# Better fans for the Soliton Jr?



## skooler (Mar 26, 2011)

lowcrawler said:


> The small teeny fans on the soliton jr are not only relatively loud (relatively, remember) but they don't actually seem to cool all that great. I can get it to 'high temp' on air with only 1 or 2 runs to 30mph in my bug. It does eventually drop in temp decently quick... but I'm amazed at how quickly it gets up there.
> 
> Are there any reasonable ways to replace the fans with larger ones? Say bigger, but quieter, 120mm ones?


I'm not saying this is a good idea (perhaps water cooling is the next logical step?)....

Take a look at delta fans. They make them for servers... I have some 40mm delta fans that push out 40cfm!


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## somanywelps (Jan 25, 2012)

I like my 120mm panaflo's. Then again there might be something better made in the last 6 years...


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## glaurung (Nov 11, 2009)

If i remember right Soliton likes to have its internal parts cool. If you plan to use it for a long time it is advised to use water cooling. I have not had it go to performance setting because of heat even once since i installed liquid cooling to my 5200lbs Range Rover.
Harri


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## lowcrawler (Jun 27, 2011)

It does not appear there are good mounting options... or even reasonable non-destructive connection options...no?


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## Tesseract (Sep 27, 2008)

lowcrawler said:


> ... I can get it to 'high temp' on air with only 1 or 2 runs to 30mph in my bug. It does eventually drop in temp decently quick... but I'm amazed at how quickly it gets up there....


The Jr's temperature sensor is inside its IGBT module so it responds very quickly to changes in motor current. The actual temperature derating schedule is on p29 of the manual but you can estimate the total losses in the controller at about 2W for every amp of motor current. 

As for using higher volume fans, the biggest reduction in effective thermal resistance (RTHETA) comes from the first few CFM of airflow because RTHETA vs. CFM is approximately a square law function. To make matters worse it requires 8x more power to double the CFM from a fan so that's a cubic law function. Hence, if you find that the built-in fans are not sufficient for your application then you should proceed directly to liquid cooling, which is kind of why we bother to drill the holes for such in the first place...


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## lowcrawler (Jun 27, 2011)

That makes sense. Gotta love having the manufacturer themselves help you on questions about their products!

To be perfectly honest, I was mostly looking for a way to make them quieter. Coming from a computer background that has done a bit with theromodynamics and fluid dynamics, I know larger fans can move just as much (or more) air with much less noise. When I'm driving I don't notice the noise really (my 40 year old tranny makes way more)... but when I start the car it would be nice to not have the rush of noise from full-on little teeny fans.

I did the water-cooling thing in a computer before... it was a pain in that environment. I can only imagine what a pain it would be in a car that has to live in 100F and -35F weather while bouncing around on bumpy roads. One of the big selling points for the Evnetics products was the air-cooling. Unless it proves to overheat in normal use (which I very much doubt) I'll stick with air. 

(though that makes me wonder, should I seal the liquid cooling ports so road grime doesn't get in there?


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## Tesseract (Sep 27, 2008)

lowcrawler said:


> ...but when I start the car it would be nice to not have the rush of noise from full-on little teeny fans.


I just pointed my dB meter straight at the fans on a Jr here in my lab and got a reading of 51dB at 1'. That's pretty damn quiet by any standard.

Perhaps the sound is being conducted to the vehicle cabin?

As for whether you should plug the coolant ports up or not, my suggestion is and always will be that you use them for their intended purpose.

And as for normal use... who knows what that is!?! Does your vehicle weigh 2000# or 3500#? Do you drive on the highway at all? Hilly terrain or mostly flat? Do you have a bit of a lead-foot, or are you more of a hypermiler?


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## lowcrawler (Jun 27, 2011)

Tesseract said:


> I just pointed my dB meter straight at the fans on a Jr here in my lab and got a reading of 51dB at 1'. That's pretty damn quiet by any standard.


Compared to a good 120mm fan, it's loud. I mean no offense... just the way it is. Like I said, the only time it's a bother is when I start it up and they go racing loud during the precharge...



> As for whether you should plug the coolant ports up or not, my suggestion is and always will be that you use them for their intended purpose.


