I’m flying a stock Tarot 650 that has a Pixhawk 4 and orange cube. It arms and flies in loiter mode normally and then suddenly panics about loss of thrust and low voltage even though the battery is fully charged and the logs do not show voltage dipping below the threshold. It also reports failsafe even though they are disabled. What should I look for? Loose wiring?
here is the log:Dropbox - log_19_2023-5-6-14-54-04.bin - Simplify your life
Apologies, this is the log from an earlier flight where things seemed to go normally. I will post the log from a later flight after recharging the battery where these panics occurred much more quickly.
@dkemxr, how did you plot multiple scales? I get everything on the largest scale which compresses the voltage. I’ve tried right- and left-clicking in several places but can’t find the the trick?
Left click left Y-axis, right click right Y-axis. Updat MP to latest Beta if things don’t work.
Exactly what Dave said, but that battery is dead. Even when you took off the battery was too low.
You should use the initial parameter setup in mission planner (since much of the drone is on defaults) and make sure you set up the battery failsafes. Those would have prevented this incident.
Also a good idea to update to the latest firmware since there’s been some updates that are applicable to the orange cube.
Thank you both for your time and analysis.
You are both correct (obviously), the battery was not charged. There was a misunderstanding due to the charger showing 22.2 V as maximum charge for a 6s battery even though it will charge beyond that. After charging to 24.5 V the flights worked flawlessly.
Full charge is 25.2V for LiPO FYI.
Understood. 4.2 x # of cells is the max recommended voltage.
Definitely set these even if you are using capacity (mAh) for battery monitoring.
The capacity monitoring is only good if you always start with a fully recharged battery and never reboot the FC between flights AND nothing ever goes wrong with the battery.
BATT_ARM_VOLT,22.10
BATT_CRT_VOLT,21.00
BATT_LOW_VOLT,21.60
BATT_FS_CRT_ACT,1
BATT_FS_LOW_ACT,2 // or 3
MOT_BAT_VOLT_MAX,25.20
MOT_BAT_VOLT_MIN,19.80
and if they give you any trouble DO NOT change these values → you would check you voltage monitor calibration or the battery is bad.
Thank you for those settings.