GM's new Volt

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The usual. As I have two large solar PV systems here, and my lab assistant just put one in, and others are interested in things like this, here's where that stuff goes. This is mostly for things that work now, not "gee someday a fusor will do this" -- we know that, but it's not someday yet.
The hope is to save anyone embarking on this sort of thing a lot of wasted time and money, as at least I have been off the grid since 1980 and have had a lot of practice (and made mistakes you won't have to).

Re: GM's new Volt

Postby Doug Coulter » Sun Nov 13, 2011 10:09 pm

Joe, since I have one now, we'll soon know what the heater draws. This thing is much more sophisticated than I'd thought as far as thermal management of everything goes. The gas engine can run on a cold start to generate heat for the battery pack! So can the A/C if things are needed the other way! IT has two liquid cooling systems, and evidently the cabin can be driven off either one, or electric heat. It has a bunch of possible settings for semi and fully automatic, with various biases, "save energy", "eco but you won't die" and "comfort". The recommend using the heated seats more than the other stuff to save power, and give various estimates in the on board displays saying what percent of the power is going to that stuff. The "worst" setting is 20%, then 13%, 9%, and none. But those could be "microsoft minutes" as far as I know. Evidently heat is basically free if any of the drivetrain is hot anyway, like any other car. But it's not a sure thing any part of the drivetrain will get hot - running pure electric seems to be the worst case for free heat.

It has a remote-start kind of thing, and if the heater was set on, it will use your house power to preheat it all before you get into the car. The thing is quite well insulated, and might hold that for awhile, dunno. It'll get the acid test here, fer sure, because I like it warm and it's going to be (already is sometimes) real cold soon. And heated seats ain't going to take care of my numb fingertips.

This actually looks like a practical ultra high gas mileage car if you never plug it in...interesting. It seems to be in the low 50's mpg running on the gas engine, but I've not run that enough to be sure - might be a resolution issue there. I went 10 miles on .2 gallon with it - but it's .1 gal resolution and 1 mile rez if I read this right. I tried putting down the hammer in it just today, after the batteries were at their low limit, with the gas engine running - zowie, this thing is FAST. I'll try it too with just battery, but the way it works, it should be the same, just ruinous to the battery range. Actually seems a little higher power/weight ratio than the Cruze, or maybe it just takes you by surprise better - no winding and howling and turbo lag and shifting, just GO.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: GM's new Volt

Postby johnf » Mon Nov 14, 2011 3:47 am

Doug
maybe you need the nickname
Voltdare
apologies to the electric frog
with the use you gave the Camaro selling it may have been a retrograde step for the planet
its probably in the hands of a young hoon now --depleting the world oil reserves and putting tonnes of carbon into the air everyday for no good reason.

As for the security screws your country is a bit backward --I had a devils own job to purchase a set when I was in Florida to service a density gauge we sold international paper for the Mc David mill --had to show my passport at Lowes to be able to buy --ie not out on the shelves like any hardware store here.
As for an alternative lifestyler you do put your money where your mouth is --better than 90% of the so called

I'll wait for updates
pity there is no sign of a right hook version
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Re: GM's new Volt

Postby Doug Coulter » Mon Nov 14, 2011 8:27 am

It might be, though of course selling the Camaro to the dealer means it's off the road for a bit, and with plenty of new ones, they might not sell it so quick. On the other hand, if as you say some punk gets it and thrashes the crap out of it - it'll soon be off the road permanently - that car was just too fast for a humans response time, and a low judgment level type of driver will quickly wreck the thing - and that's who tends to want those, guys lacking an abundance of restraint. One beer, you're dead, or it's almost like that. A neighbor bought one, it lasted less than a month.
He's alive (it's got a lot of intrinsic safety) but no more car.

It depends on the screws. Our big-chain hardware stores ARE backwards as heck, I call it the Wal-marting of the world, anything they can't sell in high volumes, you can't buy at all.
In the case of the security drivers and such like, I'd bet they don't even want to sell them and encourage people to be able to pick the locks as it were. However, the Chinese come to the rescue in the form of Harbor Freight, and any real machine tool seller has them - McMaster got them to my door in 23 hours from the order on the web page.
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Re: GM's new Volt

Postby chrismb » Mon Nov 14, 2011 8:31 am

Doug Coulter wrote:Evidently heat is basically free if any of the drivetrain is hot anyway, like any other car.


