# lowest cost brushed controller route to high performance EV



## mjcrow (Jan 5, 2008)

Pioneer Conversions recently did a nice comparison of most of the "High End" controllers on the market, it can be found here http://pioneerconversions.com/pdf/ControllerComparison.pdf


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## Georgia Tech (Dec 5, 2008)

Modified "Open Source Controller"....Thats the hands down Biggest Power for you buck!!


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## adamj12b (May 4, 2009)

Georgia Tech said:


> Modified "Open Source Controller"....Thats the hands down Biggest Power for you buck!!


I second that, It just depends on what voltage you are planing on running. I have a version of the controller that I m putting together with 130A mosfets and 120A diodes. So deraiting each of the 10 pairs to 80A, I should be able to get 800 motor amps pretty easily.

-Adam


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## Georgia Tech (Dec 5, 2008)

adamj12b said:


> I second that, It just depends on what voltage you are planing on running. I have a version of the controller that I m putting together with 130A mosfets and 120A diodes. So deraiting each of the 10 pairs to 80A, I should be able to get 800 motor amps pretty easily.
> 
> -Adam


Yeah your talking the Revolt? Paul's controller?..Yeah from the reviews that thing is an absolute STUD!! I know I am going that route my self when I could ever get ready...


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## adamj12b (May 4, 2009)

Georgia Tech said:


> Yeah your talking the Revolt? Paul's controller?..Yeah from the reviews that thing is an absolute STUD!! I know I am going that route my self when I could ever get ready...


Yes its the Revolt, But my own design. I have shrunk the size of the controller to about 5.375 x 9 x 3.5. Its very well packed together with a stacked board for mounting the caps.

-Adam


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## Bowser330 (Jun 15, 2008)

Another thing to consider is the possibility of water cooling, not all brands can offer this...Zilla and Soliton do.... Additionally you should also take the track record of controllers into play as well...Zilla has long track record of quality...

You didnt add the controllers from Netgain the Warp-core controllers...They have comparable prices as well and a track record for stout motors..

All in all, its pretty tough to beat the torque from 2000A, in my opinion, if your batteries and motor(s) can take it, why the hell not! 
In a dual motor setup, series mode would push out 2000A to each motor at low speeds....


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## voicecoils (Jun 15, 2008)

mjcrow said:


> Pioneer Conversions recently did a nice comparison of most of the "High End" controllers on the market, it can be found here http://pioneerconversions.com/pdf/ControllerComparison.pdf


Thanks mjcrow, that's a helpful link.


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## voicecoils (Jun 15, 2008)

Georgia Tech said:


> Modified "Open Source Controller"....Thats the hands down Biggest Power for you buck!!


I wouldn't disagree, however there is a strong appeal in having the 'heart' of the EV drive reliable and 'just works'.

If a screw holding down a mosfet loosens and it can't shed heat and fails, you're stranded. I haven't looked at the Revolt design myself, but having a professionally designed and constructed controller may be the better option in many cases.

I'll add the Revolt to the list however, as others may want to tackle the DIY route.


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## voicecoils (Jun 15, 2008)

Bowser330 said:


> Another thing to consider is the possibility of water cooling, not all brands can offer this...Zilla and Soliton do.... Additionally you should also take the track record of controllers into play as well...Zilla has long track record of quality...
> 
> You didnt add the controllers from Netgain the Warp-core controllers...They have comparable prices as well and a track record for stout motors..
> 
> ...


Thanks for the comments. Water cooling is likely to be the only option for any of the present controllers to draw 1000A+ for extended lengths or repeatedly.

I'll look at the Warp-core. Thanks!


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## Georgia Tech (Dec 5, 2008)

voicecoils said:


> I wouldn't disagree, however there is a strong appeal in having the 'heart' of the EV drive reliable and 'just works'.
> 
> If a screw holding down a mosfet loosens and it can't shed heat and fails, you're stranded. I haven't looked at the Revolt design myself, but having a professionally designed and constructed controller may be the better option in many cases.
> 
> I'll add the Revolt to the list however, as others may want to tackle the DIY route.


 From what I read the Open source controller is pretty reliable from people who use it...the Word is, there is a 1000 amp version on the horizen that is evn more effiecent!!