Well, right -- if I want to water cool, I would. But the Soliton Jr is clearly sold as a controller that can go air-only. So until it proves that's too hard on the device, I'd like to do that.
I guess my question was more -- if one isn't going to water-cool, but may in the future... would it make sense to plug those holes in order to protect the inner channels... or would you suspect it's not going to matter.



> And as for normal use... who knows what that is!?! Does your vehicle weigh 2000# or 3500#? Do you drive on the highway at all? Hilly terrain or mostly flat? Do you have a bit of a lead-foot, or are you more of a hypermiler?


haha. Understandable.
It's a converted bug, probably weight in at about 2000#, I'm more of a hypermiler, and the biggest grade I ever drive on are entrance and off ramps. Most of the driving is flat... though it does include freeway driving.
I'm also in MN where the average temperature in January is -14C... and it routinely gets to -34C so most of the year I'll be more concerned about heat than cooling. 
From initial logs, it doesn't look like I'll need to worry... if I do, I'll deal with things then.


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## ElectriCar (Jun 15, 2008)

Not sure about where you are but in the southern US, I'd plug them up. Dirt daubers love to lay eggs in such holes and pack them with mud, completely sealing them up! 

Don't know about the Soliton products but when I had problems overheating like that with a Curtis, I was told to keep the RPM higher than you normally would in a gas powered car due to the back EMF I believe that is more prominent as the RPM builds. Keeping the car one gear lower seemed to help.


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## Qer (May 7, 2008)

lowcrawler said:


> Like I said, the only time it's a bother is when I start it up and they go racing loud during the precharge...


It's by design. The idea (my idea, blame me) is that that way you can easily verify that they work. Look at the controller, ask someone to activate ignition and see that both fans spin as they should. Much easier way to verify that they work than getting a blow torch and heat the controller until the fans kick in! 

And, well, it's like 2-3 seconds of fan noise? It can't be that horrible to endure that, can it...?

(And just to clarify, that blow torch comment was a joke. Of course. Don't try this at home, etc...)


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## ElectriCar (Jun 15, 2008)

Thanks for that feature Q. It's a good idea to know they're running. BTW You do use ball bearing fans correct?


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## Tesseract (Sep 27, 2008)

ElectriCar said:


> Thanks for that feature Q. It's a good idea to know they're running. BTW You do use ball bearing fans correct?


Qer wouldn't know what kind of fans we use but, no, they have sleeve bearings. There is a ball-bearing version of the fan which costs twice as much and last twice as long, but given how long each day an EV motor controller is used it hardly seems relevant whether the fans last 30,000 hours or 60,000 hours...


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## Qer (May 7, 2008)

ElectriCar said:


> Thanks for that feature Q. It's a good idea to know they're running. BTW You do use ball bearing fans correct?


Der.... They're, like, fans! Two of them! Colored black and run on 12 Volt. Both of them!

Did I mention there's two of them?


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## ElectriCar (Jun 15, 2008)

If they're rated for 30K hours then they can be plastic bearings, which can easily be replaced in a few years.


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## EVfun (Mar 14, 2010)

lowcrawler said:


> I can get it to 'high temp' on air with only 1 or 2 runs to 30mph in my bug. It does eventually drop in temp decently quick... but I'm amazed at how quickly it gets up there.


Can you share your controller settings, pack voltage and driving conditions? I've been eyeing the Jr. but would certainly want to run it air cooled. The ports aren't conveniently placed for a thermosyphon system. 

I had to install passive water cooling on the 1000 amp Zilla to keep it from complaining about heat after about 15 miles. Of course, they have no provision for air cooling so it was expected. My Buggy only weighs about 1200 lb. and runs about 200 watt hours per mile city, 300 watt hours per mile freeway. I am limited to 360 battery amps, 720 motor amps, to avoid abusing my 38 cell pack of 60 amp hour TS cells.


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## ElectriCar (Jun 15, 2008)

I'm surprised we didn't get an answer about the motor RPM and whether it affects heat build up or not.


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## Tesseract (Sep 27, 2008)

ElectriCar said:


> I'm surprised we didn't get an answer about the motor RPM and whether it affects heat build up or not.


