Bat FS firing early

ArduCopter Copter 4.3
1

I’m running 4.3.7 on a Pixhawk1-1M and using Mission PLanner. Must admit it’s been a while. I have a small Eachine quad racer with a 3DR GPS Pwr Module, buzzer and switch.using a 3.3AHr 3S LiPo.

It seems to be going into FS and lands. (usually upside down, I’m still trying to do a more extensive tuning. It’s still kind of sensitive. The screen indicates quite close to the voltage I measure Something like 0.05 difference without load.

Since I was getting these failsafes, I lowered the thresholds to BAT_LOW_VOLT=10.3 and BAT_CRT_VOLT=9.9 I’m reading Bat Voltage w/ no load at 11.76. I get battery failsafe.

I have all current failsafes disabled.

I’ll send the parameter file. I don’t have telemetry or logging enabled.

racerparams.param (15.6 KB)

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I would keep the usual 3S Lipo values and recalibrate the voltage sensor in MissionPlanner.
Probably remove the BATT_CAPACITY value for now.

BATT_ARM_VOLT,11.00
BATT_CRT_VOLT,10.50
BATT_LOW_VOLT,10.80
MOT_BAT_VOLT_MAX,12.60
MOT_BAT_VOLT_MIN,9.90

Calibrate the voltage sensor at a low voltage, like connect a 2S battery for the purposes of calibration (not flying) or use a power supply to provide about 9 volts. Accurately measure the battery voltage with a digital multimeter and set it in MissionPlanner as per below:
https://ardupilot.org/copter/docs/common-power-module-configuration-in-mission-planner.html#analog-monitor-calibration

If your current monitoring is accurate, you can change to using the sag-compensated voltage source:
BATT_FS_VOLTSRC,1
which will be more forgiving.

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