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## voicecoils (Jun 15, 2008)

Georgia Tech said:


> From what I read the Open source controller is pretty reliable from people who use it...the Word is, there is a 1000 amp version on the horizen that is evn more effiecent!!


Thanks. The TO-247 package fets look nice.

Is there a list of users using the revolt? I had a look on EValbum.com and came up empty.


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## Georgia Tech (Dec 5, 2008)

Check this thread out here...

http://ecomodder.com/forum/showthread.php/paul-sabrinas-cheap-diy-144v-motor-controller-6404.html


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## EVComponents (Apr 20, 2009)

voicecoils said:


> Thanks for the comments. Water cooling is likely to be the only option for any of the present controllers to draw 1000A+ for extended lengths or repeatedly.


In reality, nobody needs 1,000 amps for an extended period of time. Otmar once told me that 600 amps continuous could power a bus at highway speeds.

For most people, 300 amps continuous is more than enough power. There are a number of controllers that can meet that standard. 

The only reason for the 1,000 amps or more is during your acceleration period, which is likely not very long. You will never have continuous acceleration for an extended period of time.

Look for a controller that will best handle the acceleration that your EV battery pack is designed for.

For a low voltage 750 amp controller, Synkromotive has a really good design. It should definitely be on the original list.


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## voicecoils (Jun 15, 2008)

EVComponents said:


> In reality, nobody needs 1,000 amps for an extended period of time. Otmar once told me that 600 amps continuous could power a bus at highway speeds.
> 
> For most people, 300 amps continuous is more than enough power. There are a number of controllers that can meet that standard.
> 
> ...


Synkromotive is:
$1612.50 / 109.2 kW = 14.77 $/kW
and from the limited perspective of cost / power ratio is not competitive with the some of the other options investigated.

This is just a desktop review of the options out there for a high powered DC EV. Repeated accelerations and hill climb races are 2 instances where the controllers would need to deliver large amounts of current and ideal do so efficiently or with effective cooling to avoid thermal failure.


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## Bowser330 (Jun 15, 2008)

"powering a bus at highway speeds" can be somewhat misleading because the bus's weight creates inertia for the bus to maintain that highway speed so the 600A only really needs to help it keep moving at highway speeds...trying to accelerate from 0mph up a hill (on-ramp type) would be tough with 600A...

For anyone looking for anywhere close to "stock" performance out of their conversion, there is no question that a 1000A controller is a necessity and there are several that can foot the bill that are available right now for purchase, the RaptorII, the netgain warp core, Soliton1 and of course the Zilla1K....


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## EVComponents (Apr 20, 2009)

Bowser330 said:


> "powering a bus at highway speeds" can be somewhat misleading because the bus's weight creates inertia for the bus to maintain that highway speed so the 600A only really needs to help it keep moving at highway speeds...trying to accelerate from 0mph up a hill (on-ramp type) would be tough with 600A...
> 
> For anyone looking for anywhere close to "stock" performance out of their conversion, there is no question that a 1000A controller is a necessity and there are several that can foot the bill that are available right now for purchase, the RaptorII, the netgain warp core, Soliton1 and of course the Zilla1K....


Bowser,
I agree that 1,000 amps is useful for acceleration. The post I was responding to was making the point that 1,000 amps for an extended period (all the time) is not needed. Most of the time we are driving with our inerta on the road. During most of your drive time how many amps are you using? Less than 200?


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## Qer (May 7, 2008)

EVComponents said:


> For most people, 300 amps continuous is more than enough power. There are a number of controllers that can meet that standard.


I guess that "enough power" is a very flexible term, but I do know that back when Dimitri was the only one driving a Soliton1-powered car and the Soliton1 he used were limited to 500 Amps top and had a very aggressive temperature cut back Dimitri was not satisfied. I still have a few of the logs, here's one example.










So, would 300 Amps be enough for most people? I don't know about most, but quite certainly it will be enough for some people. However, I do know for sure that it wasn't enough for Dimitri and his Protege5 (he made that perfectly clear to me and Tesseract  ) and he sure wasn't happy about doing 0-60 in snail speed (with ~350 Amps it took him about a minute to make it!), but of course it all depends on how, and where, you drive.

