Bench Envy – the GEVCU begins to show its stuff.

I’ve rather failed to keep up the blog in the past few weeks. I have been kind of in a hole with the Generalized Electric Vehicle Control Unit software with the latest final version ever just around the corner. It’s refreshing and very enjoyable to be back in code though a little rusty. And so on a number of days I’ve simply failed to make it into the shop and neglected various other duties while focusing on getting the web interface to work etc. It’s been a little obsessive.

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But its been an exciting week and gratifying. Some of our activities take quite a while to mature and several of those came together this week.

First the GEVCU progress. We’ve added some mundane but needed features – at least for the VW Thing implementation. We have completed the precharge function or completed A precharge function. I’ve actually come across an alternate strategy for this that bears a mention and so was mentioned in this week’s show.

Consider the circuit diagram below. We normally have a main contactor and a separate precharge relay. The precharge relay, often just an automotive 12v, connects the battery pack to the inverter through a precharge resistor – typically a power resistor of 50watts or more and anywhere from 50 to 750 ohms. The resistor serves to restrict the inrush of current to the input caps of the inverter controller. This is kind of necessary on ANY component that has internal input capacitors – DC to DC converters come to mind but also air condioner motor drives and more.

Once the caps are charge at a low current level through the resistor, the main contactor is closed effectively connecting the battery directly to the inverter input caps and largely bypassing the precharge resistor.

The problem is the little precharge relay. It’s just not meant for higher voltage. We recently added a Tyco precharge relay to the product line. It IS rated for high voltage, but almost doesn’t make sense at the neceassary pricing of $99. You can very nearly buy a true high voltage high current contactor for that amount of ducats.

Ryan Bohm actually came up with an alternate topology for this for his Netgain Controls WarpDrive Industrial. The system uses TWO contactors, one on the positive input and the other on the negative input of the inverter. Again a precharge resistor is provided but it is simply connected across the two positive leg contactor terminals.

prechargecircuit

The magic is of course the contactor on the negative side. No current flows through the precharge resistor and no power to the inverter until you close the bottom contactor. At that point, the circuit is closed and the current through the resistor precharges the input caps on the inverter. Once they are up to battery potential, you close the top contactor, bypassing the resistor.

This is actually a simpler configuration, and avoids the wear and inevitable failure of the little 12v relay from high voltage. HIgh voltage has in the past been 200v. We are rapidly moving to 330vdc or even 400vdc for modern drive trains.

Actually with this circuit, you can apply IGNITION switched 12v to the lower contactor and, for example, the power input to the GEVCU and to the Inverter all simultaneously. THis starts the precharge cycle. Once sufficient time has elapsed to be charged, you simply engage the upper contactor.

We added a couple of other “features” to the GEVCU. A cooling fan output for example. We have dual heat exchangers on the VW THing and they are kind of monster Deralis, with an appropriate throaty howl when they run. We don’t need them in town. We can’t drive without them on the freeway. The trick is of course the inverter and motor cooling. The DMOC645 has a pretty severe current limit that kicks in at exactly 80 centigrade. So we want to keep it below that. With our pump and heat exchangers, this is easily accomplished in town WITHOUT the heat exchanger fans. But on the freeway, the system quickly heats up to beyond 85 degrees. Fortunately, the addition of the fans to the mix is more than enough to bring the temp down. So the kicker is when to run the fans. We don’t want them howling at us while we maneuver in the driveway, and we have to have them under load.

Fortunately, the DMOC645 reports motor rotor temperature, motor stator temperature, and inverter temperature all to the GEVCU via CAN. So we can simply monitor actual temperature and when it gets to 70 or 75 degrees, use one of our GEVCU outputs to turn on the heat exchanger fans. Then, if it cools to some lower value, say 65 degrees, it will turn them off. By having TWO specified temperatures, we can avoid the hysterisis that would inevitably occur if we simply set it to 70 and let it go. It would then “hunt” rapidly around the 70C mark.

Finally, AC motors give us the gift of regenerative braking. This is actually a mixed blessing and does not achieve the energy recovery most people accrue to it. But we’ve gotten addicted to the feel of braking with our throttle. The problem is, with aggressive regen, we slow the car quite capably and even dramatically without touching the brakes. That means we never turn on the brake lights.

Brake lights are actually kind of important. When you are in a moving vehicle FOLLOWING a moving vehicle it can be eerily difficult to detect changes in speed n the car up ahead. So we’ve grown accustomed to the warning of two great big red lights that come on when the vehicle ahead slows. Without them on your vehicle, you risk having others climb into your trunk every time you slow down dramatically.

