Better than the Stark Varg? 76v 90Ah 35kw Dirtbike Build

[Blacksheep Engineering]

Update on this, waiting on parts, I am going to use 3 6 gauge wires inside the battery. Hopefully 2 gauge after that but I cant find a connector that can fit anything bigger than 4 gauge. What are you guys using? Anything better than a QS-10?

Is there any reason not to run wires straight out of the battery to the controller? No connector? I dont think unbolting the leads from the controller to remove the battery is a big deal. I'd have a separate charging port like one of those panel mount XT-90s. Then there is nothing limiting my wire size all the way to the controller.

 

[lightbulb010]

I'm using a QS10 with 4 gauge. 450A peak. I've never noticed any heat in the cables or the plug. There are very large Anderson connectors like the ones electric forklifts use. Depending on whether or not you plan to remove the battery often, you could put ring terminal lugs directly on the battery wires and connect it to your controller or fuse etc... Then use a separate connector just for charging purposes.


EDIT:
BTW, I just got one of those 4875G chargers. It's awesome! Exceeded my expectations in every way. I got a 66-93v version so YRMV with the higher voltage version but this thing is seriously powerful. I haven't yet tried to run it on 240v but it can blow the 15A breaker in the garage on 120v! The Bluetooth functionality is nice. It allows you to monitor the input current so you won't overload your outlet. It's a beast!

You must have edited your post as I was replying haha. The one obvious reason for a connector is to avoid accidental shorts. That battery will be capable of some ridiculous currents so be careful! I would probably tape up one lug as soon as I removed it just to be safe, but other than that I see no reason a connector would be totally necessary.

 

[dominik h]

I have the QS10 as connector for fast charging.
The wiring from battery over fuse and BMS to the controller has no connector. Everything is screwed.
Connector is only needed when you want to remove the battery often.
As I never again want to remove the 70kg battery from my scooter, I have no need for a connector.

 

[Blacksheep Engineering]

Ok, Im planning on direct connections to the controller and a surface mounted XT-90 for charging.

Im looking for a throttle and I cant find one that says it works with normal grips. Normal throttle tubes would be great too. Does something like that exist?

 

[harrisonpatm]

Something like this?

https://www.aliexpress.us/item/2251832768594256.html?spm=a2g0o.order_list.order_list_main.10.565e1802wEX9bk&gatewayAdapt=glo2usa

Lets you use basically any throttle, and you just need to stick that twister thing somewhere else on the bike.

Another options comes with a throttle body and grips if you want to go that route:

https://www.aliexpress.us/item/3256802873414534.html?spm=a2g0o.order_list.order_list_main.5.565e1802wEX9bk&gatewayAdapt=glo2usa

 

[Balgaroth]

Ok, Im planning on direct connections to the controller and a surface mounted XT-90 for charging.

Im looking for a throttle and I cant find one that says it works with normal grips. Normal throttle tubes would be great too. Does something like that exist?

So far I have been doing some research about this too and aside from the mechanical to electronic solution suggested above, you could either go for a Stark/Alta throttle which isn't cheap, or search for some Surron type throttle (like this one) which you can find without grip like a regular throttle tube. Obsviously that second option is a lot cheaper. I think I will start with this and if I can't get good results from it I will get a Stark throttle. While I considered the mech/elec solution for a while, I feel like this adds components and complexity that is unnecessary and kind of defeat the purpose of electric bikes (less parts, less maintenance).

 

[Blacksheep Engineering]

I agree with avoiding the extra complexity. Looks like a reputable surron throttle isnt too expensive. I'll be running hand guards so hopefully I wont be busting my throttle tube often. I'll just get a new throttle if I do.

Project update:
Got parts showing up! Pardon the mess lol this is my catch-all bench.
-I got the custom busbars from ken. He said he'd include extra pieces to practice spot welding on! but he didnt. but I reminded him and he shipped me some! but I had to pay shipping again and its currently a week after the date he said it would be here... He did send me a sad face and a flower emoji when I asked him about it though so I guess that makes it all better.
-The ND961800 controller weighs about as much as a whole Chinese electric bike (with rider).
-The BMS looks almost identical to the one I already have other than the extra balance wires.
-The flush mount charging plug I got is somehow the male side of the xt-90 plug? So it wont fit the cord that came with the charger.