I do, indeed, agree that for most people 1kA continuous is probably more than enough (but then, some people WANT more than enough...) and if you're mainly driving in the city and rarely above 30 mph any shoebox can probably fulfil your needs while someone converting a sports car probably want it to perform accordingly. We all have our different expectations and demands and as well as one of my colleagues is quite happy with his Mini Cooper while I prefer my Grand Cherokee I expect DIY'ers and other EV-owners to have different preferences as well.

So, which one to choose and which technical specs are the important ones?

How long is a piece of string?


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## EVComponents (Apr 20, 2009)

From your data it looks like Dimitri would have been fine with a 750 amp controller like the Synkromotive at half the cost. They are selling the Synkromotive controller at $1,612. 

Of course I would like to see everyone using a High Voltage Zilla and paying $2,675. I am sure you want to sell everyone a High Voltage Soliton at $2,895 to $3,200.

But the reality is that most of our customers are buying a 1,000 amp Z1K-LV controller for $1,975. 

I am sure that people looking to save money are going to get a good quality product from either Synkromotive or Warp with a 750 amp controller. I think Warp is around $1,500 or $1600 for their 750 amp low voltage controller.


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## EVComponents (Apr 20, 2009)

voicecoils said:


> What's the lowest controller cost way to get there, assuming multiple controllers can be used if required? Here's what I've come up with:
> 
> 
> 
> ...


Here is more Zilla data for your chart:

*Zilla Z1K-LV*
Nominal = 72-156
Max = 208 (tested to 240 V at factory)

*Zilla Z1K-HV and Z2K-HV*
Nominal = 72-300
Max = 375

*Zilla Z1K-EHV and Z2K-EHV*
Nominal = 72-348
Max = 429


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## Qer (May 7, 2008)

EVComponents said:


> From your data it looks like Dimitri would have been fine with a 750 amp controller like the Synkromotive at half the cost. They are selling the Synkromotive controller at $1,612.


Indeed. There's even many converted cars that handles the daily commuting with a Curtis 1231C, but if all DIY:ers settled for the minimum controller that got the job done, we'd both be in trouble. 



EVComponents said:


> Of course I would like to see everyone using a High Voltage Zilla and paying $2,675. I am sure you want to sell everyone a High Voltage Soliton at $2,895 to $3,200.


When we started on the Soliton1-project we picked a set of IGBTs rated for 600 Volt. This is the typical limit for most industrial power electronics and because of sheer production volumes this means that there's not much cost to shave off by lowering top Voltage. So in essence what you pay for isn't really the Voltage limit but the ability to provide continuous current.

It's true that as long as you mainly drive on flat roads you only need high current when accelerating, however if you're going uphill current will roughly double for every 5% increase in incline. That's when continuous rating really will be important, because the average driver (the kind that doesn't want to tinker but just get to work and back) won't care why the car slows down, they'll just be upset that it is.

We're fully aware that some people won't be prepared to pay for this luxury, but then the Soliton isn't really aimed at them. We also know, empirically, that some people DO find the Soliton worth the cost and thus obviously there's a market for the Soliton.


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## voicecoils (Jun 15, 2008)

EVComponents said:


> Here is more Zilla data for your chart:
> 
> *Zilla Z1K-LV*
> Nominal = 72-156
> ...


Thanks, I'll update the spreadsheet and repost once I'm back on the computer that has the file on it.

For clarification, at the max voltage for each listed can the controller actually output the full current rating?

For example, if an extremely high C-rate pack is connected to a Z2K-EHV and can deliver 2000A at 400V, can the controller output 800kW on the motor side?

The EVComponents site says 640kW max in the spec page....


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## EVComponents (Apr 20, 2009)

voicecoils said:


> For clarification, at the max voltage for each listed can the controller actually output the full current rating?
> 
> For example, if an extremely high C-rate pack is connected to a Z2K-EHV and can deliver 2000A at 400V, can the controller output 800kW on the motor side?
> 
> The EVComponents site says 640kW max in the spec page....


This is where I would follow the specs. And this is peak, and in no way guarantees any sustained amount of time. What you need to know is that even with assuming lower efficiency and only 380volts. There is potentially 815 horsepower.


