Motor cut off problem

EFOIL.builders Electronics (ESC, remote, batteries)
1

Hi everyone,

I have just got my efoil working this year and I love it! I am having an issue that is stumping me though and I thought i’d ask for some help. I am running at 14s 12p battery with a ANT BMS, Flier 400A boat ESC, Maytech remote, and Flier 120KV motor. I can ride about half an hour and then my power cuts abruptly at 47V. I have looked for a low voltage cutoff in my BMS settings and my ESC settings and it all seems to be set as low as possible unless I am missing something. Is it possible that I have my motor timing and PWM wrong and at that lower voltage it causes it to stall? Any help would be appreciated, thanks!

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2

Is it a vesc? Btw, do you have a link for the motor? Never heard of it.
47V is 3,35v per cell, reasonable cutoff. What are your setings in the esc?
Half an hour does seem short, or do you use 18650 batteries?

3

It is an ESC from Flier.
I have used ESC’ from Flier in my jetboards and unfortunately never got them running good (stoped working sometimes all of a sudden).
Did you ask Flier themselves?
From what I remember they always tried to help

4

Assuming you are using lion cells with max V of 4.2 you would start at 58.8V and drop to 47V in 30 minutes. That to me is a lot.

Have you tried removing the duct on the prop to see if it’s better?

Maybe your ESC is heating up to cutoff?

5

The picture will show my ESC settings. I am using 18650 cells (Samsung 30Q) and the link to the motor is below. How low do you guys set your cutoff voltage per cell? I have not tried to contact Flier as I suspected it was my BMS causing the issue. Is there a way to test if it is the BMS or ESC causing the cutoff? I am in the process of removing the duct but have to make a new part since my duct also supports the rear wing. My front wing is home made and probably also introduces extra drag. I would like to make a thinner one eventually. I never though of the possibility of the ESC heating up and causing the hard cutoff but that is very possible since my water cooling has been acting up. I can fix the water cooling issue and test again to see if that helps. My charger will only get me to 55V so I am currently working with at 8V operating range.

Settings
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6

@Nate747

I’m not familiar with the software you are using as I use VESC tools with a VESC where you can set limit values for temp, voltage etc.

I missed this at first glance but this doesn’t seem correct.

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I believe anything below 2.5V will cause permanently damage.

The date format is also pretty weird!

It also says Slow Cut Off which to me would imply that it would first cause it to slow down at some value above the 2.0V NOT abruptly Shut Off

Can you remove the BMS for a session? Of course it should be there for charging but that would be a way to see if it has some kind of cutoff limit.

7

Connect to the BMS via Bluetooth a check the system log. This will show an under voltage cut off.

Maybe a bad group of cells is causing low cut off, which the BMS will auto recover from after a few minutes.

8

500A Current limit seems a bit high haha. Would put it at 200A.
But imho, just get a vesc, 75200 platform preferably.
Much more control, better setup, better data, etc.
Using a vesc is basically the standard rightnow when it comes to building an efoil.

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