large road legal electric go kart build. need help!

Electric cars, trucks, ATVs, NEVs - things bigger than a motorcycle.

Re: large road legal electric go kart build. need help!

Postby nuxland » Mon Apr 10, 2017 3:08 am

falshami wrote:are you saying that with the VEC500 48v model, we can actually run as high as 60v safely and run the 10kw motor also at 60v? what kind of power did you squeeze out of that?

Here is my controller inside fets
VEC500.jpg

Here is one of the last races I was using this combo
https://youtu.be/v_uUkrmJ_1c
Battery amps were lower than with 48V battery (mybe VEC500 lowered it somehow because I had the same parameters when using 16S lifepo4)
So I only gained more rpm, but power was before also around 13kw.
User avatar
nuxland
100 W
100 W
 
Posts: 102
Joined: Sat Apr 04, 2015 2:18 pm
Location: Tallinn

Re: large road legal electric go kart build. need help!

Postby falshami » Tue Apr 18, 2017 3:05 am

im confused how you keep pulling 13kw, what is your programming? i struggle to get 7kw out of my motor, i think that maybe 60v or in that realm may be more helpful? i just dont know what to do with my 48v charger, i wonder if i can reprogram it as well?

i have put a 5:1 ratio and it seems that my buggy now only does 22mph again, from 45 mph when i had it at 2:1 but it had no torque... im at a bit of a loss... am i just not getting enough power to spin up?
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby Hillhater » Tue Apr 18, 2017 4:10 am

What motor rpm are you getting ?
Did you check the ratio in the axle diff ?
This forum owes its existence to Justin of ebikes.ca
Hillhater
100 GW
100 GW
 
Posts: 7958
Joined: Tue Aug 03, 2010 10:33 pm
Location: Sydney ..(Hilly part !) .. Australia/ Down under !

Re: large road legal electric go kart build. need help!

Postby nuxland » Tue Apr 18, 2017 6:14 am

falshami wrote:im confused how you keep pulling 13kw, what is your programming? i struggle to get 7kw out of my motor, i think that maybe 60v or in that realm may be more helpful? i just dont know what to do with my 48v charger, i wonder if i can reprogram it as well?

I bought me a new charger when upgraded from 16s to 20s. But you do not need 60V to get 13kw out of that controller.
Here is one of my conf from 2015-06-10
Controller_Settings_20150610.jpg

falshami wrote:i have put a 5:1 ratio and it seems that my buggy now only does 22mph again, from 45 mph when i had it at 2:1 but it had no torque... im at a bit of a loss... am i just not getting enough power to spin up?

Here is another video I found in my harddrive, when I tested 16s vs 20s. As you can see I got about 300 more rpm in the straight end and as battery amps were the same I got also more kw-s in to the controller. All that was saved by cycle analyst analogger and rpm were calculated from the speed that was measured from the rear shaft by cycle analyst. I had 300A shunt between minus battey wire and from there I got battery amps.
https://youtu.be/_HKTkKx89e8
User avatar
nuxland
100 W
100 W
 
Posts: 102
Joined: Sat Apr 04, 2015 2:18 pm
Location: Tallinn

Re: large road legal electric go kart build. need help!

Postby falshami » Wed Apr 19, 2017 5:18 am

ok so first off, can our controller take a cycle analyser? i dont see a connector for it, also any idea why our controller has two of the same plugs on it? . your settings look amazing, i have mine currently set at 75 starting phase amps. that may be a bit of the problem. next your forward loop is set WAY higher than mine which may be another issue, my shunt is reading a peak of maybe 130a from the battery. i had a feeling my motor controller settings were wrong and tomorrow i now get to go find out since i do beleive this setup should be able to get me to at least 45mph. and that is hunky dorry for regular traffic. also what charging system are you using ?


thank you so much for posting !! this may be my fix we will see tomorrow
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby galderdi » Wed Apr 19, 2017 6:21 am

The cycle analyst is an independent device. It has it's own shunts etc. No need to connect to your controller.
galderdi
1 kW
1 kW
 
Posts: 306
Joined: Tue Sep 08, 2015 8:17 pm

Re: large road legal electric go kart build. need help!

Postby falshami » Wed Apr 19, 2017 11:14 pm

how does it measure rpm then?


sp update, the new settings were awesome they relally helped the buggy get scooting, i had to leave the throttle type as hyperbola which really slows the start up but prevented it from tearing my transmission to bits. it was crazy torquey on linear. i tried with 4:1 and i got 24mph... then 3:1 and got to 31.2 mph at 46 volts... so at least were moving up now. unloaded the motor spun up to 4200rpm which confuses me as well, since i beleive unloaded it should spin at 6000 rpm, and loaded at up to 4500 rpm? so according to the calculator i have if i maxed at 31 mph that means my motor underload only did 1300 rpm? so what am i missing here?
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby falshami » Thu Apr 20, 2017 7:17 pm

also as a further update, my shunt has read that it wont exceed 130 amps from the battery which again has me lost... is a 96v setup what i need? what will i gain from this?
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby nuxland » Fri Apr 21, 2017 1:36 am

falshami wrote:also as a further update, my shunt has read that it wont exceed 130 amps from the battery which again has me lost... is a 96v setup what i need? what will i gain from this?
One thing I can think of, if your bms/battery is not restricting the current and you have set more thatn 130A battery current in the controller.
Have you measured what voltage your acceleration pedal will input to controller? And have you configured your controller according to these throttle voltages?
With that VEC500 controller, its torque driven and when wheels off ground even half or less throttle will give you max rpm. But when wheels down and half throttle it will give you only half torque and therefor also less top speed.
User avatar
nuxland
100 W
100 W
 
Posts: 102
Joined: Sat Apr 04, 2015 2:18 pm
Location: Tallinn

Re: large road legal electric go kart build. need help!

Postby falshami » Sat Apr 22, 2017 12:06 am

Ok so further update today, got her up to 42 mph , using a 17 tooth on my motor and a 31 tooth on the axle, it seems that nothing in between gets me to where i need to be, this time it pulled about 216 amps, so it really needed a heavy load or else it wont use the amps it can push out, i guess i need to try maybe a 13 or 14 tooth and see if that helps get me a happy medium? im guessing with a 10kw motor it wont do more than 45 mph, does that seem reasonable? and without ehavy loads it will never use the full power at its disposal due to torque vectoring... when i did 5:1 i got literally 24mph. with great acceleration. when i do 3:1 i can touch 36 mph with decent acceleration, when i did nearly 2:1 i got poor accleration but got up to roughly 41mph... im at a tad of a loss. your thoughts folks? also learned that the person who told me that my wire could handle 10kw was full of crap :) BIG explosion and now rewiring for larger gauge wire haha! missing an eye brow and eye lashes but all is good !
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby falshami » Sat May 06, 2017 1:59 am

Update!!! i switched to direct drive, and used a 14 tooth to a 31 tooth, its less aggressive than the 18 tooth i was running, she starts slow but eventually picks up and we yielded a result of around 46 mph on what might have been wither a slight down hill or flat road. i successfully ran for 12 miles, motor was warm, so i still need to run the watercooling. however my bottle neck now is the controller. it get very hot, and i have no idea how to cool it , fans wont really work since its a huge block of aluminum, and i dont think they make watercooling blocks for this? its a vec500. or am i going to have to jimmy rig a cooling system out of a bunch of different smaller cpu cooling blocks? i think the controller was bottle necking itself once it reached a certain heat point. which means continuous runs will be tough. does anyone have thoughts? also we were cruising at about 200 amps... so that range is going to be around 45 minutes driving time but thats going to be consistently dropping voltage as well so im not sure how well she will be driving at that much draw. my work is 14 miles away roughly. and i can charge up at work. so i may have to re enable re gen since i havent quite done that yet. and i will absolutely have to throw my solar panels on there if anything to just help tun my accessories. although 240w should yield an extra few miles every hour it charges. thoughts guys?
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby falshami » Sun May 07, 2017 1:16 am

New update! I foxed the controller overheating issue. I grabbed two beefy Intel Xeon server heat sinks made them flat threw some heat sink compound on them wired them up to a thermostat and baam! They turn on and off with the thermometer. New temperature for operation was closer to 100 to 110 ! Great success and I saved money! Vehicle is just reaching acceptable power outputs. I realize now it should have been a 20kw motor. Along with controller. However I manged to get speeds around 45 mph. However I'm still trying to make My range more efficient I got me a smaller sprocket. 12 tooth this time so we shall see how it does. Maybe lose a couple miles per hour but if it gets me to around 150 amps cruising I will be doing very well! I haven't figured out regent yet and why it isn't doing anything. However I had my first failure. It was weird. I was going up hill around 42 mph and the fuse just gave out. It was supposedly rated for 400 amps. I think it did closer to 250 when it went out. I swapped in a 250 fuse to get me hone and it managed to get me up to 35 mph cruising home. I was trying to not blow another fuse. I could smell it burning up earlier I just didn't realize what it was.. I think the vec500 has an underrated fuse. Overall Much happier with it. Currently I think it has close to a 20 mile range. Single occupant. I need to double that and to do so I need to be under 150 amp draw I think. What a catch 22. I'm afraid that with another person the buggy may bog down a lot as well. Since at take off it still struggles. But once going she really moves! Decent acceleration in motion
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby falshami » Sun May 07, 2017 1:19 am

New update! I foxed the controller overheating issue. I grabbed two beefy Intel Xeon server heat sinks made them flat threw some heat sink compound on them wired them up to a thermostat and baam! They turn on and off with the thermometer. New temperature for operation was closer to 100 to 110 ! Great success and I saved money! Vehicle is just reaching acceptable power outputs. I realize now it should have been a 20kw motor. Along with controller. However I manged to get speeds around 45 mph. However I'm still trying to make My range more efficient I got me a smaller sprocket. 12 tooth this time so we shall see how it does. Maybe lose a couple miles per hour but if it gets me to around 150 amps cruising I will be doing very well! I haven't figured out regent yet and why it isn't doing anything. However I had my first failure. It was weird. I was going up hill around 42 mph and the fuse just gave out. It was supposedly rated for 400 amps. I think it did closer to 250 when it went out. I swapped in a 250 fuse to get me hone and it managed to get me up to 35 mph cruising home. I was trying to not blow another fuse. I could smell it burning up earlier I just didn't realize what it was.. I think the vec500 has an underrated fuse. Overall Much happier with it. Currently I think it has close to a 20 mile range. Single occupant. I need to double that and to do so I need to be under 150 amp draw I think. What a catch 22. I'm afraid that with another person the buggy may bog down a lot as well. Since at take off it still struggles. But once going she really moves! Decent acceleration in motion
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby galderdi » Sun May 07, 2017 8:42 pm

Nice work. Sounds like you are almost there.

If it is struggling at take off it indicates you've probably tended towards the "top end" side of the gearing compromise. But its probably not worth anymore gearing changes by the sounds of it. I am assuming you are still running a single ratio?

If the performance you are chasing is from 0mph then weight reduction is the key. If the performance you are chasing is around 35-45mph then aero improvement is probably something to consider. Of course this is assuming you can't squeeze any more from your Motor/controller combination.

But if you aren't sure why not try both :-) You have plenty of spare time, right???

As for passengers....give them some peddles.
galderdi
1 kW
1 kW
 
Posts: 306
Joined: Tue Sep 08, 2015 8:17 pm

Re: large road legal electric go kart build. need help!

Postby falshami » Sun May 07, 2017 11:02 pm

thats actually quite genius... if you could have them pedal and generate power that would be lovely!, i want to get my regen working to see if i can use it for braking as well as for getting some power back.i popped on my solar panels today and will hook them up sometime this week to charge, i just want to be able to put in a hard switch so i can control when they are on or off and not damage my battery. So my aero dyanmics are in the works, the bottom will soon be sealed up to help aid in that, as well as sealing up the front. next i will be seing if there is weight to be removed but shes fairly bare bones... the only extras are a stereo... its good for maybe 35 pounds? i think realistically its going to a 96v system that will fix my issues. but for now she must stay as such. and i will be moving down toa 12t sprocket on the motor and i think that will be my healthy balance of speed and torque, on a recent run she saw 49mph, might have been downhill but before she couldnt do that on a down hill so im going to say its still a win, the battery only lasts roughly 20 miles, so i am hoping that dropping two teeth will extend my range , drop my over all amps a little if possible and speed up my acceleration, also dropping from 18 to 14 teeth did help my top speed as well which made me happy, iam confused though. my 400 amp fuse blew out on an uphill run, which was confusing since.... nothing was warm, my controller was at a cool maybe 100 degrees? so i put in a temporary 32v 250a fuse... and it did me just fine all day today i didnt push it past 220a , but it held up since realistically even 220a is further than what that fuse should have done. so any idea why it did this? a 400a fuse that died before it should have, but a smaller fuse that ran just fine and didnt even get warm! i am confused as to what is going on there. i am going to reprogram my controller tonight to see if i get my regen working at least. overall i am very proud, id be much happier if i got to at least 25 miles range, also once i get up to speed its weird because the motor doesnt keep up with the wheels so i have to let off the throttle for a bit then give it again or it doesnt seem happy, any body else experience that?
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby SlowCo » Mon May 08, 2017 11:15 am

I'm still following this thread hoping for more photo's of this project. There are lots of build threads with bicycle photo's but more photo's or video's from builds of larger EV's would be welcome... :wink:
Keep up the good work!
SlowCo
1 kW
1 kW
 
Posts: 454
Joined: Mon Jan 05, 2015 5:43 pm
Location: The Netherlands

Re: large road legal electric go kart build. need help!

Postby galderdi » Mon May 08, 2017 10:53 pm

Keep in mind the percentage return from regen is fairly low. I just don't want you to get your hopes up thinking you'll get 80% return or anything.

It sounds like it might have just been a faulty fuse. The only other explanation I can think of is that the 400amp was rated at a lower voltage than the 250amp?

I am not quite sure what you mean by the motor not keeping up with the wheels? Do you mean that when you approach top speed the motor won't accelerate any further, then by releasing the peddle the the speed reduces and then applying the peddle again results in another burst of acceleration up to top speed again? If that is the case it is likely the motor/ voltage combination has reached it's limit. One way to know is to pick a stretch of road, try it while your battery is full and measure the top speed with as much accuracy as possible. Then use up some battery charge, as much as possible while still leaving enough for another test. Then redo the same test with the same weight in the car. If the same thing occurs at a slightly lower speed then it indicates the voltage is the problem.
galderdi
1 kW
1 kW
 
Posts: 306
Joined: Tue Sep 08, 2015 8:17 pm

Re: large road legal electric go kart build. need help!

Postby falshami » Tue May 09, 2017 2:17 am

Slow co. My apologies. I will get more photos and videos up soon. As far as this whole fuse thing.I am bewildered. I installed a 250 amp 32v one for a temporary use... And today it easily withstood over 320 amps for quite a while.so i am totally confused on that.
I decided to test my 10 tooth gear again. And starting acceleration was still abysmal from the start even at 350 starting phase amps but my god when moving did she pull. It was crazy. I got a top speed of 38 mph. And the motor really could spin up quickly. This was at around 47v I'm astounded that the buggy pulled more amps with a smaller gear. I don't know why? I'm guessing that my in coming 12t sprocket will by my Goldilocks sprocket. And they will all suck upon take off. And what I mean by my motor spinning is. Imagine a car. When you want to hold a speed you just hold the pedal in a certain position. In This buggy when I get to said speed I want to hold. If I leave my foot on the pedal. It either continues to accelerate. Or you will hear the wheels moving g the chain faster than the motor is spinning and it makes a weird noise. As if all tensions leaves the motor for brief instants and the chain just gets loose and taught loose and taught.
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby falshami » Thu May 11, 2017 1:37 am