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## octagondd (Jan 27, 2010)

I am glad I read this thread. I am a good example of the problem discussed here. I am planning a light weight conversion for a 30 mile freeway commute. The only issue is, on the way home I have a 2 mile hill at 3% grade. This requires about 270 motor amps to maintain 70mph if I am reading the ev calculator correctly. (I live in L.A. and that is about the minimum speed here) So I need a controller that can do at least 300 amps for those two minutes. Now, what if I stop at the market at the bottom of the hill? Now I need to accelerate to freeway speed while climbing a 3% grade and it will take me about 3-4 minutes to get to the top. What kind of motor amps do I need now? I am guessing I am the exception rather than the rule, but it looks like I may need a 400a continuous controller and 4C rated 100AH LFPs to make it happen. Does this sound about right?


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## Qer (May 7, 2008)

octagondd said:


> The only issue is, on the way home I have a 2 mile hill at 3% grade. This requires about 270 motor amps to maintain 70mph if I am reading the ev calculator correctly.


Hmm. I think you're confusing motor- and battery amps. 270 Amps @ 3% incline sounds extremely low. The (theoretical) current multiplication per percent inclination is:

1% = 1.279
2% = 1.561
3% = 1.839
4% = 2.118
5% = 2.400 (steepest standard grade in the US)
6% = 2.679
7% = 2.957

So if you need 270 Amps @ 3% it means that you'd only need about 150 Amps to keep 70 mph on flat ground. That sounds unreasonably low unless you're talking battery current rather than motor current.



octagondd said:


> it looks like I may need a 400a continuous controller and 4C rated 100AH LFPs to make it happen.


And this is why I think you mean battery current when you're saying motor current. 

If, above, you mean battery current this makes more sense, but motor current is equal to or greater than battery current. As long as PWM is lower than 100% (ie not fully on) battery current will be less than the motor current, like this:

Ibattery = Imotor * D

where D is pulse duration between 0-1 (ie 0-100%) so if Imotor is 400 Amps and D is 0.5 (50% pulse width) your battery current is:

Ibattery = Imotor * D = 400 * 0.5 = 200 Ampere.

Now, since controllers are rated for motor current odds are that if you're talking battery current those 400 continuous motor Amps might not be sufficient for you...


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## octagondd (Jan 27, 2010)

Qer - I have been using the ev calculator on evconvert.com so that is where my numbers came from. It lists motor amps and battery amps, but if the formulas aren't correct then I should make sure to do the math myself first.

My car will be about 2250 lbs with me in it, so on flat ground in 4th gear it says I need 168 motor amps and 120 battery amps to maintain 70mph. If that is correct and I use your multipliers then I would need about 310 motor amps and 220 battery amps to maintain 70mph up the hill.

I am very new to this so if my rationale doesn't make sense or you think the ev calculator is off, please let me know. I want to make sure I get the right product the first time.


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## CroDriver (Jan 8, 2009)

voicecoils said:


> Thanks, I'll update the spreadsheet and repost once I'm back on the computer that has the file on it.
> 
> For clarification, at the max voltage for each listed can the controller actually output the full current rating?
> 
> ...


It is absolutely impossible to have 400V at 2000 Amp in the real world.

I'm building a oversized pack with the best cells available. It will be 410V when fully charged / 370V nominal / 180 Ah. The cells are rated at 20C continuous and 30C peak (best cells "available" AFAIK).

From my single cell testing I believe that my pack will sag to 300V at full throttle (3600 Amp for two controllers). So that will be 540 kW on the BATTERY SIDE! DC motors are very inefficient at these overloads so I guess that I will have 300-350 kW on the motor shaft per motor / controller.

I think that this is the absolute maximum that is possible with todays technology. 

No one can tell now if all components will behave as planned.


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## voicecoils (Jun 15, 2008)

CroDriver said:


> It is absolutely impossible to have 400V at 2000 Amp in the real world.
> 
> I'm building a oversized pack with the best cells available. It will be 410V when fully charged / 370V nominal / 180 Ah. The cells are rated at 20C continuous and 30C peak (best cells "available" AFAIK).
> 
> ...


The cells you're getting from cell_man are undoubtedly an excellent choice.

