# Cruise Control?



## sailfish11 (Sep 15, 2007)

Has anyone set up their EV with cruise control? I realize most EVs are local, limited range cars -- but not all are. Mine will have a range approaching 70 mi on the highway, so I can imagine times when it would come in handy.


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## DONEAL (Sep 10, 2008)

salifish11,
I'm interested in the same idea of using cruise control on my s-10 conversion. I use cruise on my gas burner all the time. I dont think it would be about range as much as just driveing more efficiently or using amp more wisely. Well I guess that would extend your range some what.
I have researched some on cruise control and havent found anything. If you find anything on it, please post your findings.
thanks


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## favguy (May 2, 2008)

I was only contemplating this the other day! I don't see any reason why you couldn't utilise either an aftermarket or oem system for use with an EV, you'd have to find a way to connect and calibrate the throttle control linkage from the original system to the throttle pot of the EV, and on a clutchless system, move the safety dis-engage from what would have been the clutch pedal, to activate via a suitable microswitch(es) mounted to the gear selector linkage to drop out on a shift to neutral to avoid possible damage to the motor, but shouldn't be too difficult to implement


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## Zemmo (Sep 13, 2007)

From what I have read, Cruise Control is only efficient when driving on flat ground (minimal throttle changes). As soon as any hills come into play, the cruise control will start pumping amps into motor to keep your speed. It is also still pumping amps when going down the hill. Where you would see how the terrain is changing cruise control doesn't, it is just trying to keep the car at one speed. You also wouldn't be able to do the pulse and glide method that a lot of people use to extend their range.


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## favguy (May 2, 2008)

This might be a contender for the job if you did want to retro-fit it:

http://cgi.ebay.com/Audiovox-CCS-10...286.c0.m14&_trkparms=66:2|65:15|39:1|240:1318

But as the above poster says, the usefulness of cruise may be limited to flat(ish) highway use, I must admit though, I do like the thought of having cruise fitted when I finish my EV.

Paul


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## TX_Dj (Jul 25, 2008)

Traditional cruise controls did little more than try to maintain a throttle input necessary to keep the engine RPMs (or MPH) at a constant amount.

If you started going up the hill, the old style cruises would have to wait until they noticed a drop in RPM or MPH and start adding more throttle until they compensated for the drop.

These kinds of cruise controls are what you find in almost all but the most modern cars.

The most modern types of cruise controls are simply a program in the ECU that will adjust fuel or throttle according to the load placed on the engine and react much more quickly and accurately to the changing needs of the engine to maintain a set speed.

The modern types cannot be adapted for EV use, because we don't have an ECU that's monitoring everything from firing (or misfiring) to rpm to load % to throttle plate position to crank position to fuel mapping to ... you get the point. In my Taco, it will even go so far as to make the engine a more efficient compression brake by changing the valve timing. With the exception of the more severe hills, my Taco will hold the same speed going up a hill as it does going down the hill, and it will do the severe hills too if I'm in a lower gear when I hit the hill.

The older types can likely be adapted for EV use so long as they monitor MPH from the speedo cable and you've retained the stock speedo setup, or so long as they monitor RPM and you have a speed sensor on your motor.

Like Zemmo pointed out, though... as you start to reach a hill, the ICE cruiser will try to add more and more throttle, ramping up the amps as you come up the hill so you maintain speed, burning off major energy in doing so. It may also try to keep "going" downhill because it doesn't realize the car is heavier than stock and has no compression braking, thus it will try to maintain some amount of throttle while going downhill.

In an EV, you will likely want the car to slow a bit going up the hill so as to reduce the amount of energy you're burning on the climb, and coast down the hill so as to average out what you burned going up the hill.

The most efficient way to drive an EV is with a feather-foot and an eagle eye on the ammeter, and damn the other drivers if they get mad if you slow down going up a hill- sure, you can pull up it at full speed just like they can, but why limit your range to do so?


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## david85 (Nov 12, 2007)

Older cruise control systems like in my truck are adjustable so if you want you could have the car go to max power as soon as a drop in speed is detected. What I did however, was go the other way. I adjusted the cruise control to only have barely enough power to hold speed up a minor grade. Any more power thats needed is still up to me to add with my foot.

I think its a great idea to have cruise control in an EV, although my donor didn't come with it and I probably won't add it this time around.


