I am really amazed by the knowledge of this community on building efoils. I am just getting into the hobby by experimenting with small motor setups on my paddleboard. However I am running into ESC issues that I can’t figure out. I hope someone here is able to give me some guidance.
I have the setup as shown in the photo. A sequre 120A blheli ESC rated upto 8S. A 6S2P LiPo with molicel p28A, a 40A BMS with transient current of 80A. A 660Kv motor with a small 80mm propeller.
I am testing it at just 30A of current and the ESC gets over 100 degree Celsius in just 20 seconds. If I run it any longer, the solder on the cables melts. The room temperature is around 25 degree Celsius
I also tested another 80A AM32 ESC and it overheats at 20A.
I have the battery cables as short as possible. Both ESCs have capacitors. This sequre ESC has two capacitors. I first measured the current with a watt meter and then removed the watt meter to make sure that the longer cables of watt meter were not the issue. In the past I have used other ESC and motor combinations where running the ESC at half the capacity didn’t overheat them as much.
What motor? Size and pitch of the prop? That prop coulde be too big for this esc. Either try a smaller prop or one with less pitch or get a beefier esc, preferably a vesc or one you can limit the phase current (and the battery current to protect your 2p battery). A paddelboard is hard for the esc, much more resistance than an efoil (constant takeoff mode ). Cooling the esc with a heatsink or watercooling could also help.
I am using surpass hobby BAT3220 motor with a 80mm propeller. Not sure about the pitch.
I am using a heat sink but it doesn’t help.
I tested a different motor and propeller (80mm but different geometry) combo and found that the esc heats up a lot less even if I am drawing the same amount of current. For the 1st motor, I could see the capacitor wire glowing red hot at the same current but for 2nd motor capacitor also doesn’t heat up as much.
After doing lot of research, on different forums, I came to know that if I use a motor that is capable of drawing large current, then even if I operate it at partial throttle, it will heat up the ESC much more than running a different motor at full throttle and the same current draw. I can see that’s what is happening so I either have to get a much larger ESC or downsize the motor to use it at full throttle.
In my opinion investing in a quality esc solves all of the issues above. Many people have luck with specific esc’s on the forum but have to spend lots of time with water cooling, additional heatsinks, or other methods. I have run castle creations esc’s since 2018 and these problems do not exist if you operate within the rating of the esc. I have no involvement with the company, just got tired of chasing problems years ago.
). Cooling the esc with a heatsink or watercooling could also help.