Me too. Wait, what was the question, who asked it and to whom was it addressed?


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## ElectriCar (Jun 15, 2008)

ElectriCar said:


> ...Don't know about the Soliton products but when I had problems overheating like that with a Curtis, I was told to keep the RPM higher than you normally would in a gas powered car due to the back EMF I believe that is more prominent as the RPM builds. Keeping the car one gear lower seemed to help.


Right here. Wasn't a question I suppose.

They told me higher RPM's would make it run cooler, ie not to drive at a stady 1500rpm but 3000 or above or such. I don't like high rpm, speed kills bearings!


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## Qer (May 7, 2008)

ElectriCar said:


> They told me higher RPM's would make it run cooler, ie not to drive at a stady 1500rpm but 3000 or above or such.


Ah. To keep a certain speed at a certain slope and with a certain air resistance you need the power of P. P is RPM*Torque, RPM is (more or less) proportional to back EMF and Torque is (also more or less) proportional to current so:

P = RPM*Torque or U*I

If you increase RPM from 1500 to 3000 back EMF will double (well, let's just pretend the world is perfect, ok?  ) and for the same power current will be halved as a result.

If we say the voltage drop over the controller is Ud (which, again, requires the world to be perfect, it increases with I and things are a lot more complicated than this, but, eh, theory and perfect world again...  ) it means that the heat generated in the controller (let's call it Pl for losses) drops from:

Pl = Ud * I

to:

Pl = Ud * I/2

Which means that the heat generated in the controller gets halved and the controller runs cooler. Same thing goes for the motor too since the losses in the motor increases (by the power of two) with current.

In reality this is very simplified since there's a lot of other variables messing things up, but the thumb of rule that higher RPM means higher motor voltage which means lower current and less losses still holds. That, in turn, means that both controller and motor runs cooler if you change gear to get higher RPM.


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## ElectriCar (Jun 15, 2008)

Other than the confusing formulas, excellent!


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## Tesseract (Sep 27, 2008)

ElectriCar said:


> Right here. Wasn't a question I suppose.
> 
> They told me higher RPM's would make it run cooler, ie not to drive at a stady 1500rpm but 3000 or above or such. I don't like high rpm, speed kills bearings!


Oh, I thought you were just doing some off-topic musing, not specifically asking me a question.

At any rate, Qer already covered the obvious bit, which is that for the same amount of output power, a motor spinning at twice the RPM is going to be delivering half the torque and therefore will require half the amperage, and the amount of heat produced by the controller is mostly proportional to the amperage.

However, the less-obvious bit - ie, why a Curtis might be happier if the motor RPM is kept as high as possible - is because they use MOSFETs which have a purely ohmic on characteristic, and therefore usually exhibit a much lower voltage drop than the freewheeling diodes. Running the motor at low rpm requires a relatively low voltage from the controller so the switch stays on for a minor fraction of each cycle while the freewheeling diode conducts for the rest of each cycle. If the voltage drop across the FWD at a given current is a lot higher than that of the MOSFET at the same current, then the FWD will produce more heat; even more so if it is conducting for a majority of each cycle.

The Soliton controllers use IGBTs, however, which have a voltage drop when on that is roughly similar to that of a diode, and the amperage rating of both the IGBTs and the freewheeling diodes are roughly equal, too, so our controllers aren't much going to care what speed/torque loading you run your motor at. 

Note that bearings might hate being run at too high a speed, but the windings in the motor also hate being run at too high a current, so you don't want to go too extreme in either direction.


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## somanywelps (Jan 25, 2012)

What should you do about RPMs if you have an IGBT based controller and a forced air cooled motor so RPMs don't affect cooling?


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## Qer (May 7, 2008)

somanywelps said:


> What should you do about RPMs if you have an IGBT based controller and a forced air cooled motor so RPMs don't affect cooling?


Still keep the RPM high since the biggest losses will be in the motor. The power losses in the motor is:

P = I^2 * R

where R is the internal resistance of the motor (typically a few tens of mOhm). Since R is (more or less) a constant it means that if current is doubled the losses in the motor is quadrupled.

