# Soliton Idle on Demand



## Qer (May 7, 2008)

mharvey said:


> All works well but I sure wish I could *not* idle the motor *unless* the A/C is switched on. It seems even if I don't use the start input, once I step on the throttle once the controller will begin idling. I can't see anyway to enable or disble idle without going into the interface and changing it.


Nope. That's by design.

Picture this: You're driving your EV on the spring and since we humans by design tend to be lazy you've got a bad habit during the winter to not bother with the clutch since you don't have to when the motor cuts off completely anyway since idle is disabled.

Then suddenly, when you're waiting in line for a red light and you're busy changing radio station the AC suddenly decides that the feeble spring sun has actually managed to heat up the passenger compartment so much that it's time for it to do it's duty for the first time that year. So when you're busy trying to find a radio station that isn't playing one of those awful songs that all of them seems hell bent on torturing you with the AC switches on, the Soliton turns on idle, the car lurches forward and before you've managed to react you've rammed the car in front of you and the now somewhat pissed off guy in that car is getting out of his demolished car to ask you what the hell you're doing!

So, well, yeah, features like this has been considered but since we value our customers lives higher than kWh they tend to be scrapped if they have even the slightest touch of impending doom. Exception: Shiva. 

Besides, how many Watts are we talking about? When the AC is switched off it can't really cause much of a load, can it?


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## mharvey (Oct 30, 2009)

Qer said:


> Nope. That's by design.
> 
> Picture this: You're driving your EV on the spring and since we humans by design tend to be lazy you've got a bad habit during the winter to not bother with the clutch since you don't have to when the motor cuts off completely anyway since idle is disabled.
> 
> ...


The total energy loss would depend on driving style and conditions as you know. Say it's a 3a draw at in this case at 130v (to idle under no load but have enough power to survive a compressor engaging), but the driver sits at lights for half his daily commute. I could do the math but I would need to know the total idle energy consumption vs. the driving energy consumption. But really, basic logic would tell me that he is wasting a good percentage of his capacity that could be avoided most of the year at least. 

Since it's really all about efficiency, and we shave lbs, put on LRR tires, remove non-essential bits from the vehicle, install AC heaters to preheat the cabin, etc. to squeeze and extra 5 miles of range from a charge. I'd say idling the motor 70% of the year for no reason is a waste of energy. I was sighting the "turn on with the A/C" as an example since the vehicle I am referring to has no thermosatatic controls, and is manually enabled, and only turns on when the blower is on, so I don't really see the danger in my case. Besides, idle power should hardly get the vehicle up to "life threatening speeds" anyway. Driver could inadvertantly step on the accelerator too, which is more likely.

What I was really asking for was a way to enable/disable the idle without having to go into the web interface since I can't lock out some parameters and let a novice change others. That to me would potentially be way more dangerous to the customer if they inadvertantly changed the wrong bit. 

The ability to put a toggle switch in the engine bay that I can have the customer flip on in June and off in September would be fine, and there would be no chance of someone turning it on by mistake while looking for some gum in the glove box. Without it will be forced to show the customer how to turn idle on and off and I really don't believe that is "safer".

And let's not even argue against A/C. I dont have it in my EVs. But if we really want to have viable alternatives to ICE, we really can't avoid it.


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## Tesseract (Sep 27, 2008)

mharvey said:


> ...I was sighting the "turn on with the A/C" as an example since the vehicle I am referring to has no thermosatatic controls, and is manually enabled, and only turns on when the blower is on, so I don't really see the danger in my case. Besides, idle power should hardly get the vehicle up to "life threatening speeds" anyway. Driver could inadvertantly step on the accelerator too, which is more likely.


Sure, using a manual switch to turn idle on and off is not too dangerous, but what's to stop someone using the wire going to the A/C clutch to toggle idle instead? Now imagine such a vehicle coasting along at a low speed when the A/C compressor kicks on and the controller obligingly ramps up motor current to as high as the 400A maximum allowed to achieve the target idle RPM? Make the venue a crowded parking lot (with lots of baby strollers for added drama) and it's not too much of a stretch to imagine how this could turn out badly for all involved.

These are the kind of situations that Qer and I must consider whenever someone makes a feature request.

We'll give it some more thought - indeed, it's not like we hadn't thought of this already ourselves - but if we decide to not implement it then please respect our decision. After all, it's not *you* that will get sued into oblivion should something bad happen, eh?


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## Woodsmith (Jun 5, 2008)

I wouldn't like it, for all the reasons Qer and Tess have mentioned.

I wouldn't be happy with a controller starting or ramping up a motor outside the driver's immediate control.


I have been caught out a few time when I first bought a new diesel car. The anti stall would increase the power to the engine if it was below idle speed and there was no driver interaction.

I am used to creeping the car in heavy traffic on very low throttle openings. However, if the engine speed was below idle when I moved my foot from the throttle to the brake, the anti stall would accelerate the engine to bring the stall speed back up resulting in the car surging forward when I most wanted it to stop.

A few times I was close to rear ending the car ahead.

Now I know about it I ride the brake, when creeping in traffic, against the anti stall. The engine still surges when I declutch to a stop but at least it isn't driving the car then.