I got some 2024 kx250f plastics since I couldn't find grey ones for the 08 and I'm unreasonably picky. Surprisingly, not a single hole lines up with the 08 frame. Figured at least something would lol. I'll be chopping up both the frame and the plastics so I'll get something figured out to hold them.

The cell holders are getting routered out of ABS and as soon as they're done I should be able to start the assembly.

 

[speed.hertz]

Im looking for a throttle and I cant find one that says it works with normal grips. Normal throttle tubes would be great too. Does something like that exist?

I purchased this Domino throttle and while I haven't used it yet, the build quality seems high and the brand is reputable. It comes with the soft rubber grips pictured which I have to imagine are standard removable grips.

Domino 0-5 kΩ Twist-Grip Throttle

<p><span style="color: #ff0000;"><span style="color: #2f2f2f;">This compact and light-weight twist-grip throttle by Domino S.p.A. features a 5 kΩ IP-54 rated potentiometer, built-in microswitch, and Tyco sealed connectors. The microswitch is a nice

www.electricmotorsport.com

 

[lightbulb010]

Those bus bars look great!

 

[Dui ni shuo de dui]

So far I have been doing some research about this too and aside from the mechanical to electronic solution suggested above, you could either go for a Stark/Alta throttle which isn't cheap, or search for some Surron type throttle (like this one) which you can find without grip like a regular throttle tube. Obsviously that second option is a lot cheaper. I think I will start with this and if I can't get good results from it I will get a Stark throttle. While I considered the mech/elec solution for a while, I feel like this adds components and complexity that is unnecessary and kind of defeat the purpose of electric bikes (less parts, less maintenance).

In this case the "extra complexity" ends up in a more reliable throttle.
The reason is that you can hide the electonic part away from water/rain. It makes a big difference safety wise and makes it way more reliable.
I had a regular throttle going full speed once during a storm because rain got in, I can guarantee you it's not fun.

Added bonus: the throttle feeling is also much better with these cable actuated things. Feels like a real motorcycle throttle where the others just feel like cheap toys. Last but not least, it's much cheaper to replace in case you crash since you can just use pretty much any kind of motorcycle handle (which gives you a lot more design options also).
And it's probably even cheaper to purchase the entire system in the first place.

I can't think of any real advantage of using other kinds of throttles, really.

 

[Dui ni shuo de dui]

I couldn't find grey ones

Maybe that's a dumb question but could'nt you just buy paint?

 

[lightbulb010]

In this case the "extra complexity" ends up in a more reliable throttle.
The reason is that you can hide the electonic part away from water/rain. It makes a big difference safety wise and makes it way more reliable.
I had a regular throttle going full speed once during a storm because rain got in, I can guarantee you it's not fun.

Added bonus: the throttle feeling is also much better with these cable actuated things. Feels like a real motorcycle throttle where the others just feel like cheap toys. Last but not least, it's much cheaper to replace in case you crash since you can just use pretty much any kind of motorcycle handle (which gives you a lot more design options also).
And it's probably even cheaper to purchase the entire system in the first place.

I can't think of any real advantage of using other kinds of throttles, really.

I would have to agree with this. I have that setup too. Cable throttle with the TPS sensor thing. It does feel good. I even have an extra throttle box in case it fails. Keep it in my backpack with my emergency tools. Hadda layer down once because of the clibbins and the throttle still worked despite the bike landing on that side on blacktop. Not sure one of the plastic e-throttles would have survived that.

 

[Blacksheep Engineering]

You guys bring up good points with the throttle situation. I already have a surron throttle on the way so Im going to try that first, I enjoyed the throttles on the surrons I used to have and I definitely got them soaking wet a number of times without issues. I think the build quality of those is better than the cheap ones all over aliexpress. I ordered one of those $5 ones a while ago to tear it apart and its pretty terrible. I definitely would stay away from those.
If the surron throttle gives me any grief I'll try a cable setup next.