SImply put, cruising at a certain MPH with the motor at a higher RPM will give you more miles out of the pack than if you run it at a lower RPM. Exactly how big the difference will be will depend on a lot of factors (and at a certain level the losses in the motor will slowly start to become irrelevant compared to air resistance etc) but it's probably a good idea to try to keep the RPMs in the upper half of the safe register for a motor when cruising.


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## lowcrawler (Jun 27, 2011)

EVfun said:


> Can you share your controller settings, pack voltage and driving conditions? I've been eyeing the Jr. but would certainly want to run it air cooled.


I'm not at the car right now so I don't have the controller settings ...but off the top of my head...

154v nom, 100ah lithium pack. Limited to 400 battery amps, 130 no-load volts and 120 'loaded volts'... right now.

The run in question resulted after a few 'spirited' burst and then 0-35 full throttle run in 2nd gear (which I don't have the logs for so I don't know if I hit temp there, but I coasted/braked long enough that the control temp got back down to 29.2C (and falling) at the start of logging for the run in question ...). 
The run where I have logs (graph attached below) of High Controller Temp warnings was a full throttle run in 3rd gear from 0-30 (maybe 35ish) mph. Motor C (Amps) got to around 575 during the acceleration and it took, I dunno, 6-8 seconds?

The following graph shows motor C and Temp ... it is a full-throttle run to 30ish-mph, a bit of a coast and a bump just for fun, then a speed up to 35mph, then maintaining 35... then a speed up to 40, then maintaining 40... then a speed up to 45 and some maintaining 45... then coast/brake to stop. The ground wasn't perfectly flat, but it wasn't particularly hilly. (thus why maintaining 45 actually took less juice than maintaining 40)...

It seems that the the subsequent 300A draws resulted in temp upturns, but while doing 'speed maintenance' of around 75-100A the controller temps were well controlled (coming down quite quickly, in fact) with just air. Ambient was around 70-75F. (I forget exactly)

Once my charger gets back and I can take it out I can provide some further logs if you desire...


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## Qer (May 7, 2008)

You don't happen to run Soliton software version 1.4, do you?


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## PhantomPholly (Aug 20, 2008)

I've just lost 5 minutes of my life I can't recover reading this thread - why all of the angst around fan noise, and why is it such a big leap to move to liquid cooling? 

The controller comes with computer fans. The answer to "making it quiet" with computers is to move to liquid cooling. The manufacturer of the controller recommends it, and provides the ports so mods are not necessary. Radiators and tubing are cheap, and most cars already come with a good mounting location...

What's so hard about this?


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## lowcrawler (Jun 27, 2011)

Qer said:


> You don't happen to run Soliton software version 1.4, do you?


Nope, 1.5.1... which as far as I know is the most recent. Why do you ask?


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## lowcrawler (Jun 27, 2011)

PhantomPholly said:


> I've just lost 5 minutes of my life I can't recover reading this thread


No one forced anything and the thread was clearly labeled. 



> why all of the angst around fan noise


 One of the fun things about my EV is that it's silent (well, until it moves .. heh). It's a small thing, but hey -- what's the harm in asking? I think it generated some decent discussion. (even if I didn't get the answer I wanted)



> and why is it such a big leap to move to liquid cooling?


 Added hardware, added complication, etc. It's not a huge leap, but if' it's not needed (which is one of the large selling points of this particular controller), why would I?



> The controller comes with computer fans. The answer to "making it quiet" with computers is to move to liquid cooling.


 Or getting bigger, slower-moving fans. A 120mm panflow is WAY quieter than a 40mm buzz-saw.
I've only water-cooled one computer... and it was a huge pain in the butt compared to just getting some big nice fans. The only reason I ended up doing it was because I wanted heat dissipation levels that air couldn't handle.


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## PhantomPholly (Aug 20, 2008)

lowcrawler said:


> No one forced anything and the thread was clearly labeled.


Yep. That was sar-chasm. I suppose I should have clearly labeled it... 