So we added a function to select one of the eight outputs for brake light. You can use this to switch a relay which bypasses the usual brake light switch. This output will switch on anytime the actual motor torque exceeds 10 Newton Meters of negative regenerative torque. So you can slow down a little without triping the brake lights. But anything significant will result in a brake light illumination.

dashboard

configscreen2

statusscreen

We also did some work on the wireless website configuration screens to make them more informative and to fix a lot of things that were just broken. One of the things we added was a kWh meter. The DMOC645 also reports battery voltage and current and we can use this to calculate energy use in kiloWatt hours or kWh.

Actually we calculate it in kiloWatt milliseconds and store them in EEPROM. We DISPLAY them in kiloWatt hours by dividing this number by 3,600,000. And so each time you get in the car and start it up, it retrieves the stored kWms and then starts adding to it each timer increment based on the power coming out of the pack.

The problem with these kind of meters is resetting them. We actually do NOT have a way to monitor charging as yet so we cannot measure the power coming back in from a charger. I have cars where you have to manually “reset” the meter and the problem is that I forget to reset it. This results in a very innacurate meter.

For GEVCU, we allow you to enter a fully charged pack voltage. For LiFePo4 systems, this is often 3.34v per cell. That’s the charge on the cell after it settles a few hours after charging. So we ould normally set our fully charged voltage to something beneath that by a small amount. Like 3.30v per cell. In this way, the kWh meter is reset on any tick where the pack voltage exceeds the entered voltage.

And so whether you have just finished charging and are at 3.55 per cell, or if it is some hours later and 3.34v per cell, the meter continously resets.

What we know, is that if you get in the car and back down the driveway, by the time you reach the road you will bleed off the surface charge on your cells and the voltage will fall below 3.31. At that point, the kWh meter begins its count.

It is also interlocked by negative torque, so if you spike the voltage using regenerative braking, it will NOT reset.

We actually have about 30 GEVCUS already delivered with earlier software without these features. Unfortunately, as we are based on Arduino, there is no easy way to magically upgrade the software in them. You have to install Arduino and recompile the source code to update it. Fortunately, that’s not as hard as it sounds but I have done an instructional video showing how it’s done.

The other interesting thing this week was receipt of our first Scott Drive. This is a 150kw maximum AC inverter from New Zealand that has been characterized for the Siemens 1PV5133 motor. And unlike some of the testing, this has actually been run on a test bench WITH a load generator.

While this drive has been bench tested with the Siemens, it has never yet been used with a Siemens in anger in a vehicle. We are currently discussing becoming a dealer for the Scott Drive and assuming that all happens, we’ll be commencing one soon. The Scott Drive DOES feature a CANbus connection but it is unclear to me at this point whether we can actually control the drive with it or if it is just used to interact with other devices – such as a BMS.

We have actually had a Rinehart Motion Systems inverter for a couple of months. GEVCU development has rather precluded our tearing down our one test bench to do any of that.

And finally, we now have 10 UQM Powerphase 100 systems from teh CODA bankruptcy. We have to develop an object module for the GEVCU to drive it.

And so this past week I made a command level decision to go into test benches in kind of a big way. We are building one for the UQM and another to test compatible inverters for the Siemens. Indeed, we could well wind up with a test bench for each inverter we carry. Questions are going to come up and often the only way to answer them is to go to the bench and try it.

The UQM bench kind of fell into our lap. It turns out it uses the same eGearDrive shaft and coupler as the Siemens so it was trivial to couple the UQM motor to one of our Siemens motors. SImilarly Hauber’s dual Siemens allows us to run a Siemens motor for test, with a Siemens motor generator for load.

I did imply that we would do this by adding a 3-phase rectifier to the Siemens motors to produce DC. And that was the intent. But we also needed some capacitors to excite the stator windings, which is no big deal. But Paulo ALmeida has been persuasive that we really need a couple of our dwindling supply of DMOC645s as it would allow us to both control the load, AND to display it on a GEVCU wireless web site display. He’s right again of course.

This will also allow me to experiment a bit with something I’ve been wanting to try. Some version of the AC propulsion strategy of connecting 240vac to the motor windings and using the inverter to control charging a battey pack with regenerative braking from the grid. I’ve always wanted to play with that and these test benches ought to sratch the itch.

Recall we received two oddball A123 battery packs from the Better Place battery raid. We’ll use these on these two benches to get a smooth 360v source for them.

So overall, the test benches are going to be a bit costly to implement – kind of like an entire car build on a bench. But we think it is a future direction we need to go.

