Recommendations new 18V ESC?

nardcox

100 W
Joined
Apr 14, 2020
Messages
103
Location
Netherlands
TLDR: I'm searching for an 18v controller for a small electrical balance bike which has a brushless sensored motor.
Wishes (from important to less):
- On/off switch
- Smooth throttle control
- Soft start / throttle curve adjustment
- Low/adjustable delay
- No/adjustable deadzone
- Determine min and/or speed
- 3 speed settings
- Power cut when brakes applied

Long story

Hi all (again),

I bought my 5y old son a Mondraker Grommy 16 (Google link) electric balance bike because I like driving my Zero FXE and wanted to give my son a taste.

The bike itself is great; lightweight, internal cable routing, good tires, nice rims., etc.
However I believe the controller in this thing is an absolute POS. I'm having the following issues with it:
  1. Throttle delay. The accelerator has a delay of about a second or so making the acceleration very unpredictable and almost feel like a suprise.
  2. Deadzone. The first 20/30% of the travel nothing is happening.
  3. Minimum speed. In the fastest setting (mode 3) the minimum speed is about 8kmph which isn't very comfortable if you just want to cruise on a lower speed or take sharp turns. The minimum speed in the lowest settings (mode 1) is considarably lower.
  4. Max speed. The advertised speeds aren't reached with a full battery, flat ground, lightweight driver.
All of the above feel like errors. I have however checked other bikes and they all act the same, Mondraker themselves also indicate everything is working 'as designed' (they didn't mention they designed a POS). Returning it will cost me around 100 euro minimum so that's not really an option, the alternatives also don't look as nice as this one.

I've driven a KIA eNiro, currently driving an KIA EV6, also tuned a Super Soco TS and as said now driving a Zero FXE so I know that EV's can be silky smooth and lethally fast and this thing isn't either of those (not that I need speed, but smoothness and predictability are nice, especially if someone is learning throttle control).

To clarify some I've made some video's:

Deadzone & throttle delay
New video by Nard Cox

Min speed, deadzone
New video by Nard Cox

Max speed (6 / 11 / 16 kmph)
New video by Nard Cox

Setup:

Now for my question: What to do about this??
Like I said before I think the ESC is the issue here so would it be possible to swap it for a better example?

EDIT: Some notes I forgot:
  • When we drive he always wears protection
  • My son has a normal bike (Volare Rocky 16") and we use that for all day to day stuff. This thing is just to learn throttle control, go with us on holidays, bycling to grandma/dad, going into the woods with dad on his MTB. He will not become lazy, no worries.
 
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Poor quality ESC / bad tuning is the main flaw with a lot of prebuilt vehicles, it's one of the primary reasons i always DIY.
If i click on the link to learn about the bike i get an error because i'm in the wrong country.

In this case i would replace the esc and make sure you get a matching set of throttle and brake handles that go with the new ESC. Be prepared to solder!
 
@neptronix, thanks for your reply. I've added a Google link, that might point you to the 'correct' version of the website based on where you are (the link works fine for me).

Do you have any suggestions for an ESC or ESC/throttle/brake set?
The motor can handle 250W, on 18V that makes around 15A so that's not a lot.
A small size would be appreciated since the packaging it's need to be in is rather small.
3 speed settings would also be nice, but most importantly it needs to be smooth.
Does it need to be a specific typ so that it works together well with my motor?

I found the following: 18 Volt Electric Scooter Speed Controllers - ElectricScooterParts.com

I will most likely not be able to use the battery indicator on the little screen.
But can I still use the battery, it might have a BMS build in that needs modification.

I can also buy a (5S) LiPo or build my own small battery (I have 10 Samsung INR18650-29E E7 2750mAh - 8.25A laying around from my Super Soco TS project).
 
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Ah, that's a brushed motor.. super old technology which is rarely used around these parts..

1718719835799.png

There aren't many high quality brushed programmable controllers in this power range and you can expect some hit/miss in finding one. The best bet is to buy a larger controller than you need and tune the power down so you get the programmability features /refinement... instead of hoping that a non programmable controller is configured correctly.

My best guess would be to look at 4QD controllers. Hopefully someone else has more knowledge of this.
 
@neptronix, may I ask how you can see it's brushed? I did specifically select the bikes on having a brushless motor since brushed sucks (less effective, maintenance, loss of power, etc).

The website clearly states: Motor MDK brushless 250w Output

EDIT: I do believe there are only 2 power wires coming out of the motor where brushless typically have 3 I believe...
EDIT: I stand corrected, looks like there are actually 3 (though hard to see).
EDIT: I've looked at the 4QD and the Porter5 looks like the way to go for me.
EDIT: Correction, they are only for brushed motors, I believe/assume/hope I have a brushless one.