Just to warn you, Doug, both my current and previous diesel cars (gentle highway driving in the first got mid 80's mpg, this one does mid 60's) take around 18 miles before they put heat through the matrix off the engine. This is a real problem in winter driving as you don't get anything to de-mist. I believe the latest euro-diesel cars, which are more fuel efficient still, are trending now to have heating elements in the ventilation systems.

I had always presumed folks would start building in reverse air-con systems, but as far as I know this hasn't started happening yet. I hope they have been sensible enough to build yours with reverse ac.

On my regular commute, 22 miles, on leaving the car, the rear exhaust pipe is still below body-temperature to the touch.

Electric heating will hit the range, hard. It is surprising how much heat power you need to keep a car warm enough, especially relative to the drive-line efficiencies they'll have built into that car (it probably only uses 5kW to keep moving at 40mph, or more, about the same power you need to ensure the car is heated to 'nice-n-toasty'.)

So in winter months I used to take my wife's thirsty Subaru, just so I could burn >2 times as much fuel to stay warm!!! But we sold that and she's got a diesel too, now. I put a 2kW fan heater in my car for a half-hour before setting off, once it drops below 4C outside.

It's great to run fuel-efficient cars, but this is the one big down-side!
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Re: GM's new Volt

Postby Doug Coulter » Mon Nov 14, 2011 8:54 am

I absolutely agree on the heat issue, though compared to most cars, this one really went all out on insulation and low thermal mass in the cabin, so it might be a *little* better - still has tons of glass, though. I have that issue in the Cruze - it takes forever to warm it up unless I chose the path out of here that's uphill for the first few miles and then drive it hard. The heated seats are a sweet thing to have to be sure, but it doesn't fix the nose or the fingertips. I believe the Volt does do heat pumping (including doing the battery temperature control), the book seems to say that (the "trained" salesmen don't know much). I'm just going to have to put this up on the lift and look for myself.

It does have a feature to "remote start" and heat itself up whilst still mains-connected, but electric heat is the expensive sort even if you have power company power, and kinda lame here where it's not so readily available. Maybe I'll hang a propane lantern in the back...It has the usual electrically conductive glass (and heated mirrors) for that kind of stuff. Usually not a huge problem here, where I rarely bolt out of the house in early morning. If it's thick snow/ice, it's going to be the truck anyway - or sit back and enjoy the show till someone needs a rescue.

This sort of thing I'll just have to do the user-test on. Heated seats in this (or the Cruze, which I might now sell too) vs taking a long time to warm the cabin, or the lack of them in the truck, which warms the cabin RIGHT NOW (well, about a mile), but lacks the nifty seats - the other side of the nasty gasoline mileage it sports.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: GM's new Volt

Postby Doug Coulter » Mon Nov 14, 2011 8:06 pm

Found out some more info on all this, and took another long drive and learned some tricks. First, when the car is plugged in, it does some work to maintain the batteries in a narrow temp range. If you remote-start the car, and have the other junk set up, it will warm the car cab up on house power, which is a good place to start (it will also run the defoggers). The heated seat doesn't use diddly battery power. The heater might if it's in pure-electric mode. The info screen says it can eat almost 20% of your range in full comfort mode (it has a try, but not too hard mode too, called eco that uses about half that).

In normal driving mode (of the three, normal, sport, mountain) you get an engine start with about 25% of the battery left. That's because the engine is only 84 hp, but the electric motor is more like 150 (267 ft lbs torque!). So you need to have some battery for peaks, or it would drive lame (it hasn't driven lame for me at any time, and that's why). "Mountain" mode "reserves" more battery in anticipation of a long grade climb coming up. The net effect of this is it will switch to gasoline at about half charge, and use both thereafter as needed. This can be used to get right about half a charge on the main battery even from "zero" by just driving it in mountain mode, which I did tonight - and I got 48 mpg doing that (engine running the whole time), and got home with half a charge - same as I began with (not running the climate stuff, it was nice out). Sport mode allows for more peak drive power, like you'd expect, but doesn't change the "reserve" for peaks like mountain mode does.

Looks like this thing probably gets 35-40 mpg on IC engine-only with climate control maxed out, from the discussions. That's a good bit better than the 34 the Cruze gets, or about 33 with the A/C on.

Other than climate control, stopping doesn't cost you anything - it turns off like any car. Idling - it doesn't do that, it just shuts off (the IC engine does too). Reheating the car after a stop (unplugged) would probably eat range. But plugged in, it will keep itself heated and so on from the plug power. And if some is left over, also charge. I get the idea that the heater is on the weak side in pure electric from the discussions. We'll see. It is in the Cruze, as is the A/C in that - just tiny stuff but still a car to heat, one step away from trying to condition the out of doors.

