Usually brushless motors comes with indications on how many batteries you can connect to them, it is common to to see 2x3 battery packs where each battery provides 3.6 Volts or so to power a single brushless motor. However I fear things are not that simple when putting much more stuff in parallel.
Let's assume I have a battery with
- 9000 mah
- 210 grams weight
- rated 10C
- 3.7 Volts working
- 2.8 Volts discharge cutoff
If I want to operate a brusheless motor at 7.4 volts I have to put 2 batteries in series, then if the operating current for the motor is 10A, with a 15 A ESC connected to it, then the motor will run for about 54 minutes) in theory (in reality it would be less due to infinite factors).
However if I setup 10 brushless motors, each one with 2 batteries, every motor will run at most 54 minutes, but due to motors each running at slightly different powers, some motors will ends power sooner than others, and they will turn soon into extra useless weight for the drone.
If I want to share all the power across all motors to avoid some stuff turning suddendly into dead weight, I have to setup an array of batteries with 2 rows in series, and 10 in parallel (20 total batteries).. Is there any extra precaution to use compared to a regular parallel light bulbs?
The theory behind my question is that if I put motors in parallel and batteries in parallel, I can view motors as resistances, in ideal world each motor would absorb same amount of current, but motors do not have constant resitance, which makes me fear that under some conditions I could actually burn my motors or my batteries by providing much more more power putting so many batteries in parallel.
As long as I burn a single battery or a single motor it is fine, but If doing this is wrong I could actually burn a lot more motors and batteries: lot more money gone. That's why I'm asking to experts.
I have no degree so far in any electric-related stuff, I'm learning everything from internet so I'm sorry If I'm not asking the question in the best possible way.