Any way to set current sensor offset as well as multiplier?

In Betaflight they allow adjusting both offset and multiplier when calibrating the current sensor. In ArduPlane I only see a way to adjust the multiplier. Is the offset deemed not necessary to adjust?

I’m also wondering about this. If I follow Ardupilot’s official method for calibrating using the current sensor’s total current, the monitored current becomes inaccurate. On the other hand, if I set the monitored current accurately, the total current becomes inaccurate.

They are both there in the parameters arent they? Dont use the wizard on the hardware page, use the parameters

What do you mean monitored current and total current? Are you talking about current measured through a power module?

total current = current measured by charger

monitored current = current display at mission planner during flight. current current.

They are both there in the parameters arent they? Dont use the wizard on the hardware page, use the parameters

← I’m using parameters already.

Current measured by charger? Are you using a charger to calibrate? Im not exactly with you.

Basically you want the mission planner measured current to match the battery current (the current flowing through the leads to the battery plug) this is what is through the shunt resistor and should total the esc input current and any current used by the power module for regulated dc supplies.

Current measured by charger? Are you using a charger to calibrate? Im not exactly with you.

Basically you want the mission planner measured current to match the battery current (the current flowing through the leads to the battery plug) this is what is through the shunt resistor and should total the esc input current and any current used by the power module for regulated dc supplies.

← have you read ardupilot official document and recommendation for battery calibration here?

or have you calibrated power monitor?

“”"
Calibration of the BATT_AMP_PERVLT value can either be done on the bench with a current meter, or iteratively by estimating an initial value, operating for while, measuring the amount of current needed to restore the battery to full charge, and using that value and a flight log’s or OSD’s total consumed mah for the flight to adjust the parameter value:

new value = old value * (mah returned to batt/log or OSD value of consumed mah)
“”"

[1]
https://ardupilot.org/copter/docs/common-synthetic-current-monitor.html

[2]

Okay, looks like BATT_AMP_OFFSET is what I’m looking for…I was confused because it’s not shown in the Mission Planner “Battery Monitor” page and the calibration page doesn’t mention it.

Ideally a current sensor calibration would involve several measurements at different power levels to derive the BATT_AMP_OFFSET and BATT_AMP_PERVLT values.

Yes battery amp offset is the zeroing parameter and the amp/volt is the span.
Its just a linear function so you would ideally need just two points that are far apart if possible ( i use like 1 and 10A because thats what my multimeter limit is)
The idea of using the battery chargers integrator to tell you the charge mah and adjusting for that figure seems like only a ‘next best’ solution as it would include balancing current, some losses in charging heat etc. There is also the problem of non linearity of the shunt based current measured at low ranges and no doubt some variation of shunt resistance with temperature change during high current consumption so its not an exact science.

“total current consumed by flight” becomes very inaccurate when I set “the current should be displayed on mission planner screen at current flight” accurately.

with many copter I built.

its not problem of “balancing current, some losses in charging heat etc.”

do you get exact this two value with your copter?

If you are referencing your charger total mAh charged then you are now also relying on the charger accuracy too have you tested this against another meter to confirm?

so do you get exact two value(current current value, total consumed current value) with your arducopter?

with your exact current meter?

I didn’t mean to require 1cm accuracy. I don’t need an exact value; a value that is similar is sufficient. However, there are currently many errors in the provided value. For instance, it is off by two times from the actual current value.

with new power module and new copter it is same.

you can review my previous topic.

there are huge difference between two power modules