> One of the fun things about my EV is that it's silent (well, until it moves .. heh). It's a small thing, but hey -- what's the harm in asking? I think it generated some decent discussion. (even if I didn't get the answer I wanted)


No reason at all, other than it seemed like after the first page or so it was beating a dead horse.



> Added hardware, added complication, etc. It's not a huge leap, but if' it's not needed (which is one of the large selling points of this particular controller), why would I?
> 
> Or getting bigger, slower-moving fans. A 120mm panflow is WAY quieter than a 40mm buzz-saw.
> I've only water-cooled one computer... and it was a huge pain in the butt compared to just getting some big nice fans. The only reason I ended up doing it was because I wanted heat dissipation levels that air couldn't handle.


I've gone water cooling on my gaming rig once too. My point was simply that we're not working inside a tiny case where the water will spill on your computer chips - we're working in a car with lots of room and where you can arrange the water lines so that a leak just goes overboard. We're also not talking about retrofitting a cooling solution to a chip not designed to be so cooled - they've done the work for you.

I know more about air cooling than I ever wanted to know, thanks to my flying hobby. It's a PITA to get small improvements, and generally requires carefully designed cowlings. The time and energy you would need to invest into getting a reasonable gain over the "stock solution" (say, a 20% cooling improvement, which doesn't sound like it will make that much difference to you) is enormous and frustrating.

Do the water cooling. Be cool, be happy...


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## DIYguy (Sep 18, 2008)

I've had a soliton1 for a few years now. I was one of the early buyers. Best thing I ever did with it was install the water cooling. It was cutting power and I didn't really realize it. After water cooling, it is always right there when I want it... 

Now I have a Shiva. It is getting water cooling before it gets power.


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## ElectriCar (Jun 15, 2008)

If it can run dry, I'd want to run it dry. $$$ IS a factor for some more than others. JMO.

I've been trying to get a 1 for about 3 weeks now and well when I get it I plan to try it dry as well. I know what it's rated for and what I need is far less so we shall see. 

Personally, I think a cowl induction hood ducted to it would be most helpful...and nice looking too!


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## DIYguy (Sep 18, 2008)

ElectriCar said:


> If it can run dry, I'd want to run it dry. $$$ IS a factor for some more than others. JMO.
> 
> I've been trying to get a 1 for about 3 weeks now and well when I get it I plan to try it dry as well. I know what it's rated for and what I need is far less so we shall see.
> 
> Personally, I think a cowl induction hood ducted to it would be most helpful...and nice looking too!


OK. 
I have a truck full of lithium. U have a truck full of lithium. I have (had) a Soliton1. You have (getting) a Soliton1. I have (had) a 9" motor. You have a 9" motor. (I think??). Just sayin. . . I been there. Done that. Put the water to it. It needs it. It will last longer, run cooler, be happier... and so will you cause it will give u full power when u want it. Or don't.... up to you. 

BTW, I was told the same thing... but I'm stubborn, so I didn't do it. . . until later (when it was my idea) lmao


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## fb_bf (Jul 6, 2011)

I read the release notes for the 1.5.1 software, and it said that it wouldn't report a high temperature condition until it saw 80, or was it 90 degC for the Soliton Jr.. It used to report it at 50C. I know because I was seeing overtemp warnings with the 1.4.1 code, and switched to water cooling to get around that. Have you been seeing overtemp reported with the 1.5.1 software?


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## ElectriCar (Jun 15, 2008)

DIYguy said:


> OK.
> I have a truck full of lithium. U have a truck full of lithium. I have (had) a Soliton1. You have (getting) a Soliton1. I have (had) a 9" motor. You have a 9" motor. (I think??). Just sayin. . . I been there. Done that. Put the water to it. It needs it. It will last longer, run cooler, be happier... and so will you cause it will give u full power when u want it. Or don't.... up to you.
> 
> BTW, I was told the same thing... but I'm stubborn, so I didn't do it. . . until later (when it was my idea) lmao


Dang it boy! I know what you mean. And you know I'll have to try it. No, I don't want it to overheat and it's much warmer at 35N latitude than where you are in the summer but I'll see. Plus I'm wanting to the the AC going, adding even more heat under the hood...