Meanwhile, Damien Maguire has an inverter working as well. So we are quickly moving from having a bunch of motors and no inverters, to having inverters to pick from.

I must say the size of the Rinehart Motion Systems inverter is just tiny compared to the others. This little inverter with a Siemens motor and some of the new CAM72Ah cells from CALB would make a very small light package for a little yellow sports car I’m thinking.

Speaking of packages, we are running a one week sale on the High Performance Electric Vehicle Systems AC35x2 system. This lists for $9395 and we normally offer it at $8900 just to come in under $9000. For this week, we are going to offer it at $7400 with FREE SHIPPING to lower 48 US commercial addresses or nearest UPS terminal.

ac35-kit

Till Friday noon.

Stay with us.

Jack Rickard

66 thoughts on “Bench Envy – the GEVCU begins to show its stuff.”

      1. It’s just another module Jack! =D

        I have to say, it is looking very nice and easy to use. I think my dad could set it up and he doesn’t even have a computer…

        1. It has kind of moved way back burner, but no, it would communicate via CAN as well.

          We might do a module to control TCCH chargers for the GEVCU. I’m graduallyt learning that other chargers, such as Shinry, use almost identical CAN addressing and messages. But we can’t do much with the kWh meter based on the charger because we don’t know what charger they are using in any particular applciation.

          I’m kind of looking at a “generalized” BMS. I have, for example, a hall effect current sensor that itself reports via CAN. If I can find a suitable voltage/CAN sensor, there are some interesting things we can do.

          Right now, I only have the GEVCU ON when the ignition is on. There is no religion there. But if we had it on all the time, I would want some way of resetting it. Getting a fresh start each time we start the car is kind of attractive to me.

          Jack

  1. I am also working on a version of the AC Propulsion combined inverter/converter for battery charging. I think that will add significant value to the AC setups if they can also be used for battery charging. I look forward to that project. Thanks for sharing your work.

    Jeff

  2. Dennis Carter

    Having the brakelights come on above a certain torque level of regen seems like one of those simple ideas that can make a real difference in safety.
    Reminds me of an article about a 70’s showcar that had an extra set of yellow taillights that came on when you let off the throttle all the way.

    1. Not only regen but *also* with the motor slowing down at the correct rate. Or the brake lights will be on while maintaining a downhill speed.
      Nothing stays simple when including other issues ๐Ÿ™

    1. Cruise control on an EV could be done, but wouldn’t necessarily be easy. With an automatic transmission, you would have to have access to road speed data, motor RPM would not be enough information. With a manual transmission you could rely on RPM, as long as you disabled cruise every time you shifted gears.

      1. On some after market cruise kits the engine signal and the VSS signal can be swapped. On my ICE version built for CAN throttle control when I track RPM it holds that engine speed no matter the gear. When hooked properly to VSS the controller tracks road speed and only cares about over speed. It shuts off the cruize when RPM is way too high. I don’t have a clutch safety switch, that’s how I know.

    2. So far no suggestions as to cruise control. The problem is of course speed. I thought about a GPS early on. It just didn’t make the cut as it added little beyond easy kWh per mile.

      On systems with OBDII, I think we’ll eventually be able to steal speed. At that point, it is very feasible.

      Jack Rickard

      1. Jarkko Santala

        Here’s something, Cruise Control tries to keep set RPM, but disables if:

        – There is increase in throttle input
        – There is increase in brake pressure
        – There is a sudden change in torque required to maintain RPM (this should detect clutch engage or gear change in automatic)

        That would of course disable CC if a steep hill comes and gearbox does a kickdown, but if you have a big enough motor, does it really do that? Is there any other reason the gearbox would change than change in RPM?

        1. Hmmm, interesting idea. I don’t know that I’d advocate for disabling cruise if there is an increase in throttle input. Normally CC lets you accelerate a bit and then just settles back to your set point. The idea to monitor torque is a good one.

          It might only be necessary to disable cruise if the torque changes a lot and quickly. Going up a hill will increase the torque demand but somewhat gradually. Shifting is much more rapid. Electronic control has the advantage that it is working much faster than a person could react. For instance, the DMOC sends status frames at something like 30ms intervals. So it would be pretty easy to keep a very close eye on torque to see if it went from 120Nm to 15Nm in a matter of 60ms which would tend to suggest that shifting is going on.

          I do think that CC should be implemented at some point but I think it probably won’t happen until things are a bit more stable in code. In the meantime it is good to have these discussions because there are a lot of “gotchas” to doing this properly.