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## Xringer (Oct 12, 2008)

No matter how steep the hill, the CC on my (plain ICE) Honda CRV 
keeps adding more throttle so it can stay at the setpoint.. 

So, I can sit there and watch the SG2 MPG drop from 30 down to 15 
in only a few hundred yards.. (I can almost see the gas gauge dropping)! 

My idea of a *good* CC is one that acts more like my foot. 
IMHO, it's all those quick throttle up-n-downs that are wasting gas.

I'll bet it's not only possible to make a better CC, but it would be easy for a skilled designer..


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## piotrsko (Dec 9, 2007)

my thoughts: some sort of variable resistance or whatever in parallel with the throttle pedal also connected with a latching relay to the brake pedal light switch.

use a push button to self latch the relay which places the variable in circuit instead of the throttle, adjust the variable to correct speed and viola? step on brake and circuit disengages returning you to the regular throttle.

this will actually be a constant speed throttle, but we used this setup on school buses as cruise because it was there and cruise wasn't.

down side: you loose speed on up hill and go loco on downhills.

I'd draw you a schematic, but it would take at least a day


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## sailfish11 (Sep 15, 2007)

I understand and agree with the comments above about cc not being efficient on hills, but the driver would always be in control to turn it on or off as he/she chose, right?

I imagine the 'brains' of an EV cc would be programmable (via laptop connector) so the user could set parameters to fit their needs (e.g. keep speed within +/- 1mph, if you live near flat roads, +/- 5mph if you live near hills).

Perhaps this could be integrated in the controller, the trick would be how to get speed input to it....


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## Mjolinor (Sep 15, 2008)

If the motor is brushless you have the "speed" from the hall effect feedback circuit, it woudl be relatively trivial to make a cruise control from those signals.


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## Xringer (Oct 12, 2008)

sailfish11 said:


> I understand and agree with the comments above about cc not being efficient on hills, but the driver would always be in control to turn it on or off as he/she chose, right?
> 
> I imagine the 'brains' of an EV cc would be programmable (via laptop connector) so the user could set parameters to fit their needs (e.g. keep speed within +/- 1mph, if you live near flat roads, +/- 5mph if you live near hills).
> 
> Perhaps this could be integrated in the controller, the trick would be how to get speed input to it....



I wish that my CC had a time delay & speed control function on it, 
that would delay the application of power until the speed had dropped by 5% (adjustable).
And then add power slowly over 10 or 15 seconds (again, adjustable).
_Instead of adding power _*instantly,* for any short burst of headwind etc.

The exception would be when the speed dropped greater than 5%
and then kept dropping at a high rate, then ramping up the
power faster would be necessary.

~~~~~~~

After I took a lot of ICE load & weight out of my CRV, my CC started
working in fast surges when going at certain speeds or on certain grades.
I had to tighten up the throttle cable a little to slow it down.

I like the extra spunk the car has *without *the rear wheel drive junk..


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## sailfish11 (Sep 15, 2007)

Mjolinor said:


> If the motor is brushless you have the "speed" from the hall effect feedback circuit, it woudl be relatively trivial to make a cruise control from those signals.


Interesting...I wonder why no enterprising controller manufacturer hasn't incorporated this into their design? If you offered it as an option, I'd bet enough people would buy it to make it worthwhile.


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## judebert (Apr 16, 2008)

I think the question is what you really want out of your cruise control.

I want a cruise control that maintains a particular battery current. It would be nice if it would also respect a minimum battery voltage.

I think that would make the most efficient possible driving.


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## david85 (Nov 12, 2007)

You could just rig a hand throttle or throttle lock for consistent current draw.


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## 1clue (Jul 21, 2008)

I always thought it would be neat to make cruise controls smarter.

For example, you see a lot of GPS devices in cars now. Most of them can hook up to a computer. If you have a computer in there monitoring stuff, even if for a custom dash board, then I would think you could make a really spiffy cruise control.

Mode 1: Use GPS altitude data to anticipate hills. Might not be very effective, but it could help somewhat.

Mode 2: Since most EV's are used as commuter vehicles, your computer could track throttle settings, speed and location through the course of your commute and refine its settings for tomorrow.

Another idea: Use this data not to maintain an exact speed, but rather to make a most efficient commute which maintains a _reasonable_ speed, meaning +- 5mph of posted limit for example.


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