -/+ 1.25 A, i.e. -/+ 1250mA.
This is a much smaller range than the -/+ 32,767mA range of the 16-bit signed value. I guess the MSB's are just set to all 1's/all 0's?

(2) If the maximum battery current in use is greater than -/+ 1.25A, a smaller value for the sense resistor is required, e.g. 0.05 ohm for -/+ 2.5A.
If this is done, is there a way to configure the gauge so that it adjusts for this? At present I am using a suitable scale factor in the firmware that drives the gauge.

Simon W.