          1. I agree with Collin. There is more going on with CC than appears at first glance. ANother one of those simple little things that turns out not to be not so simple. And doubly so for GEVCU.

            You see we don’t know what kind of car you are going to put it in. It would be fairly simple to do a PID around rpm. This would certainly work on a single speed gearbox but would likely also work on a manual transmission. If you are “in cruise” you are unlikely to shift the transmission. In fact it almost implies freeway and top gear.

            But the same concept on an automatic could be disastrous. Start up a small incline, the transmission downshifts, the rpm jumps, and we immediately bring the torque down drastically to reduce the rpm…..well you get the idea. On upshifts, it could be even worse, sudden uncontrolled acceleration.

            IF we maintain torque, we are actually commanding increased acceleration. When we say we have torque control, the reason this works in a car is YOU are the governor. You increase torque until you reach the desired speed, and then you automatically and without thinking about it reduce pedal to maintain speed. That reduces torque. Your foot will work out how much pedal to maintain the speed for us. All we have to do is produce consistent torque from pedal input.

            If we try to maintain a steady torque, we are either continously accelerating or continuously decelerating.

            The only reliable way to get speed is from a wheel speed sensor. We COULD conceivably snag this from sniffing the OBDII and this would work on SOME cars. Speed is actually one of the mandated PIDS and so shouldn’t vary from vehicle to vehicle as a rule and kind of by rule. But we don’t know if you even have OBDII and as soon as I say that, someone will point out an exception on some vehicle anyway.

            There are CAN enabled GPS modules. We could derive speed from that, and disable CC on lost signal. But that’s several hundred dollars usually for not very much added utility.

            Doing it based on a speed input on one of the digital inputs would make the most sense. Then you have to provide some sort of wheel based speed pulse. But it gets into a lot of code for configuration options to do the cruise control which itself is a trivial amount of code. Which input port do you want to use. How many pulses per revolution. Do you want cc at all. Then you have to have ANOTHER input to enable/disable cruise. And most modern cruises have a plus and minus bump button as well. So we would have speed pulse, cruise on/off, cruise plus, and cruise minus, and that would use all four available digital inputs just for cruise.

            Im’ not terribly enthusiastic. I had cc on the Escalade and disabled it somewhere along the way. In practice, I’m only ever on the freeway for a few minutes and never used it. We originally used the throttle body as the throttle input and the EC took care of cruise. But it took care of too many other things so now we just use the throttle pedal signal as throttle input and I have a lot less complication in my life. I gave up cruise, and just don’t miss it enough to go back.

            So conceptually GEVCU could do cruise. I’m just not excited enough about the feature to code it myself.

            I kind of plan some future use of the digital inputs anyway and will probably add configuration items for:

            ENABLE – digital input none, 0,1,2, or 3.
            DISABLE – digital input none, 0, 1, 2, or 3
            FORWARD/REVERSE – digital input none, 0, 1, 2, or 3
            REGEN ON/OFF digital input none, 0, 1, 2, or 3

            Jack

          2. Collin,
            You’re right, I don’t know why I listed increased throttle. If I had an idea why it would be a good idea, I don’t remember it anymore. It should though not increase torque until you press the pedal enough to actually accelerate. To make this work, I guess would be easiest to make CC work so that it would in fact fake throttle input to a level required to keep set RPM, this way you’d know when to start reacting to actual throttle input – when it exceeds fake throttle input from CC. Obviously throttle input below that value should be ignored to prevent regen and whatnot. So, yeah, lot of things to think about and gotchas too.

          3. Jack – interesting that you disabled CC on the Escalade. I was hoping to use CC in the Civic courtesy of the original ECU if I could figure out a way to get throttle position off the CAN bus and stuff it into the Curtis. I have used one of the the throttle pots directly quite successfully but it would be nice to have CC plus the fail-safe redundancy built into the dual pots

  3. Has anyone noticed any “softening” of CALB SE cells over time?

    My batteries have been in use for about 2.5 years now and I’ve noticed a couple of things. The first is that neutral braking doesn’t seem to be as strong as it once was. In second gear at 35 MPH I used to see about 100 A of regen with my setup. Now I only seem to be putting in about 80 to 85 A. The second thing is that charging seems to take longer. This I don’t have any hard numbers for but I’m going to say charging takes round 25% longer than it did a couple years ago. I had wondered for some time if it was something with the charger but my clamp current meter still shows the same amount of current going into the batteries as there has always been.

    It just seems very curious and was wondering if anyone else has noticed similar behavior. What bums me out is extrapolating this out over time. What if in a few more years it takes 50% longer to charge? If these losses are just going into heat then perhaps at some point temperature might start to become an issue?