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## lowcrawler (Jun 27, 2011)

fb_bf said:


> Have you been seeing overtemp reported with the 1.5.1 software?


I did on the run I posted a graph for and that never got near 80 or 90.

I'll double-check I'm on 1.5.1 when I get home, but I just had it in to EVnetics last week and I'm pretty sure it came back with the 1.5.1 on it.


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## EVfun (Mar 14, 2010)

lowcrawler said:


> I'm not at the car right now so I don't have the controller settings ...but off the top of my head...
> 
> 154v nom, 100ah lithium pack. Limited to 400 battery amps, 130 no-load volts and 120 'loaded volts'... right now.
> 
> ...


Thank you, there is quite a bit of information there. It seems that without water cooling you may never reach 600 motor amps on a summer day. Even 300 amps seems to increase the temperature pretty quickly. It was a bit of an on/off session, and so hard to figure out what it can do air cooled while staying under 45C when starting out at 30C. It does look like needs water cooling.


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## lowcrawler (Jun 27, 2011)

EVfun said:


> It was a bit of an on/off session, and so hard to figure out what it can do air cooled while staying under 45C when starting out at 30C. It does look like needs water cooling.


I should have some time next week to do further testing with some longer sustained speeds. I'll do so and get back to you here...


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## lowcrawler (Jun 27, 2011)

Took a while... but here is a log of a ~10 mile mixed-use round trip with an ambient temp of about 65 and very sunny (so the roads were warmer).

The driving consisted of about 2.5 miles on a stop-and-go 30mph road, then about 1.5 miles on 60mph freeway (the first major temp spike to 70C is from me jamming on it a the onramp), then about 1 mile on a 30mph road to my destination. (you can see the temps drop straight down while the car was off)
On the way home I took a (relatively hilly) 50mph highway with a couple occasional stop lights and then the last mile is 30mph roads back to my house.

As you can see, the temps never broke 75C... and came down really quickly when 'stopped'.

I'll have to see what a longer sustained drive on the freeway does to it. I've got a 4mile 65mph freeway drive to do in a few hours. I'll see if I can muster the energy to log it.


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## lowcrawler (Jun 27, 2011)

I mentioned I'd come back after doing a bit more of a real life highway test using the Soliton Jr on air.

Good thing is: The derating works. 

The following is a graph of my requested amps (Thrl), delivered amps (motorC), Temp and Pack Volts....

This is actually a snippet of a longer run, so the controller and motor body were already quite warm at the start of this (having just done about 6 miles of other mixed driving). The ambient temp is about 85F (ie: quite warm) and I'm sure the temps on the pavement are much higher given it was a nearly cloudless day. I kept it at a pretty steady 60mph on the freeway until the derating forced me to slow to about 53ish at the worst part of the hill/derating combo.

I've labeled aspects of the graph showing my acceleration on the onramp in 3rd, my switch to 4th.... about 2-3 miles down the road, the freeway heads uphill at a slight/moderate incline. Nothing crazy, but it is significantly uphill -- I don't know the grade but it's the kind of grade that you never noticed before you cared about gas mileage/efficiency and now you loath.  It heads uphill for about a mile and a half before heading back down over a half mile and then the off-ramp. The remainder of the drive is 35mph side streets and lights.

I do wonder what my temps would have been if I had stayed in 3rd gear (my 3rd gear will take me to roughly 65mph at 5k rpm) with the higher voltage/lower amps required.... however my pressureplate/clutch disc is a bit out of balance and I try to keep the RPM under 4k in order to keep vibration to a minimum until I can get it fixed. Any thoughts on this from the experts?

My takeaway is this: If you plan on doing a significant amount of highway driving in 85F or hotter ambient temps with the Soliton Jr - you should look into liquid cooling. I, personally, however, do not plan to be in that situation often and might look for an intermediary solution before jumping all the way to a full liquid setup. I'm thinking some sort of cowl to force air cooling at high speeds.

I should note that my controller is directly above my motor (which when I got home was too hot to touch) AND it is out of any sort of airflow. I suspect this contributes greatly to the temps I am recieving and a different setup would likely result in lower temps under the same conditions. The peak controller temp was 88C.










I hope this helps people....


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