So I managed to get a batch 2 kit from somebody that never had time to build theirs. As a disclaimer, I’ve never flown a paramotor before and have just started a course last weekend. I am, however, a EE and work in the RC hobby industry, so the mod’s that I have done will be mostly related to my experience in those fields.
My build has been flown once by my instructor for 8.5 min on 2x Bonka 6s 22000mah which had 10awg leads originally, but I cut them near the heatshrink and soldered 8awg wires in their place. After the flight, the switch and battery leads were just warm with the hottest thing being the two batteries themselves, but not even close to being untouchable.
So far, I only have a few mods, but I hope to have more additions later on.
In the RC world, it is somewhat known that long power leads to the esc increases inductance, which leads to higher voltage spikes on the ESC since the power draw isn’t continuous (PWM). This is the reason why the ESC includes very long motor/phase wires and short power supply wires, as the length on the wires for the motor side isn’t as critical.
Here is a very detailed RC groups thread addressing the issue
To be on the safe side, I added some 470uf, 100V caps to each of the motor power leads near the start of their respective connectors to my power distribution mess. They are somewhat separated from the ESC rather than being close to it for reasons described in the rcgroups thread.
Here is an image showing what I did.
In this image, you can also see a button on the bottom right in a blue 3D printed mount. The button is soldered in series with a 100ohm 30W resistor, and across the 2 contacts of the main switch. This is to address the arcing pointed out by others when initially turning the switch on after not running the machine for a while. The button is pressed until the first esc beep is heard, then I turn on the main switch.
Here are the parts I used
3D printed mount for button attached.
Pre-Charge Button Bracket v0.stl (69.0 KB)
Battery Lead replacement (for originally 10awg leads):
This is pretty straightforward. I cut the battery leads about 3/4" from the battery heatshrink wrap, and replaced them with 8awg wire. The solder joint was covered in liquid electrical tape, followed by actual electrical tape just to try to ensure that the leads never contact each other