    -Jon

    1. Jarkko Santala

      Have you checked all your cables and connections to make sure your not converting that extra power into heat at some point? Also is there a possiblity something else is sucking power while regen and charge – does it show zero amps when it should?

      1. Jarkko Santala

        Also the obvious: check that your total voltage after charge and rest is the same as it always has been, cell voltages are consistent after charge+rest and do not not wildly vary during charge (like some shooting over 4 volts right away). A bad cell could be the issue if these tests do not pass.

        1. Yes I agree with Jarko – I’d look for other problems first. I have not observed the increasing charge amp-hours you describe in either the CA series tests or in the Headway tests I have conducted, and I’d be surprised if the SE cells were radically different (although anything is possible!).

          In both Headway and CA tests the amp hours pumped in on a maximum effort charge gradually decayed broadly in line with the amp hours delivered on a maximum effort discharge. For example during cycle 100 for the CA cells, charge consumed 35.9 Ah (starting from around 25% SoC) whereas cycle 1700 charge consumed 33.2 Ah. Equivalent figures for the Headways (over fewer cycles) were 7.13 Ah and 7.06 Ah

          1. I noticed longer charge times in my pack just prior to finding the shorted cell and a loose connection. My cables were getting hot as well.

  4. DC charging from three phase AC motor could be accomplished using the DC bus link of some industrial motor controllers. For example the Control Techniques Unidrive line SP has as common DC bus which can be set at 200, 400, 575, 690 VDC and is used for regen applications. This allows dynamic braking of one motor to power another or be fed back to the grid. Usually the DC link doesn’t care where the DC goes, many times we feed it to a braking resistor bank. I worked on an small 20kw wind turbine application which used two industial motor controllers, AKA VFD’s. The first was just hooked to the turbines three phase motor, the second connected by DC bus was hooked to the grid. The second VFD was programmed to send all of its energy back to the grid via the DC bus link. Diagram: http://www.joliettech.com/images/unidrive-sp_ac-drive_regen-solutions.gif

        1. I’m not sure why Discovery would block the UK on Youtube… Wierd.

          A buddy of mine had TiVoed the episode, and by now Jack should have a copy, so we may be able to see some “fair use” segments of the show on EVTV.

          Mr. Hardy, contact me at evtv at stansimmons dot com if can’t find another source for the video.

          1. Just looked. It’s been pirated. The problem with the UK who want it this way is bypassing the blocks forced on to the ISP’s.
            Sad days. Those who control the internet think they own the internet. As most things these days.

            However, it’s one of those really annoying contrived docu’s but I really enjoyed the outcome :))

        2. Same here in New Zealand John. I don’t mind paying the $2 to watch the show so why would they care which country the money comes from. The web can sometimes feel very “Americentric” if that is even a word.

          1. http: //piratebay. com. co .. Herein a special “browser” to alleviate finding their blocked web pages.

  5. michel bertrand

    Hi Jack , really liked the video of the battery being dismantled !
    I see you are having a vigorous development with the Gevcu . It gives me warmest happiness
    michel

    1. The dismantling video was kind of long and boring I thought. But it made a crucial point in that the battery is much better constructed than I had any reason to believe. And the can opener and 3 foot machete were just too precious for words…

      Jack

  6. just paid for and watched that show, 1.99 for show and 11cents tax. About two thirds of show about them trying to flip a car, spent 21000 and sold for 18500. I thought we have seen Billy Jr , got it he was seen getting an EV grin driving around in Jehu’s Samba. Jack I do not have bench envy
    it is just envy.
    Steven

  7. Who’s Killing the NY City’s Horse Drawn Carriages?

    This might make a good news item on EVTV from Autoweek:

    “At the New York auto show Florida-based car restoration firm The Creative Workshop introduced an eight-passenger electric horseless carriage designed to replace today’s horse-drawn carriages. The company says its car blends โ€œearly 20th-century style, nostalgia and romance with 21st century eco-technology, comfort and safety,โ€ calling the Horseless eCarriage the first brass-era-type car in more than 100 years.”

    “Reportedly the car meets all NHTSA safety standards. TCW president/owner Jason Wenig designed the lithium ion battery-powered machine with rear-wheel-drive, 84-hp and 184 lb-ft of torque, boasting a 30 mph top speed and a 100-mile range.”