Removed reaction to above post.
 
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I deleted the above post because it was way abusive.

@neptronix, may I ask how you can see it's brushed? I did specifically select the bikes on having a brushless motor since brushed sucks (less effective, maintenance, loss of power, etc).

My bad, from the picture it looks like a 2 wire system from the picture. You also linked to a brushed controller. So i figured, ok, it's brushed.

How sure are you this is an 18 volt nominal system?
How handy are you with a soldering iron? replacing a controller is going to require one.

Good candidate is something like this. Totally programmable, and quite low latency on the throttle. Cheaper versions of this do exist, but this is the nice original one. It will require a different throttle/ebrake ( you're using scooter parts now ).
VESC SIX Education - with IMU

^-- cool because it will work in that 6v-26v range ( and 18v nominal lithium battery should be 21v fully charged ).

The VESCs are pretty nerdy and have a high learning curve but there aren't many brushless controllers that operate at such a low voltage that are also programmable / not total junk.
 
@neptronix, first off many thanks for your time and information, it's highly appreciated!

I didn't even realise I linked to a brushed controller, my bad. It's been a while since I was working with stuff like this.

The Grommy uses a 'standard' drilling machine battery config that slides and clicks in place which I guess has 5 cells in serie making around 18V nominal. Purebike

I can solder a bit, also had to solder when I upgraded my Super Soco TS.

The VESC sounds familiar, it def looks like a solid piece of kit and highly customizable but wondering if it might be overkill for this. Next to not being very cheap considering I would also need a new throttle (and potentially ebrake). Not planning on going full geek like this. Do you have any cheaper alternatives?

Things I would like most is to fix my original complaints
- low/adjustable delay
- no/adjustable deadzone
- determine min/max speed
- throttle curve adjustment / soft start
Nice to haves
- 3 speeds
- potential cut-off when brake applied (current one doesn't, it's a mechanical brake only)

Would something like this work or is that a stupid suggestion:) Platinum 25A V4 ESC (3S-6S)
 
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Ya welcome!
Interesting that this bike uses a powertool battery like that ( kind of genius TBH )

That hobbywing unit looks good and the brand is said to be high quality but it seems sensorless and i'm betting your motor has a hall connector on it.
The consequence of not using the halls is that, no matter how well you tune it, it will be a little jittery when you hit the throttle from 0RPM. This means that kiddo would need to kick start it for a smooth takeoff or just accept the jitters.

I currently run my VESC sensorless on my ebike and i don't mind this too much but maybe you or kiddo are pickier than me.
Another thing is the hobbywing might not easily adapt to a typical throttle and brake switch.. it wants to go through a wireless reciever.. so you need to figure that part out - it's very clearly made for RC vehicles, but the VESC was originally made for scooters.

Yes, the VESC is a nerd's toy, but i've found there's great support for it on this forum and they are becoming more popular as time goes on.
 
Yeah, there are actually bike brands (I know of a German one) that uses the same mount as Makita meaning you can simply use your powertool batteries as a direct drop-in.
Unfortunately my Makita XTs dont fit in the Grommy but might be able to modify it so it does.

I've used HobbyWing products during my RC period many many (many) years ago and they never failed me. However if they can't handle a normal throttle input I'm not going to go down that road, then it might be better to search for another alternative made specifically for scooters.
 
Been searching a bit more on ES but can't find a 'list' of generally recommended controllers or perhaps a guided step by step program that can help in identifying brands/models that are solid.

Most controllers I find start at 36V (like the VOTOL EM30S) which is way to high. Unless I mod the battery to not be 5S2P but 10S1P... But if I would like to use my Makita batteries as well that will not be an option since they need to stay at 18V.

Would this be a viable option? https://vi.aliexpress.com/item/32743738442.html
 
Yes, brushless controllers usually start at 36v.

I wouldn't know about that controller, it looks like it might be quality, but you are dealing with a small Chinese vendor and taking a risk on it. Don't expect good customer service if you have a problem. Buying cheap stuff on aliexpress is kinda like playing the lottery..
 
Yeah I guess you are right. Downside is I live in the NL meaning I have to add shipping and import cost which will make it around a 160 euro (just a rough guess) for just the controller, that's quite a bit on a bike that only costed 500 in total. Plus then all other mods required, it gets expensive fast hence I'm looking for cheaper alternatives. Perhaps less good but the amount of features isn't required so feel like I'm partially paying a bunch for stuff I don't need.

I'll keep searching for a bit, till then we just have to 'make do' with what we got.
 
Oh; would be helpful to put your location in your profile, even if it is just your country. That way you can get better recommendations.