As far as the paint goes, I've never seen painted plastics that look as good. Especially on a dirt bike that is definitely going to end up getting the tar beaten out of it. It would get scratched through and cracked. I think these plastics will look awesome on there when Im done.

 

[j bjork]

I have used a few different throttles, mostly more or less cheap e-bike throttles.
I think most work just fine, and a have run them in wet conditions. Even under water a few times, and havent had any problems.
But it can be a good idea to open up and see that there are decent insulation between the connections to the hall sensor.
They dont last very long though, 50+ hours I suppose on a dirtbike.

I think the surron throttle feels good, but it is very aggressive. I had to modify my throttle map to make the bike rideable when I changed. I suppose they made it that way to make the surron feel less underpowered.

I think you should paint as little as possible on a dirtbike, if it is a steel frame you better paint that.
Paint the plastics is not a very good idea. They get hit, bent and scratched all the time. The paint would get scratched and just brake off in pieces.
That is if you use it of course. Some seem to just show off the bikes, then I suppose it works.

 

[Blacksheep Engineering]

This is going to be a really satisfying build...

 

[gustavo88py]

what version of qs138
70h or 90h

 

[Blacksheep Engineering]

what version of qs138
70h or 90h

70H

 

[Blacksheep Engineering]

I did some spot weld testing with the K-weld on the battery connections I got from Ken. They held up to a lot more joules than I thought they would.

 

[halg]

This is going to be a really satisfying build...

Would you be willing and able to share the design files you used for those battery holders?

I am starting a build of my own on a KLX400 (green DRZ) and wonder if the layout would fit. It is not a twin spar frame like yours but it would be great to have to a starting point even if I have to change it.

Also, thanks for making those youtube videos. I'm following and looking forward to updates.

 

[Blacksheep Engineering]

Yeah of course, I'm working on getting a website together to organize that stuff so its easy to get back to. For now, heres the STEP files. If you dont want the ribs between the connectors, you could have a common part for all 4 but if you're picky like me, each one has to be different. Thanks for the support!

 

[amberwolf]

, I'm working on getting a website together to organize that stuff

Some people use Github for that (even when it isn't code). I don't yet know how to use it, but eventually the Snuggles The Wolf - robotics project will go up there.

 

[halg]

Yeah of course, I'm working on getting a website together to organize that stuff so its easy to get back to. For now, heres the STEP files. If you dont want the ribs between the connectors, you could have a common part for all 4 but if you're picky like me, each one has to be different. Thanks for the support!

Many thanks.

I will second a github repository. It is a great place for a group of people to store, track and collaborate on any set of text based files. Controller configurations come to mind as something it would be nice to share and track although I got a votol for my build which apparently uses binary files for their configuration which is unfortunate. Seems like vesc configs might be text based so I would be happy if that proliferates through the industry.

 

[A-DamW]

Seems like vesc configs might be text based so I would be happy if that proliferates through the industry.

I think they are XML based. (eXtensible Markup Language)

 

[amberwolf]

on any set of text based files.

AFAIK it also supports images and compressed file sets, based on the things I've seen in repositories for projects I've peeked at and followed, but I don't know what the limitations of those are.

 

[halg]

AFAIK it also supports images and compressed file sets, based on the things I've seen in repositories for projects I've peeked at and followed, but I don't know what the limitations of those are.

yep. you are right. git repos can handle a wide variety of file types. however, one of the primary features of git is that it can show differences (diffs) in what was changed so it can be reviewed by a group in a request to merge the changes into a file or set of files. this is not the case when the file is not text based.

i don't want to clutter this thread too much about git repositories (edit: or a debate about what git can and cannot do) and how a software development workflow could benefit groups of people collaborating on a set of EV related files. however, i'm happy to discuss this topic on another thread.

finally, thanks for your contributions to this forum. i have learned a ton here and look forward to applying it soon.