    Read more: http://www.autoweek.com/article/20140418/newyork/140419832#ixzz2zGZkhbM6
    Watch video: http://abcnews.go.com/Business/video/horseless-ecarriage-draws-yays-neighs-23370790

      1. Edison had a point about local power generation but after he conceded the three AC generators he made all fought with one another because one AC cycle attempted to push the other AC generator into an opposite phase. It got worse!
        Edisons idea of clean death by electricity was first attempted with AC. the electricity passed over the victim inside of through him and totally failed to cook the guy after many attempts. Leading to the famous quote “Could of done better with an ax” (axe).

        For all the money they made, scientifically, they were fairly brainless and stumbling.

  8. Hi Jack,

    I just watched your 4/18/14 show. You announced the CALB SE 100AH liquidation sale ($0.95/watt, with bolts, Nordlock washers, and connectors). This is a great deal. The eMinor is using 200AH Sinopoly cells manufactured at about the same time, and using a similar chemistry. They are working great in a car I drive frequently. I haven’t noticed any deterioration, but I have not explicitly tested for it. Your price in 2014 dollars is less than I paid (about $1.10/watt without bolts, washers, and connectors) in 2011 dollars. Barring the Influenza sale, a special situation, this is the best battery sale I have seen since I bought the Sinopoly cells. I am thinking about building a removable parallel pack for range extension…

    John Bishop

    1. I really enjoyed the ride-along in the e-minor at EVCCON. I may be way-off on units. Jack has seen me hit the technological tree on the side of the road. It’s not pretty. Should that read $0.30/watt-hour?

      1. Stanley, I appreciate the gentle correction. I meant to use “AH” instead of “watt.” My math and physics professors weren’t so gentle, and I flunked out of engineering school because of this sort of thing. Fortunately, after only 10 years, I got my undergraduate degree in psychology! And, fortunately, my brother built the eMinor.

        John Bishop

  9. I have not heard anyone mention it yet, but if you have rear wheel drive, you need to be careful about regen. Espesially when on a slippery surface such as snow or ice. If anyone has tried the parking brake at speed, you will know what I am talking about. It will basically put the car in to an uncontrollable spin.

    1. I have to ask, is this something you have done yourself? Have you been in an uncontrollable spin caused by regenerative braking because of slippery surface such as ice or snow?

      The reason is I have driven the Tesla Model S, the Speedster Duh, and now the THING on slippery ice and snow. I have not only not encountered ANY negative effects, but found them particularly catlike on ice and snow. The Escalade absolutely plows through it effortlessly albeit it does not HAVE regen. Even stopping on black ice is remarkably facile for an 8000 lb beast with the ABS disabled.

      So I have to ask, is this:

      1. The result of a thought experiment that “only makes sense” to you.

      2. Something someone has told you.

      3. The result of a firsthand primary experience with you at the wheel.

      If number 3, please fill us in with the details: Road conditions, car description, what lead up to the incident, and outcome.

      We’d really like to know.

      Jack RIckard

      1. Here’s a bit of footage what the typical winter driving looks like around these parts (not my video), imagine temperature of about -20’C (-4’F):

        https://www.youtube.com/watch?v=Fe8j8RUzgXU

        Now, if you’re doing 50 mph (80km/h is our usual winter limit) on a road that’s not just black ice, but thick with ice, and you’d suddenly let go of your throttle and engage regen on rear wheel drive, you could bet you’re ass you’d find yourself removed from the road.

        The Tesla Model S is a modern vehicle with active monitoring on each wheel, which will prevent them from slipping – either way. That, weight and low center of gravity makes it a relative good winter vehicle, for a rear wheel drive. You can’t compare it with GEVCU with no traction control.

        I wouldn’t attempt to prove this except maybe in a purpose built reinforced vehicle, on a close ice circuit and proper safety gear including a helmet.

      2. Jack,
        Recently you revealed several details about changes to you Escalade build that would be valuable information to your viewers that were doing similar builds of “fooling the PCM, ECU, or ECM” by means of a rotating reluctor wheel and the crankshaft positioning sensor.
        Originally you were using the 0 to 5 vdc signal off the GM throttle body and then through a amplified circuit to the Solitons, but now you just use the 0-5vdc of the accelerator pedal. Why did you make that change? Cruise control seems like a feature one would want to keep.
        The serpentine belt that rotates the reluctor wheel on the front of your Jim Husted dual 11″ was slipping causing you all sort of problems with your GM6L80E transmissions. Since you fixed the slipping problem you now can drive 80 m.p.h. on this very sophisticated can- bus computer switching solenoid activated transmission,
        So since the slipping problem has been remedied how is it shifting in normal operation?
        So you disabled the ABS. Why? on this fooled PCM, ECU, and ECM that communicates to the GM BCM, (body control module) that to my knowledge controls the 4 channel EBCM, (electronic brake control module}…stability control.
        I appreciate all that you do to further the cause of individuals building their own electric vehicles. Maybe you could enlighten us all with a follow-up video on more details of your Escalade build.
        Thank you,
        Mark Yormark

  10. Your answer is 1. I did ASSume this because of much firsthand driving experience. of gas rear wheel drive cars. If I put a car into lower gear (of which I am ASSuming is like regen) down a snowy hill at speed, IT will kick the ass end out on ya. I’m sure the Model S is smart enough to not let the rear wheels slow down more than the front. And I will ASSume that the Escalade is running in all-wheel drive, keeping front and rear wheels the same speed. I do not know or have any experience with regen, I was just trying to help in an area that I thought that if overlooked, may hurt somebody someday. Maybe the DMOC already has something built in its firmware to not allow an abrupt slow down in wheel speed while regening. OR I may just be a dumbass. either case I didn’t mean to start trouble.

    1. You didn’t start any trouble. You tried to type yourself smart. Now predictably enough, you have Jarkko chiming in and typing HIMSELF smart.
      And of course going further out on the limb. What kind of moron drives 50 mph on a road “thick with ice” Jarkko?

      This is perfect DIYelectricjunk protocol but doesn’t work very well here. Kind of like O”Reilley’s “NO SPIN” zone we just don’t have room or time to read posed theories of thought experiments. If you have some DIRECT experience with an electric car using regen on ice that contradicts mine (or not) we’d be pleased to have it included for the edification of all of our viewers.

      One of the reasons EVTV is the way it is, is that I’ll think you will find that many of our viewers came to us after very expensive mistakes, caused directly by well meaning advice on forums such as DIYelectric that turned out not to be such very good advice. This largely because the poster was THEORIZING on what MADE PERFECT SENSE to them at the time they wrote it with the very best intentions. The reader, however, took it as advice from an experienced and knowledgeable party and acted on it ducats akimbo.

      I will confess, the natural tendency to do this is so overwhelming I regularly fall into this trap myself. After all, it ONLY MAKES SENSE. I have to continously remind myself – if it makes so much sense, then SHOW them, don’t TELL them. Our viewers actually learn more from my failures than from my successes. And it may well be that we’ll some day in the future film a shot from a ditch ruefully acknowledging that you were right. So far, all of my direct experience with electric drive on ice and snow has been absolutely a total surprise. The surprise is how very WELL it operates on ice and specifically regenerative braking. It works a hell of a lot better than brakes. But admittedly, we’ve never tried it going 50 mph on glare ice and suddenly deploying it. More likely creeping down an icy hill at 14 mph.

      We’ve had a particularly gruesome winter this year. But the way I drive on ice and snow does not precisely include 50 mph on glare ice. I kind of creep around carefully in like an Escalade that cost $59,000 to buy and probably $80,000 to actually convert by the time we did almost everything on it at least twice. Wrecking it on a bread run in bad weather isn’t really part of the game plan but indeed, I drove it more than I would have thought this winter. SImilarly the Model S.

      The part that always gets me is how you armchair theorists adopt such a SUPERIOR and indeed CONDESCENDING tone when delivering these little tidbits of safety and dire warning. How can you adopt such a tone with something you know absolutely NOTHING about?

      In any event, I suspect MOST of our viewers also hang out on DIYelectricJunk or EVILDEAL discussion group as well. Take it there and I think you’ll find a ready and appreciative audience for such nonsense. No point in gucking up our little comments section with it though.

      ” if you have rear wheel drive, you need to be careful about regen” this is of the nature of IF YOU HAVE and YOU BETTER. It’s a sure sign of somebody typing themselves smart SO they can offer condescending advice.

      We have two forms more popular here. “I did x and got Y as a result – anyone got a theory or use as you might” and inquiries of the form “when you did….what were your fiindings”. Quite a bit of “looky at what I found elsewhere online.”

      Most corresponding here do not condescendingly offer gratuitous advice to anyone. First, we’re not as sure of our position as you can be when it is all iimaginary. Second, it might not even apply to what they are doing even if we’re absolutely correct. It is unclear, for example, how your advice might apply to a tracked snowcat nevermind a boat. And what teh boat was doing on glare ice is not precisely any of our business. It was his boat and his ice.

      Please understand this is not really directed at you personally. I had SUCH a RED ASS on this topic that it was a huge leap of faith to even HAVE a comments section or a product support forum at all. It was years before anyone persuaded me of it. I consider such forums generally an absolute detriment to the cause and of doing greatly more damage than good.

