Motors consume more current than I expect

Hi guys,

I built the copter using Ardupilot and found that it flights great (after INAV all moves are predictable, no issues with altitude, poshold etc, I really like it now). But I noticed that the copter consumes a little bigger current that I am sure might be enough. I have not a big frame, and for example on INAV it took about 4.5-5.0 amps in hover mode, but Arducopter consumes up to 8.2 amp.

May somebody help me to identify the root cause? I took the screenshot from RCOU fields from the logs,

and it seems that the motors receive extremely pikes from the AP. How can I ‘interpolate’ it and where is the right thing I need to look into?

Thank you.

:slightly_smiling_face: , spikes, motors driven to the maximum, wasn’'t it in autotune?.
Please post a logfile(or bin) , so that some experts can take a look.

I do not think so. The spikes are high-frequency. Here is the log of the flight. First (and bigger) part it the autotune, after that I landed, and took-off again with new pids. The hi-freq spiker were before, during and after the auto tune.

Does anybody know how to find the reason of high current consumption?

did you calibrate your current monitor on both ArduPilot and Inav?

Yes, I did. I might be a little bit wrong, but the difference is too huge so I believe in the current settings the current is overdrawn somehow. BTW it flights well. But these spikes… Do not give me a relief… )

Those spikes dont look big to me - yes they are multiples of the hover current, but they do align with pitch and roll movements. To me that indicates the motors have to work hard to correct roll and pitch and bring the craft back to level.
Maybe let us know what size craft and props you have, plus weight, any other details you can think of.

Assuming you have something like 5inch props or smaller, you could probably increase these:
ATC_ACCEL_P_MAX 165300
ATC_ACCEL_R_MAX 165300
ATC_ACCEL_Y_MAX 31500

I have 8 inch props 3 blades 8045. 8 inch frame. the weight is about 900 g with batery.

I will post the photo later

Ok, your key parameters are reasonably close then, except maybe MOT_THST_EXPO.
Your BATT_CRT_VOLT and BATT_LOW_VOLT are not correct, wrong way around. Check my suggestions for them.

My calcs give me these for 8inch and 4 cells, some are just what I would use as a starting point and not necessarily related to an issue you’re having:

ACRO_YAW_P,3.20
ATC_ACCEL_P_MAX,126900
ATC_ACCEL_R_MAX,126900
ATC_ACCEL_Y_MAX,28800
ATC_RAT_PIT_FILTD,25.50
ATC_RAT_PIT_FILTE,0.00
ATC_RAT_PIT_FILTT,25.50
ATC_RAT_RLL_FILTD,25.50
ATC_RAT_RLL_FILTE,0.00
ATC_RAT_RLL_FILTT,25.50
ATC_RAT_YAW_FILTD,0.00
ATC_RAT_YAW_FILTE,2.00
ATC_RAT_YAW_FILTT,25.50
BATT_ARM_VOLT,14.70
BATT_CRT_VOLT,14.00
BATT_LOW_VOLT,14.40
INS_ACCEL_FILTER,20.00
INS_GYRO_FILTER,51.00
MOT_BAT_CURR_MAX,30.00 <- set this based on your max battery or power distribution current, whichever is lowest
MOT_BAT_VOLT_MAX,16.80
MOT_BAT_VOLT_MIN,13.20
MOT_THST_EXPO,0.62

You can set these since you’ve run Autotune already:
PSC_ACCZ_I,0.36
PSC_ACCZ_P,0.18
ATC_THR_MIX_MAN,0.50

Tried these changes today. Nothing significantly changed. So it seems that the copter really consumes at about 8-8.5 amp for hover. Hm, ok. I will try one more attempt of reducting P and D pids twice or a 4 times to see maybe it will affect. I will keep you informed. Thank you.