Boat ESC - success Only works for me though.

dirkdiggler

10 kW
Joined
Oct 17, 2012
Messages
641
I wired up an HK 90a Boat ESC tonight to see if I could burn it up. Ran surprisingly well. I put about 3 miles on it. Nothing too strenuous, a few hills, but mostly flats at a about 15mph. I stopped every once in a while to check if it was going to light up. It never got hot to the touch. Even without the water cooling system and after the hill climbs. One thing I did really like were the brakes. They were mellower than the car ESC, but the nice thing was no noise. I always hated riding late through the neighborhood because the horrible noise the brakes made. I do wonder if that is something that can be programmed into the firmware like someone posted a while back.
I looked into the HV boat ESCs tonight. Still more expensive than the car version, biggest issue was if they had brakes and some were opto. The thought of having to add another battery - more things to hide - turns me off from that. Might need to figure out how a ubec works. That was another nice thing about the boat ESC - the size. You could glue it to the board if you wanted, much smaller. I have thought of removing the fan on the 150a car ESC and replacing it with some kind of heat sink to get the size down. There were a few interesting fan ideas on ebikes that I liked, having a fan on the end of the motor to cool everything off.
I will try to put some more miles on the boat ESC to see how long it lasts.
 
Wow.. Pretty cool. Let me know more about how the brakes work. I'm definitely interested because that's the only reason why I didn't get a boat ESC. That would allow more of us to go higher voltage without spending an arm and leg. Have you tried the brakes going down hill?
 
I've ridden this ESC all week and have yet to have any issues. Still loving the quiet, mellow braking. I've seen a few people say the car ESC brakes don't make noise, but all of mine have. They would squeal like a pig. Not a grinding noise, but it still isn't pleasant. Will see how much longer the $30 ESC lasts!
 
This is great! There is a $68.27 80A with a 12s capacity. This means we can use a 36v+ Lifepo4 and not worry about the lower amp delivery of the Lifepo4 compared to Lipos. BTW, does it have neutral?
 
dirkdiggler said:
I've ridden this ESC all week and have yet to have any issues. Still loving the quiet, mellow braking. I've seen a few people say the car ESC brakes don't make noise, but all of mine have. They would squeal like a pig. Not a grinding noise, but it still isn't pleasant. Will see how much longer the $30 ESC lasts!

Hows the startup? The problem i had with a plane esc is that it really struggled for sink at low speeds... Also is it just a drag brake or an adjustable one like car escs?
 
This is what I have been using,thinking it would blow after a few runs (only $30):
28223.jpg
http://www.hobbyking.com/hobbyking/store/__28223__HobbyKing_90A_Boat_ESC_4A_SBEC.html

Hoping to try this one out when I get my other project done:
Marine-80HV.jpg

http://www.hobbyking.com/hobbyking/store/__8945__Turnigy_Marine_80A_HV_Brushless_Boat_ESC.html
Problem with that is you need a way to power the receiver. You might want to try the 120a 6s version, its only $43. I filled up my four wheelers the other day, It is cheaper to just buy batteries and ESC's instead of gas!

The 90a ESC has settings for soft/hard brake(if I remember right) and it does have neutral. Works just like a car ESC. I find the braking much better, because of the lack of motor squeal. I should mention that I am using it on a 5065 size motor. I haven't tried it on my other board yet, might have to. I actually didn't think it would last for long because it wasn't going to be water cooled, but it runs cooler than my 150a HK car esc.

Startup is also smooth, no problems there. I also tried the airplane ESC with a car ESC for a bit on my dual motor emt and it would throw me off when the airplane ESC did sync. The boat ESC is more like the car ESC starts. I do always push off, both for myself and the sake of the motors.
 
I been looking at this one.

http://www.hobbyking.com/hobbyking/store/__24754__Turnigy_Trackstar_1_5th_Scale_Sensorless_200amp_8s_Opto_Car_ESC.html

i don't know if anyone has used it before but it seems like a solid choice.
 
Hey torque:

The hk trackstar 200a esc is what I bought for my mountainboard. Still awaiting parts and batts. I've been trying to get more info on performance and reliability. There was only one bad review on here that I could find, but it was by a guy who was trying to run 700kv motors so the esc burned up as any esc would using that motor. If you have other links regarding failed hk ts 200, post some links. It may not be too late for me to send this one back if there is substantial evidence that its not reliable.
 
@Vapology - I honestly forgot who mentioned it. I was considering it myself to get one of those ESCs. Although, they are pretty big ESCs. FlierESC's def trump that one in size and aren't that far off in price range and you can go dual motor setup.

On a side note - I just received 2x 3S batteries for my new dual 6S build and man are they tiny. Big difference between 5S batteries. I'm curious to see if there really is a big power difference between 10S/8S vs 6S/5S. I was going to go 8S on my new setup but decided to just go 6S to go lighter. Supposedly, there's not much difference in torque 6S/8S/10S unless specifically made for torque through the gearing ratio. We'll see.
 
@Torque

I've got a 7S setup by running 2 x 2S and 1 x 3S in series which gives me better ground clearance. I notice a fair difference especially going uphill between 5S and 7S. That's why I'm really trying to find a 7S ESC with decent braking as opposed to using the 6S ESC mentioned in this thread.
 
@Krisbo - Hrm.... now I think I'm having second thoughts. LOL Are you using 2 motors? I've tried my Dual 10S Setup 2x 63mm motors on 10S and 5S for the most part they were pretty much the same on flat ground but up hills 10S was definitely a lot better but the 5S still pulled on pretty steep hills I would just have to keep the momentum going. We'll see. Will definitely try my 6S and see the difference.