      I assure you if I chose to do a general online forum such as DIYjunk or EVILDEAL, they woudl be out of business in 3 weeks. But I kind of suspect the nature of the medium itself attracts this kind of crap. EVERYBODY is an EXPERT and the posing and posturing are just beyond belief as each tries manfully to be more helpful (and more condescending) than the next.

      So we do videos and try to do more SHOW and less TELL and while we do editorialize endlessly, it is more or less clearly marked as “gratuitous opinion of the moment” rarely very strongly held and mostly offered as entertainment. ALmost everyone good naturedly disagreeing.

      Even to the point of obvious. If you dont want to wear safety glasses, don’t wear the goddamn things. They are YOUR eyes. We like to keep our pack from frame leaks and we do mention what the theory is if you have one – but it’s your car, your pack, and if you like to dance to the tune of 360 volts our story is “get down with your badself doing the MOTOWN thang.”

      Jack RIckard

      1. Dear Jack,

        Around these parts is very normal to drive on thick ice. We’d be stuck at home for at least a third of the year if we didn’t. Obviously proper winter tyres are compulsory, preferably studded. On highways the speed limit is only lowered to 100 km/h or 62 mph. Uncontrolled regen in these rather common circumstances would, in my humble opinion, make for an expensive mistake right away. My nearly completed EV is front wheel drive and DC only, so I can’t prove this myself. Then again I wouldn’t want to anyway. I could simulate it by pulling the handbrake at full speed, but I’d rather stay on the road. If someone does want to do it on their vehicle, he’s obviously welcome to do so, but hopefully not in traffic.

          1. Jarkko Santala

            All I’m saying is that it’s something to consider. Anyone is free to do as they please. Including turning off regen, which is simple enough. If I was building a vehicle using GEVCU I might ask for a way to turn off regen using a switch on the dash. Having endured a sideways mounted motor install on a front wheel drive vehicle I’m quite certain my next build must have rear wheel drive, so there’s a chance I’ll run into this at some point. I’ll be putting my current build into the database at some point, even though it’s not a classic design by any means.

          2. FIWI, I did lose control of my rear wheel drive car on ice one winter when I let up on the throttle completely. It was an automatic and the wheels were not allowed to rotate fast enough to match the speed of the car, ~25mph IIRC. Since it was my first winter driving after returning from Singapore I didn’t have the experience to realize that I would have regained control if I had given just a slight amount of throttle to get the rear wheels out of their sliding state. While reviewing the events that had taken place and coming up with the hypothesis of what and why things happened I did go out and test and verify the hypothesis later in similar conditions. If this is anything like what regent might do then it applies.

            In the case of my Gizmo, regen does cause the rear wheel to slide on wet or icy roads. The issue is exacerbated by the fact that I can only adjust max regen and min regen is 50% of max so there is no chance of “gentle” regen. I’m glad I have to manually request regen each time I want it for this vehicle.

            David D. Nelson

          3. In any event, we don’t have to wreck a car to make a change in the GEVCU software.

            It would not be terribly hard to implement this in GEVCU. Let me ask your opinion – which would be preferable:

            1. A digital input enabling/disabling REGEN. This is a 12v input so 12v would be disable and 0v being normal regen values as configured. Implies a dash toggle switch. But it is somewhat flexible. For example, whenever you turn on your fog lights – no regen.

            2. Use one of the unused analog inputs with a 5k pot to adjust regen from zero regen to max regen. Actually what I would probably do is a fully counterclockwise pot (lowest input value) would be regen as configured. Higher values would reduce regen to zero at maximum input. Fully clockwise.

            Jack Rickard

          4. Jarkko Santala

            Jack,
            I think a on/off-switch in the dash would solve the actual problem just fine. A simple pot might have the issue of accidentally touching it and thus a little iffy as a safe method for adjusting regen, if there’s a need to be able to switch it off completely. Perhaps a pot, which would lock in to off position or a round switch with a couple of positions like 0 for no regen and 2-3 different regen settings for the driver to choose based on his/her preference. It does get a little complicated though and personally I like to follow the KISS principle.

  11. Jack, Jack P does have a valid concern. If the braking force is aggressive enough to break traction on either or both axles it can lead to loss of control. Obviously, the less traction you have to begin with, the more likely it is that the wheels will break free. I use this method quite often on rain slick roads or on packed snow. Not so much on ice because the other axle doesn’t have sufficient traction to control the spin.

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