Motor specs and amp draw

Power System
#1

Is the kit still shipping with mad components M10 180kv motors?

Second question,

Has someone physically hooked up a current meter to confirm the system is pulling 300amps at full power?

Has anyone done a long full power climb with their battery system yet? Long meaning 5-10min?

Chris at VeConcepts is keen to find us a li ion battery solution that is reliable, industrial quality, affordable and that can handle the requirements of this system. Chris mentioned they have a high amp anti spark switch they have designed that would work for this project, it’s rated for up to 16s. They use a 400amp esc so I’m assuming it would work for 300amp.

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#2

I know I would still be interested in a single switch solution – I found one but it is big.

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#3

I am very interested in the VeConcepts battery, and I have been considering designing my own li-ion. I think including the BMS would have its own switch. So the kit switch would only be needed for emergency power kill.

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#4

Chris is comparing notes between the two of us to take to his battery designers. I mentioned the problems we have had with the switch and asked if he has a solution and it sounds like he does. In the development of his eFoil he had to cross a lot of the same bridges as us which is why I wanted to pull him in.

They are also using higher volts with a 16S system. I would love to convert my OpenPPG to 16S. It would require finding good ESCs that aren’t too expensive (specially since we need 4 of them) and getting the motors custom wound to 135 KV. Our Amp draw, which is now 320 according to Paul, would drop to only 240 with 16S. That means the ESCs would only need to handle 60 amps each.

I am going to buy an eFoil from Chris and would actually like to use the same battery and charger for both the eFoil and the OpenPPG. Even if that wasn’t my plan I would still like to see the future of this project go to higher volts. Our current ESCs can handle 14S but even converting to 14S would require new motor windings. Or smaller props which would be less efficient. Any of these changes would require slight changes to the throttle controller as well but Paul sounds willing to support that.

#5

Dave is the only one on this forum that I have ever seen post about measuring current:

Has anyone else actually measured current at full throttle. I believe Dave’s test was a static test.

Chris sent me a link to an amp meter. I’m going to buy one and install it. I like that I won’t have to splice wires to use it because it’s a Hall effect sensor. Just have to run the red wire from one ESC through it.

#6

FYI the voltage divider and BEC for supplying 5v out are designed to work up to 60v so a 14s should be fine in that aspect.

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#7

It helps that Chris is also a pilot and he’s actually interested in getting an openppg for himself now. Sounds very willing to help us out to find a good battery solution. Yes it seems they have been through the hell of testing different batteries, switches etc for high amp draw application. They use a solderless connector for the battery to system as they found this was a weak link in their tests as well.

I would think 13s would be most ideal for this setup, since this is also the voltage for most e scooters it’s easy to find good chargers for this voltage.

X fingers they can build us an affordable, durable/reliable lithium ion battery pack.

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#8

Might as well stick to 12S. If you’re thinking about changing voltage you should change by more than one cell to reap the rewards of lowering amps. 13S would increase the RPMs which would draw more amps unless you also change the motor KV. If you’re going through the trouble to change the motor KV you might as well go enough to make a significant difference or not change it at all. Plus, Chris has a custom built charger as well.

#9

I purchased this amp meter that Chris recommended:

It was supposed to arrive in 3 days yet I received it overnight! That was the free shipping option too!

I opened up my motor and installed it on the red wire going to one ESC:

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My batteries were at 45 volts (storage charge with 50% capacity) and the meter read 75 amps. This was a static test. I expect it to be slightly lower while flying through the air.

That’s 300 amps total!

#10

Which props did you have on with a 75A draw?

#11

22 x 10 propellers at 4,500 feet above sea level.

#12

That’s really helpful to know!
Do you know what your cruise amp draw is?

#13

I just installed it last night and did a static test (standing still) with it. I will report a lot more detail after I fly with it.

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#14

Thanks for your hard work in testing and sharing results! This will help with li ion battery development for this project.

#15

I’m rigging up my current sensor to an Arduino right now and will be doing current, voltage, PWM, etc for the whole flight. Will post results when weather become flyable

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#16

Does anyone know if these motors can handle 14s voltages? It sounds like everything else can in the system. Apparently going from 12s to 14s would reduce the amp draw by 16%.

Looking forward to batch 4 and helping solve some of these issues.

#17

Hey guys!
I just joined the forum here. I LOVE this product idea and want one for myself!

I will be meeting with our battery engineer and going over cell options for a 12S system, and if someone can confirm the BEC, ESC, and motors can handle 14S (motors based on manufacture show they are 12S only but I hope I am wrong), if we can do 14S I think that would make for a great solution without the need to change motor KV in my opinion. Maybe the creator of this product has tested 14S already?

14S is a nominal 1300 RPM different, something you would learn and adjust your throttle finger to easily within 1-2 flights. I would be slightly more responsive nothing significant though and in fact, it may feel and be better. It should also lower the AMPS as when volts rise, amps/heat will decrease.

My focus is 100% on my Electric Hydrofoil Surfboard - EFOIL but I want to make a battery and switch solution for this cool OpenPPG product before I buy one for myself later this year. I have dealt with enough Lipo cells that I just simply will not fly with one strapped onto my back that I cannot get off me if flares up.

Has anyone thought of installing thin stainless or aluminum plate behind the battery packs as a firewall of some sort?

So, if I can get detailed stats/specs or the ESC, Motor, and Full throttle AMPS and Average Cruise amps, along with a diagram of how the power switch is wired into one battery pack I will see what our engineers come up with for the battery and high current switch.

What AH size packs are people thinking? 35, 40, 45, 50Ah?

Also, what switches have been used here that have been failing so we can review what does not work as that is half the learning curve, knowing what does not work well.

Cheers!
Chris V.

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#18

Thanks for joining the project, looking forward to your input. The ESC and motor can both handle 14s. The BEC and voltage sensing PCB we designed for 14s (up to 60v). As for a firewall, the two plates of CF are very good firewalls in my opinion, there was a question in the forum earlier about it. A few people have made metal battery boxes if you look around.

The ESC are 80a 4-14s, the max current is 320a ±10. I think a 45Ah battery would be best.

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#19

Thanks Pdwhite!
What is the sensing PCB? is this part of the BEC meaning if I can get a 14S BEC all would be good or is the sensing PCB separate?

What minimum volts is required for the sensing PCB? can the BEC power it?

The only reason I mentioned metal firewall is that I don’t like the idea of holes for heat/battery fire to get through if there ever was a flare-up. I actually have custom fireproof battery bags for all our batteries. This would actually work well in flight because its light and will ack as another firewall. Could cause the battery to get a little warmer if under full throttle for while but nothing significant.

Anyways, Ill look into 12S custom high current and 14S and see what we come up with.

Any insight on power switches?

#20

Nice to have you on board with us Chris! Your experience and solutions will be valuable to us for both reliability and safety.

Here is a thread that talks about the PCB: