Prototype EV for race

[Solexelec]

Hello

my name is Sylvain
I'm live in France

I create and I'm developing EV for race competition
the EV is like a moped but the motor is placed on the front rear and traction was diectly onthe tyre.





The part cycle was in steel
the weight 70kg and with the pilot i arrived at 130kg ( 260lbs)

For the motor

battery pack: Kokam Lipo 7S 24v 200AH
controller: KLS-S 6035 350A peak and 150A cont.
motor 80100 350KV with pcb sensor hall 120°
I'm using demultiplication 1,07

theorie Vmax 71km/h

I have a race this sunday (6 hours race) like 24h du Mans

At the first time i drive with 60% current limit on the controller ( 210a) near the current peak motor)
result the wire burn!!!!!!

for the race i change motor and choose 40% current limit on the kelly ( 140a)

result no burn great news

motor temp 48°C
amp in use 110A during 3min after 1min under 86a
the current shut down when arrived at 60km/h

but i haven't good acceleration and on out of turn when i wan't to accelerate the motor accelerate slowly.

For more performance I have two idears
bigger motor because i work under 24v and i need more robust motor i need 6KW power that why i need 250a peak
and high speed motor 12000 rpm
i look about TP100 motor at 540Kv
and i looking about maytech motor D108 320KV

Can you have some data about this motors or experience
i don't find informations with search here

thanks for you help

and sorry for my english.

 

[Boulter EV]

Hello, welcome to the forum. What interesting machine! What is the race?

Is there a reason you're limited to 24v? The easiest thing to do might be to increase voltage and change the gear ratio? I'm sure if your motor is rated at 24v it'd be ok at 36 or even 48.....

 

[cheapcookie]

Yes I don't under stand are you limited in voltage somehow ?

 

[Solexelec]

Hello
i'm want to stay in 24v because i find some Kokam cell 200ah and for the race i need lot of energy for drive during 1h continue

i run this sunday 6h race we used three pack of 24v 200Ah and we finished 2nd Scratch it's amazing we are very happy and now we need to drive fast very faster...

I have two ideas to win 10 or 15kph
first rewind 80100 motor

second buy an TP100 motor

 

[Solexelec]

Cheapcookie you are in France me to. I live near Besançon.

 

[billvon]

Hello i'm want to stay in 24v because i find some Kokam cell 200ah and for the race i need lot of energy for drive during 1h continue

So put 2 in series.

i run this sunday 6h race we used three pack of 24v 200Ah and we finished 2nd Scratch it's amazing we are very happy and now we need to drive fast very faster...

You are likely going to have to change from friction to direct drive. Friction drives are inefficient and power-limited.

 

[Solexelec]

hi billvon
my battery pack weight 30kg if i build in serie..... 60kg
i can't put this on the EV...

 

[billvon]

hi billvon
my battery pack weight 30kg if i build in serie..... 60kg
i can't put this on the EV...

Then rewire for 48 volt. You will increase power (and speed) and decrease weight (and thus extend range.) Or change batteries. If you are serious about racing, "well, I have this really cheap . . . " is never a valid excuse.

Note that your batteries are giving you about 160 wh/kg. You can do much better. That means if you went to better batteries you could get more power with less weight. Using Lunacycle 52V packs, for example, you could get 52 volts, 120 amp hours (considerably more energy than you have now) for 27kg.

 

[cheapcookie]

Salut, il faut vraiment que tu changes la configuration de ta batterie : beaucoup trop d'énergie est perdue en chaleur à tirer des ampères.

Écoute, ce que nous te disons rearrange ta batterie en 12s.

Je ne sais pas quel genre de lithium tu as, mais 50v ça fonctionnerait beaucoup mieux.

Je te conseille FORTEMENT de regarder le contrôleur VESC, meilleur contrôleur sur le marché et coute seulement 100 euros en moyenne.

regarde aussi le toro beast 200a.

Pour la charge de batterie utilise un transfo AC>DC Meanwell, et des charge doctor balancer ou autre.

Me concernant je n'habite plus en Europe malheureusement.

A +



Hi, you really need to change the configuration of your battery: too much energy is lost in heat to pull amperes.

Listen to what we tell you rearranges your battery in 12s.

I do not know what kind of lithium you have, but 50v would work much better.

I strongly advise you to look at the VESC controller, the "best" controller on the market and only cost an average of 100 euros.

also look at the toro beast 200a controller.

For battery charging uses an AC transformer> DC Meanwell, and charge doctor balancer or other.

About me I no longer live in Europe unfortunately.

Bye

 

[liveforphysics]

Contrary to the assorted bad advice above, it's no penalty to be 24vdc, but you do need to understand how to make good low resistance joints and busing (meaning no-solder and only cold-forged crimp joints in the appropriate cross section conductor.

If I were building EV drivetrains today in the 2-5kW range, I would use 12vdc pack voltage.

Most Ebike's run pointlessly high voltage due to a misunderstanding of thinking it's needed or a good idea.

 

[jonescg]

Can you recommend a motor speed controller for 12 V and 150 amps?

 

[skeetab5780]

Can you recommend a motor speed controller for 12 V and 150 amps?

This is getting interesting!

 

[fechter]

Contrary to the assorted bad advice above, it's no penalty to be 24vdc, but you do need to understand how to make good low resistance joints and busing (meaning no-solder and only cold-forged crimp joints in the appropriate cross section conductor.

If I were building EV drivetrains today in the 2-5kW range, I would use 12vdc pack voltage.

Most Ebike's run pointlessly high voltage due to a misunderstanding of thinking it's needed or a good idea.

At 12v, the battery cables would need to be the size of a garden hose.

 

[zackclark70]

if your raceing get a cromotor v3 a good controller run 48 72 or 96v and you will have more power than you know what to do with

other option is a mid drive setup and you can get 12kw with 30kw peak with off the shelf parts without crazy money and effort but you will wish you had it strapped to a motobike frame

what are the rules you have to follow for this race ?

 

[liveforphysics]

Can you recommend a motor speed controller for 12 V and 150 amps?

Whats the application my friend? If it's something where power to weight is important and the duty cycle of full power is low, RC car controllers may work. If you are starting the motor turning under load I would go sensored.

https://www.google.com/search?q=1/5th+scale+brushless+ESC&safe=off&client=ms-android-sonymobile&sa=N&biw=360&bih=512&noj=1&tbs=vw:l,ss:44&tbm=shop&srpd=7568329522191891689&prds=num:1,of:1,epd:7568329522191891689&ved=0ahUKEwi-o63y9p3VAhWJjFQKHdt2BowQgjYIiAU

If it's for something with a high duty cycle or industrial or something I would run a Curtis fork lift controller or similar clones.

Contrary to the assorted bad advice above, it's no penalty to be 24vdc, but you do need to understand how to make good low resistance joints and busing (meaning no-solder and only cold-forged crimp joints in the appropriate cross section conductor.

If I were building EV drivetrains today in the 2-5kW range, I would use 12vdc pack voltage.

Most Ebike's run pointlessly high voltage due to a misunderstanding of thinking it's needed or a good idea.

At 12v, the battery cables would need to be the size of a garden hose.

Ehh, a few feet of 2awg is cheap and light enough for me when I think of the cost and failure modes of the BMS rats nest and components.

Many paths to make a great performance ebike.

 

[Boulter EV]

I'm guessing the reason you would need to increase battery mass to change voltage is because your cells are huge and you only have 1 in parallel.

@liveforphysics. Higher voltages nearly always means better efficiency and better power density. But to actually capitalise on this you need to have correct motor windings and gearing. You may be right that some ebikes would be fine on 12v but for anything bigger/faster you'll get a better machine with higher voltages.

 

[Solexelec]

hi
i used 7s lipo battery
i work with 3,7v 200Ah kokam cells
i can change for 10s but if i change for this configuration i need new charger under 36v, i think about this.

i looking about vesc end toro beast but for the race we need long time power. I'm a newbie on EV I try...

 

[Solexelec]

if your raceing get a cromotor v3 a good controller run 48 72 or 96v and you will have more power than you know what to do with

other option is a mid drive setup and you can get 12kw with 30kw peak with off the shelf parts without crazy money and effort but you will wish you had it strapped to a motobike frame

what are the rules you have to follow for this race ?

I can't used cromotor
The motor drives the wheel by means of a gear wheel

when i finished my holidays i make more picture

 

[liveforphysics]

I'm guessing the reason you would need to increase battery mass to change voltage is because your cells are huge and you only have 1 in parallel.

@liveforphysics. Higher voltages nearly always means better efficiency and better power density. But to actually capitalise on this you need to have correct motor windings and gearing. You may be right that some ebikes would be fine on 12v but for anything bigger/faster you'll get a better machine with higher voltages.

Time for you to start over learning the EV basics perhaps.

 

[SlowCo]

I can't used cromotor. The motor drives the wheel by means of a gear wheel. when i finished my holidays i make more picture

If you want to stay with the Solex principle of a friction drive on the front tire you could definitely use a Cromotor. Just machine the outer diameter of the Cromotor to have a more raw surface or glue sand(paper) to it. Leave the spoke flanges to center on the tire and let the Cromotor spin the tire directly. Make the geometry of the hinge/axle so that the motor will dig into the tire when spinning.
You will have a gear reduction of the Cromotor's outer diameter vs. the tire's outer diameter. So you should choose the winding of the motor and your battery voltage so that you can achieve the desired top speed. If you can keep the slippage to a minimum your front tire might even last one race... :wink:

 

[amberwolf]

You will have a gear reduction of the Cromotor's outer diameter vs. the tire's outer diameter.

Maybe I just too tired to think clearly, or maybe i misunderstand how the friction drive power/speed transfer works, but I'm not sure this is actually true, because the speed the Cromotor is at on the tire surface is the same speed it would be if it were rolling directly on the ground. Since the speed doesnt' change, the torque shouldn't either?

 

[SlowCo]

You will have a gear reduction of the Cromotor's outer diameter vs. the tire's outer diameter.

Maybe I just too tired to think clearly, or maybe i misunderstand how the friction drive power/speed transfer works, but I'm not sure this is actually true, because the speed the Cromotor is at on the tire surface is the same speed it would be if it were rolling directly on the ground. Since the speed doesnt' change, the torque shouldn't either?

You are correct if you compare running the outer diameter of the hubmotor directly on the ground vs. used as a friction drive to the tire (although on the ground it would roll on the outer diameter of the spoke flanges vs. the outer diameter of the magnet ring on the tire... :wink: ). I meant that there is a gearing difference when using the Cromotor mounted in the wheel as it normally would be (being a hub motor) vs. used as a friction drive on the tire.

 

[amberwolf]

OH! Sorry I misunderstood.

 

[SlowCo]

OH! Sorry I misunderstood.

I suspect you have forgotten more about building electric vehicles and electronics than I'll ever learn. So you're forgiven :wink:

 

[Solexelec]

hi
for the moment in the technical regulations, we are limited to a diameter of gear on the tire has 50mm.
but the idear to use a hubmotor was good.

To be efficient, it is necessary to have 10000 rpm to the shaft which drives the gear of 50mm
i don't find data about hubmotor 6 or more kw
i need rpm about a cromotor to make the good ratio to find the 10000rpm.
i continue to search and ask to constructor data. if you have something...