So further update today. this little buggy is a fun little conundrum. im always surprised at the stall torque. at the start on a slight incline you can feel the buggy want to stall as the motor slightly stutters, but as soon as she start moving there is definitely torque and after a certain rev range you can feel her pulling, even with a 14 to 31 tooth gear setup . so im trying to figure out two things now, how to improve take off torque since it is a slug off the get go. and how to improve efficiency. i drove 8 miles today at an average of 22 mph. and a top speed of 50 mph and i used about 22% of the battery, while im kind of impressed, thats alot of battery consumption. also the good news here is that the controller stayed nice and cool. the motor will absolutely need to have the water cooling hooked up , when i got home it was hot enough that i couldn't leave my hand on there for longer than 10 seconds. i wouldn't call that cooking, but it was definitely warm. both seats are in, and i am going to take some good photos tomorrow i hope. I managed to work on some small annoying details like wire management. i still haven't tied down the controller since im considering running a 96v controller on my buggy with my 48v motor. im looking at a 2010 sevcon controller thats 80 to 110 volts at 350 amps. if i can program it to limit voltage im sure it will not kill the motor but maybe it would fix my acceleration issue? im so proud of this little buggy, its becoming a mini neighborhood celebrity. i was already asked to give rides around the neighborhood and i did! so my two main things are improving efficiency and improving take off power.
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby falshami » Thu May 11, 2017 4:49 am

Here's some photos for you all!

http://imgur.com/a/vyPrS
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

Re: large road legal electric go kart build. need help!

Postby galderdi » Thu May 11, 2017 8:39 pm

Great pics. I particularly like the one at the Gas station. I guess you were there to thumb your nose at them "Here is one less customer for you suckers!!!!"

My understanding is that typical home grown EVs typically use around 320Whrs per mile. So I think you are well under that benchmark (probably because of the light weight).

I doesn't sound like the motor is getting overly hot. Hot to the hand doesn't equate to hot for a motor. So I think the cooling idea may be overkill. However it is always a welcome precaution so long as it doesn't add too much weight.

I can't think of any sensible ideas to improve your performance other than those you've suggested.

A less than sensible idea would be the addition of a clutch.... rev the thing with the clutch disengaged then drop the clutch and let the inertia get you moving.
I also considered a second smaller motor but with much lower gearing to get you going. But then when you get to the higher speeds the smaller motor would be over revving.

I think you are on the right track.
galderdi
1 kW
1 kW
 
Posts: 306
Joined: Tue Sep 08, 2015 8:17 pm

Re: large road legal electric go kart build. need help!

Postby Hillhater » Thu May 11, 2017 9:43 pm

falshami, did you ever find out what the gearing ratio is in that differential/final drive box ?
Or what rpms the motor runs up to ?
This forum owes its existence to Justin of ebikes.ca
Hillhater
100 GW
100 GW
 
Posts: 7958
Joined: Tue Aug 03, 2010 10:33 pm
Location: Sydney ..(Hilly part !) .. Australia/ Down under !

Re: large road legal electric go kart build. need help!

Postby Inwo » Thu May 11, 2017 9:48 pm

Nice looking bms. :)

Here is picture of possible pcb to parallel and connect bms-24 to any type of Volt module.
You in?

