Hi everyone,
As you will see in the logs 1 & logs 2 i am uploading. As soon as my current draw hits 80-ish amps the voltage drops to 41V (started at 48-50V) and any more than 100A and it goes down to 36V . have set the fs to 41V. I need help understanding why is there such a huge drop in voltage. I have a 12s 10C 60Ah Setup (4x 10c 30Ah 6s batteries) So this is like 1-2C current draw. which is supposed to be nothing for this battery. for reference i am also uploading another log from last year (21-09-23) with the same battery pack on a different aircraft. With up to 190A of peak draw, while there is voltage drop there as well, its not as severe even with almost twice the current draw as now.
This (current) aircraft weighs 35 kgs give or take 1.5kgs. just FYI.
So, I Also dont think it makes sense to have this current draw. The motor & prop combination i am using should draw atleast 30A/motor to creat about 8.5kgs of thrust. But with the average draw of 85-90A (meaning about 22ish amps/motor) I should be getting a thrust of just 6.5- 7.2 kg ish, which is not enough to even hover the aircraft. Now while this statement points to the PM being wrong (could be but i dont think so), well i am using mauch PL200 sensors (Hall effect) and using the factory calibration values that were given in the box. Supposedly, this sensor is supposed to be highly accurate and good quality. Hence i dont think its the problem but i will still like to another opinion.
Another battery:
Here is another set of logs of the flights i did next day with a different set of battery 4x 6s 15C 16Ah. Has the same issue.
I do have another observation:
If you compare the longer flights between 2024-06-10 16-10-46 & 2024-06-12 18-44-08 logs. You will see that Since on the latter log of the two i am using a lighter battery, It took about 1 minute longer to reach FS than the former log. While FS is hit eventually on both battery. Due to the overall weight of the aircraft being lower (on the 12-06 log) the current draw is lower for hover. Dont know if it has anything to do with anything.
So really, i am not quite understanding what’s the problem here. If anyone can assist here it will be really helpful.
Edit 130624: I did a test with upside down props. I measured the voltage through a voltmeter and perform a simple throttle test. After looking at the logs and the recorded voltmeter data. Its looks like while the resting voltages are same between the PM and the voltmeter. As soon as i raise the throttle. There is a continous 2V difference. i.e. the voltage shown is the voltmeter is 2V higher than that shown in the logs.