Have you tried a single 6S setup? I'm curious to see how well those do. I'm interested in building a single 6S setup as well. I do need the ability to climb hills though. I'll have to see how my dual 6S goes and maybe I'll just go 1 8S or 1 6S for fun.
 
@Torque

I'm running a single motor set-up on my rear right wheel. With a dual motor set-up I would have thought the difference would be less noticeable. Something I've overlooked is that I have a heap of 3S 2200mAh batteries I use for my planes that I haven't thought of using them for testing out 6S on my longboard. I'm just doing a bit of work on my motor mount but I'll give it a go as soon as I'm done.

If 6S is acceptable I might give this ESC a razz because it sounds like a winner.

One massive difference between 7s and 5S a that from a pushing start (I never start from stand-still) 7S will go up hills that 5S will really struggle with.
 
More volts equals higher RPM. KV is your RPM per volt. From experience though a higher voltage does climb hills better. Using a higher voltage in theory only gives you more speed. It does however decrease the amp load on your ESC. Correct me if I am wrong on any of that.

Krisbo-
I'd give that ESC a try. Its only $30. Birdie is however HK's lower grade stuff. The 200a car ESC is a bit overkill unless you are heavy or doing a ton of hills. I need to get a watt meter to see what kind of amps I draw skating. The Flier/Alien ESC's are getting pushed for other reasons, if you check some of the other threads. They are a good option for a dual motor setup, but I'd rather just buy two ESC's for half that price. I am curious how you wired up your 7s batteries. I was under the impression you don't want to mix up battery sizes or even types. So doing two/three/four batteries of the same brand, c rating and amp hours is fine, but one 2s and one 3s in series is not fine? Too easy to kill cells that way. I wanted to run a 4ah 12s setup with a 5a 12s in parallel and was even worried about doing that.
 
I think you've got that wrong there, here's how I understand it. Think of voltage and current in terms or water. Voltage is pressure and current is flow rate. Increasing the water pressure will definitely increase the flow rate. Current increases by the square of the increase in voltage. So if voltage is doubled, all things equal, current draw is quadrupled. I've got a watt meter and more volts definitely draws more amps for me.

Higher voltage climbs hills better because it gives more torque.

I'm with you on those dual ESCs. If one side of it goes, you need to buy a whole new dual ESC as opposed to just replacing one if you've got two. I really don't see the point of them.

I've connected my packs in series with a harness I soldered together. Using LiPo batteries in series you want to definitely match mAh capacity otherwise one will reduce in voltage much faster than the other/s and may get damaged. C rating isn't a huge deal, nor is brand in my opinion although I did buy three batteries of the same brand, series, C rating and capacity. If we look at the difference between my LiPo batteries as the are, two are 2S1P and the other is 3S1P. This means 2 series cells and and 3 series cells. The 1P signifies the parallel width. Sometimes you'll see 3S2P, this means that the battery itself has 6 cells, 2 parallel circuits or three cells connected in series. The way I've connected the my 7S power source is essentially no different to how the company who produces the batteries would sell their own 7S1P batteries. I'm thinking of buying three more of the same batteries to create a 10Ah 7S2P battery. The only difference is I'm not charging and balancing all 7 cells at the same time but I always check my batteries when using them that the cell voltages are within 0.1V of each other. That said, I don't tend to discharge my packs as far as some. I usually shoot for 3.5V/cell. Some guys go all the way down to 3V but with planes I've seen my packs last a lot longer if I don't discharge them too far.
 
I understand it as power = voltage x current. If it takes 2000 watts to get my butt to the top of the hill at 24v I need about 84 amps. At 48v I only need the current to be half that or 42 amps. That is why HV ESCs mostly don't come in higher amps. Most are around 80 amps or so, except the Flier versions. I don't know why your watt meter shows higher amps. That is interesting, unless you are just using more power than you would have available at a lower voltage.

I need to figure out how to use an UBEC so I can get to a higher voltage setup.
 
The only scenario where increasing voltage doesn't increase current is if the power source remains constant. By that, I mean if instead of changing from 4S to 8S, you use a 1:2 transformer, or a voltage doubling circuit.

With the 2000 watts to get you to the top of the hill example, what you're ignoring is that with higher voltage you'll complete the task at higher speed and with more torque. Thus your overall power usage will increase.

*DISCLAIMER* I'm not an electrician or an electrical engineer. What I "know" and "understand" is based largely on my experience building DIY studio recording equipment such as pre-amps, compressors and microphones. So.... I could easily be wrong.
 
I do believe more voltage = more torque since it's getting more power. But there is supposedly a threshold on power/watt ratio where it's too much power and not needed. Ex. Currently, I'm going up hills with a 10S 2x63mm motors. I'm nowhere near full throttle more like 40-50% maybe 60%. If that's the case, I'm guessing a 6S 2x50mm motors wouldn't be that much of a difference. Although, have yet to try it. Will soon.
 
@Torque

More voltage doesn't necessarily equal more torque. If you were to use a transformer to increase voltage then torque would decrease because the amperage would decrease. However, if you increase voltage by using increasing the number of LiPo cells then with this increase in voltage there is an increase in amperage and thus an increase in torque.

In short, more voltage = higher rpm and higher amperage = more torque.

I think the formula for torque is T = (60 * (Power (watts)) / (2Pi * RPM)

So for my motor, using 25.9V and drawing 70A with a 270 kV motor I'm getting a whopping 2.5N.m of torque for my 1.8kW of power (if my formula is correct)
 
Just pulled the trigger on the Birdie 100A with 5A BEC. HK support assure me that it will work as I want it to. Pulling the trigger to accelerate, neutral when the trigger is in the middle and brake as I push the trigger away from me.
 
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