However, they're simply not the highest C rate cells money can buy. While they are rated 30C continuous, 40C pulse, you can buy 45C continuous, 90C pulse lithium polymer cells from Enerland (a division of A123):

http://www.enerland.com/product/product_list2_f.asp?cat=XF&scate=4000mAh~

They are small capacity and expensive, but they have higher power density then the cells you'll be using. For the same weight, they'll deliver more power...2.25 times more power then the equivalent cell_man cells.

If I was in your position though, I'd be sticking with the same choice you've made though.


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## Qer (May 7, 2008)

octagondd said:


> Qer - I have been using the ev calculator on evconvert.com so that is where my numbers came from. It lists motor amps and battery amps, but if the formulas aren't correct then I should make sure to do the math myself first.


I'm sorry, I can't really help you there, but from what we've seen in logs from the Soliton your numbers sounds a bit optimistic. Of course, it's quite possible I'm wrong since I know too little about your build, but considering the weight etc I'd say it'll be tough to keep the current that low.


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## octagondd (Jan 27, 2010)

Qer said:


> I'm sorry, I can't really help you there, but from what we've seen in logs from the Soliton your numbers sounds a bit optimistic. Of course, it's quite possible I'm wrong since I know too little about your build, but considering the weight etc I'd say it'll be tough to keep the current that low.


Thanks for the help. It is quite possible that the ev calculator formula is not correct, a default value is wrong, or I have entered the wrong data somewhere. I will look into it some more. I am inclined to believe you more than what I know since you are actually involved with a controller.


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## EVComponents (Apr 20, 2009)

voicecoils said:


>


You might want to update the chart. 
Effective February 1st, the new pricing for Zilla Z2K controllers is as follows:

Z2K-HV = $4,175 
Z2K-EHV = $4,575 

We have lowered the prices by $500 on each of them

http://www.evcomponents.com/SearchResults.asp?Cat=37


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## ngcontrols (Nov 4, 2009)

Bowser330 said:


> Additionally you should also take the track record of controllers into play as well...Zilla has long track record of quality...


This is indeed a valuable factor. I don't think the Zilla needs any additional endorsements, but it certainly is a good product.



Bowser330 said:


> You didnt add the controllers from Netgain the Warp-core controllers...They have comparable prices as well and a track record for stout motors..


Safety, quality, power, and simplicity are some of the main areas of focus with this controller. I've said it before, but this is *the* time for EV enthusiasts! There are OPTIONS! Prices are coming down, availability is going up. A 1000A, 160V WarP-Drive controller order was shipped within 24 hours of receipt the order this week! I'm not sure I've seen any high-power, high feature controller orders ship that fast in the last 5 years!

BTW, quick correction ... it's "WarP-Drive" not "WarP-Core". The latter was a now defunct early product line not designed by NetGain.


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## maxvtol (Nov 11, 2009)

Qer said:


> ... but motor current is equal to or greater than battery current. As long as PWM is lower than 100% (ie not fully on) battery current will be less than the motor current, like this:
> 
> Ibattery = Imotor * D
> 
> ...


Just trying to understand how controllers function.

So if you stomp the pedal, and the motor is at low or 0 rpm, will the D be 1 and thus the motor amps be the same as battery amps, or will the controller sense a low or 0 rpm and supply higher amps to give greater torque?

And do all controllers act this same way?


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## ngcontrols (Nov 4, 2009)

maxvtol said:


> So if you stomp the pedal, and the motor is at low or 0 rpm, will the D be 1 and thus the motor amps be the same as battery amps, or will the controller sense a low or 0 rpm and supply higher amps to give greater torque?
> 
> And do all controllers act this same way?


Speaking specifically about series-wound motors (others might behave the same), the motor will attempt to spin at a certain RPM for a given voltage. Apply 12V with no load on the motor, and it will spin at, say, 500RPM. Now start applying a load, which will act to slow the motor down. The motor will start drawing more current to attempt to maintain the desired RPM for the voltage being applied.

At low RPM's, as you start applying voltage (increasing duty cycle), the current draw will begin to increase. The current draw will depend on the voltage being applied. If you mash on the pedal, duty cycle will increase rapidly (until the controller goes into current limit). For the (usually brief) period that the duty cycle is at 100%, battery current and motor current will be the same.

You'll see this behavior in any pulse width modulated controller.

-Ryan


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