This thread is also titled 'mondraker grommy 16', you might want to start a thread about an 18v compatible ebike controller or ESC; it would probably get better visibility and responses.
 
It was under 'identities, country' but not under location, anyway just updated it, I see it in my profile now as well.

Good tip about the title, adjusted it.

EDIT: Also added a TLDR since the it's not all relevant anymore since we are (pretty) sure it's the ESC.
 
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I found this thread by googling the same problem I have with the same bike. All the remarks are right on point and highlight the same issues. I have two Surrons, LBX and Ultra, and I know how good these bikes are. Unfortunately, this kid's bike controller is just not up to par.

I'm actively seeking a solution. I have all the necessary tools and knowledge to build a new controller if needed, but time is a constraint. If there's a plug-and-play option available, that would be the ideal solution for me. I have various tools and both 18V and 36V batteries. The 36V battery from one of my tools barely fits the frame, so ideally, I'd prefer to stick with 18V if possible.

Regarding using tools' controllers, I'm concerned they may not provide a smooth enough experience for the bike. I own over 30 different cordless tools, but I doubt any motor and controller combination will deliver a better experience without quickly overheating due to their design limitations. If I'm mistaken, please correct me—I'm open to disassembling a tool and adapting it if it could work better.
 
If your looking for something that gives you full control i would suggest vesc.

At the minimum you will need a laptop and to sign up to vesc website for free to get access to the software, once installed its simple enough theres loads of guides on youtube.

Id suggest getting a vesc 6 something like the one below if you dont want to go to mad, but it will give the ability to adjust power output and low voltage cutoff.


From the size restraints id say its a close fit, but of soldering swap over connectors etc and program it no doubt it will give the best gains to value results.
 
Thanks for the link. I will try this and let's see how it goes. However, the price of this for Europe comes close to €150. Controller + $35 shipping and they will add 25% tax here. I can't complain as I have €1k controllers on my bikes, so I can't say that €150 is too much for my kid :)
I'm also a bit confused about connectors. Do I get connectors with the board or not? Can communication I probably won't use without a display, but a sensor and comm connector would be handy.
 
Yeah, I believe there must be an EU version of something like that available right, the other one was from the UK but we have the same import issues.

I haven't actively worked on the bike yet, so has been driving more and more though so I'd also like a better solution that the current POS.

Those controllers are a bit overkill for the low power output we require. Would be nice if there would be a cheaper lower power version.

Keep me posted @gachot666.

PR. Something like this?
 
Stick with vesc 6 i would it has phase filtering and juat suita your needs better plus has more features like auto on off built in power down, just push the ride and it will turn on 5 mins or so inactivity turn off automatic , the 84v controllers handle more power but just not as refined, let us know how things go.
 
@scianiac, thanks for the tip!

@Ianhill, unfortunately it's missing 3 speed settings. Meaning there will be no on the fly adjustments right? Since it works with USB so I guess no quick BT adjustments possible.

Whats the difference with this one: FLIPSKY Mini FSESC6.7 PRO 70A base on VESC6.6 With Aluminum Anodized Heat Sink.
Or is it only the Phase Filtering? On Ali it's about 30% cheaper (94 vs 67 euro)

EDIT: Answering my own question: Differences Between FLIPSKY Mini V6.7 Pro and Mini V6_MK5

Ahh, there is a bluetooth module available I see.
 
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I had the bluetooth module on a vesc 6 with the vesc android app the level of detail is unmatched theres even the ability to run daughter boards esp32 etc.
Headlight, brake light control, rgb led lights that move as the ride speeds up hsing the hall signal police lights etc electronic horns all sorts vesc is very versitle for a basic programer and opens a new world of exploration, can tell im a middle aged kid lol.
 
I did order mini V6 as recommended and it just arrived. I've paid more in shipping, taxes, and import handling than the price of the controller. I have it on my desk and now I have to learn everything. Downloaded the Windows VESC app and let's see.
The main problem is the lack of Bluetooth; now I see a module for it. So, naturally, I have to order one.
I'm thinking ahead and wondering how I will know motor settings. It will be interesting. I will try to do some basics, but there is a problem. If I remove the original controller now, the kid will not have a bike until I make this work. That is a problem :)
 
@gachot666, yeah that price is a bit I was worried about, just sounds like a shame to pay more for other stuff than for the product itself.

Regarding motor settings, perhaps the controller can 'auto learn'?

Just got back from holiday today so haven't ordered anything yet, but think about buying me a FLIPSKY VESC and seeing how far I'll get. Didn't even consider not having the bike available will deff be a 'thing', means I should only start when I have decent time available to finish it as well..

Keep us posted on your progress!
 
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