The anti stall is able to produce enough power to pull away up hill, when I let up the clutch, without any throttle. 
I can imagine that if, as Tess says, the Sol 1 was to dump 400A to maintain idle if it felt it was required it could produce all sorts of 'out of control' events.


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## PhantomPholly (Aug 20, 2008)

If you are using an automatic transmission, the feature could be implemented in exactly the same way it is on ICE vehicles. Simply have a solenoid activated by the same circuit that activates the AC clutch which bumps the throttle minimum position up from "zero" to "minimum idle."

I agree with the Sol makers that that would not be a great idea in a car with a clutch, even though that's also what they do with ICE vehicles, for the reason that the driver would have to be aware that "idle" has bumped not from "low idle" to "AC idle" but rather from "zero" to "AC idle." Those in the habit of never using their clutch might thus bump the vehicle in front if the AC were to activate at an inopportune moment.

An alternative is a small DC motor directly coupled to the compressor and activated by the old clutch circuit, or a DC motor that runs all the time perhaps including the vacuum pump for the brakes and/or power steering pump.

Smart guys - if a DC motor runs at a particular RPM based on volts, will it automatically draw less or more amps based on load or will it draw continuous amps and shed RPM?


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## dougingraham (Jul 26, 2011)

PhantomPholly said:


> ISmart guys - if a DC motor runs at a particular RPM based on volts, will it automatically draw less or more amps based on load or will it draw continuous amps and shed RPM?


Volts commands RPM. The motor draws more or less current to hold that desired RPM. Ideal motors would hold RPM very well. In one respect we need to be glad we don't have ideal motors. If we did they would break stuff all the time. The losses protect us from this. As the load increases they will try to hold RPM but as the current goes up the apparent voltage the motor sees will drop from resistive losses and battery sag so the RPM will drop some too. But the current will continue to rise up to a point as the load increases.


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## mharvey (Oct 30, 2009)

Tesseract said:


> Sure, using a manual switch to turn idle on and off is not too dangerous, but what's to stop someone using the wire going to the A/C clutch to toggle idle instead? Now imagine such a vehicle coasting along at a low speed when the A/C compressor kicks on and the controller obligingly ramps up motor current to as high as the 400A maximum allowed to achieve the target idle RPM? Make the venue a crowded parking lot (with lots of baby strollers for added drama) and it's not too much of a stretch to imagine how this could turn out badly for all involved.
> 
> These are the kind of situations that Qer and I must consider whenever someone makes a feature request.
> 
> We'll give it some more thought - indeed, it's not like we hadn't thought of this already ourselves - but if we decide to not implement it then please respect our decision. After all, it's not *you* that will get sued into oblivion should something bad happen, eh?


There was no disrespect intended. I was merely debating the risks and benefits. I respect your position and your decision. Ill just write a custom post url with the idle presets to turn the idle on and off and show the user how to clicky the shortcuts. That's about the safest thing I can do. After all the query strings are there for all to see. Thanks for your consideration of my request and keep up the good fight.


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## PhantomPholly (Aug 20, 2008)

dougingraham said:


> Volts commands RPM. The motor draws more or less current to hold that desired RPM. Ideal motors would hold RPM very well. In one respect we need to be glad we don't have ideal motors. If we did they would break stuff all the time. The losses protect us from this. As the load increases they will try to hold RPM but as the current goes up the apparent voltage the motor sees will drop from resistive losses and battery sag so the RPM will drop some too. But the current will continue to rise up to a point as the load increases.


But that sounds wonderful - a motor such as that will use only the current necessary to do the work asked of it!

It would seem, then, that the ideal solution to "complex vehicles" (those with vacuum and power steering and air conditioning) would be to use a DC motor for "accessories." That motor could be run independent from operating the vehicle, so could in fact keep your car cool while you run into the store on a hot day.

Enough daydreams - why is that not what everyone does?


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## Woodsmith (Jun 5, 2008)

PhantomPholly said:


> But that sounds wonderful - a motor such as that will use only the current necessary to do the work asked of it!
> 
> It would seem, then, that the ideal solution to "complex vehicles" (those with vacuum and power steering and air conditioning) would be to use a DC motor for "accessories." That motor could be run independent from operating the vehicle, so could in fact keep your car cool while you run into the store on a hot day.
> 
> Enough daydreams - why is that not what everyone does?


Wouldn't a small shunt motor do that?

Shunt motors will hold rpm and demand current to achieve that.
A small shunt motor, with a contactor for on/off, to drive the AC, PS and vacuum pumps at their ideal speeds and the traction motor to just deal with traction.


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## mharvey (Oct 30, 2009)

Woodsmith said:


> Wouldn't a small shunt motor do that?
> 
> Shunt motors will hold rpm and demand current to achieve that.
> A small shunt motor, with a contactor for on/off, to drive the AC, PS and vacuum pumps at their ideal speeds and the traction motor to just deal with traction.


 
I've also been tinkering with the idea of using a Prius Compressor. Just need a DC/DC to step up the voltage. I've heard of other folks doing this. Anyone tried it?


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