Ribbon board.gif
Ribbon board.gif (59.49 KiB) Viewed 291 times


Would like to rotate ribbon for cleaner routing module to module.
Which way are your parallel batteries mounted?
No sure you are getting my emails.
Last edited by Inwo on Thu May 11, 2017 9:50 pm, edited 1 time in total. View post history.
User avatar
Inwo
1 kW
1 kW
 
Posts: 330
Joined: Tue Dec 13, 2016 12:01 pm
Location: SE MN. USA

Re: large road legal electric go kart build. need help!

Postby fechter » Thu May 11, 2017 11:22 pm

There may be a setting in the controller software you can change to get a stronger takeoff. Something like soft-start parameter.

Getting the gearing right is super important. If you're geared too tall, the motor will be drawing too much current and efficiency will be low. Motors are much happier when geared lower.
"One test is worth a thousand opinions"
User avatar
fechter
100 GW
100 GW
 
Posts: 11299
Joined: Sun Dec 31, 2006 3:23 pm
Location: California Bay Area, USA

Re: large road legal electric go kart build. need help!

Postby falshami » Fri May 12, 2017 2:18 am

So I am using a golden motor controller. i am not sure if it is doing a soft start, if it is, id love to see that changed up and if you all have ideas where in the software to disable that id love that as well.


So i attempted a 5 to 1 gear ratio which gave me exciting acceleration and torque, potentially breaking the gear box if not careful. but netted a very very low speed of 18mph. and used very few amps. i tried a 2:1 ratio using an 18 tooth to 31 tooth and it got me around 41 mph, but god awful acceleration.. im using now a 14 to 31 tooth and so far its a nice balance of top speed of which ive hit 44-50 mph depending on the grade of the road and we have quite a hilly area that i live in. i think im going to settle on a 12 to 31 tooth system that should get me around 40 mph top speed and better taker off acceleration, and im hoping it doesnt draw so many amps? its odd because when i had a large sprocket it never really hit over 220 amps. same with a super high gear ration of 5:1 but my current setup will easily do over 300 amps sometimes. which confuses me

what gear ratio are you suggesting fechter?

haha INWO buddy yes! sorry it took so long to reply. i ADORE my BMS system, thanks to you! yes i am totally in for it as it would clean up my batteries and make things safer i believe. so lets do it, for a total of 4 batteries! by batteries are pretty much setup as a square just bare in mind i will in the future set them up for 96 volts, but leave them in 48v form for the bms and charging, that should be ok correct?

Galderdi, you are the only person to notice what i did there. of course i did that! i went in and bought water! im thinking the savings will be insane already from my 13 mile per gallon jeep commander and even my 22 mpg Chrysler crossfire.

im going to calculate my WHrs usage, i think i calculated a usage of 7.5 ah per mile which is ALOT, if i can get it closer to 5 i will be sitting really pretty!

i did actrually install a motor cooling system today i want to get that motor nice and cool , i may add a heat sink to the front since it may get warm in our arizona summers . weight of the cooling system was like 4 pounds

voltage seems to be my only way to increase speed and efficiency

tomorrow project will be to wire in my solar panels which should get me an extra 5 amps into the battery while driving and while parked which will be helpful, and thge panels weigh like 6 pounds

the clutch i cant figure out...we tried a cvt which just collossaly failed and was loud as hell... second motor may not be a terrible idea. i have a 5kw motor laying around i may sell with controller

update for today. i drove it for a 15 mile round trip and it did great minus the take offs. the cool part was i had around 50% maybe 60 % battery left meaning a theoretical 30 mile range? i was very excited. it was only ever bogged down at one point on one large hill, it was down to about 30 mph up the hill with a speed limit of 35 so some people weren't happy behind me but i was fine . all with my stereo and subwoofer blaring :D

this project is exciting and im hoping that a second rider wont kill my power.... all ideas are welcome!
falshami
100 W
100 W
 
Posts: 128
Joined: Wed Nov 13, 2013 1:43 am

PreviousNext

Return to Large EV General Discussion

Who is online

Users browsing this forum: No registered users and 1 guest