So the mountain mode is a kind of nifty hack that lets you keep at least 50% charge on the thing if you're demoing it all day - that's plenty to demo the pure electric mode, then put on mountain mode and the IC engine will get you back to half charge. I found that you can do somewhat better than that. I can come home from town more than one way, and the way I came you climb to the top of the mountain before coasting back into my place, and you coast for miles. With mountain mode on, you get regen braking doing that few mile coast, and it's enough to add a couple miles to the battery range from that.

Someone mentioned they get IC engine running at speeds over 75 mph. I just recently found the screen that shows all that (in the videos). Without that, you can't tell! They limit peak battery current, so the IC engine will cut in for super high speed cruising to help provide the vastly increased power need for going real fast and fighting the wind.

I found out IBM wrote this software - it's slick. A lot of people are complaining about the Ford stuff, which is Microsoft. Somehow, I'm not surprised.
This thing looks really well thought out so far - everything I've thought it should do, it already does, it's mostly a matter of understanding (or just finding out how to get it to tell you what it's doing now), maybe giving it a hint.

What I am surprised is that none of the demo vids I've found on youtube are even as impressive as my climbing of the hill from hell, and accelerating to over 75 doing it. And heck, that wasn't even in sporty mode -- I'm going to have to try to do a burnout in that mode with the traction stuff turned off. I have gotten the tires squealing on a hard left across traffic already, from a standing start - it really jumps off the line. This might just light them off and get me some smoke!

Since I got back home tonight with half a charge (burned a whole half a gallon of gas for the round trip in mountain mode, and not driving easy either, just my normal 50+ in a 35 zone), which is also about what I get from a decently sunny day, just turning on the charger *after* the house batteries are full in low use mode (stock trading with a computer and a light and the freezer/stereo running) - I should be able to get full charge on any good day, starting from there. Or two days starting from nothing (with my good panels still on the ground in the garden, where they are shaded most of the day). I suspect it's going to get better once I get them up in the air, a lot. I think this is going to work out great, and I'm planning on selling that Cruze, which I actually liked better than the Camaro as a daily driver. I just won't need it anymore (or the property taxes and insurance costs).

Oh, if it's dead cold - it's been parked overnight outdoors in 20f kinds of temps, it will always start the IC engine to heat the *batteries*. At that point, the cabin heat comes along free. But it looks smarter to keep it in a garage, and/or use the remote start and preheat off the house power (if you have it, in my case, nope). I'll probably put that coleman propane lantern in the back for preheat the cabin this winter or something like that. oohh, I have a neato wall mount gas lantern I'd bought for the van, but never installed, thinking "camping light and heat". It's cool looking and sips the propane. Now that would be a really anacronistic (but hey, romantic) touch in there...I even have a tiny propane tank (thanks to Bill finding it, unasked for) that will run it for a looonnng time - about the size of a big cantaloupe. And yes, Bill, they filled it the other day, no questions, leak tested it free for me. Cool! (or in this case, HOT).


Here's a link to a forum of owners and GM guys where I learned some of this:
http://gm-volt.com/forum/index.php - I'm DCFusor there, and will probably post some stuff.

And a little vid on the climate options:
http://www.youtube.com/watch?v=Hs7XChUL ... e=youtu.be

None of which I've yet tried, weather's been nice, so I'm going around in fan-only or windows open. For now, I'm trying to get to full charge off the solar alone, no backup generators or anything. Matter of honor to see if I can.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: GM's new Volt - the hidey hole

Postby Doug Coulter » Tue Nov 15, 2011 2:44 pm

Ah, thanks to youtube and instructional videos for first responders, I've learned a few new things. You can get to the main 360v raw from the center console - the tray lifts out (no tools) and there it is if you're feeling suicidal. But the real key to hacking this thing is in the pix below of what's under the deck in the back (4 nuts to remove).
Volttrunk.jpg
Under the deck under the lift up panel...

Took two pix, the one above holding the camera over my head didn't get the battery all the way, here's another:
VT2.jpg
Another view


According to the GM volt forums, this 12v battery and charger are the keys to the kingdom - all the control stuff runs off this. At the top is the huge switching supply that keeps it charged off the main traction 360v battery. It's rated at 175 amps output at 14.4 volts. So the 12v battery pictured is just a bypass capacitor for peak loads larger than that. If the car is "on" the IC engine will fire up if the main traction battery gets too low, and thus keep this charged forever. So, the upshot (according to GM) is that you can eat all the power you want off this 12v battery and not screw up the main monitoring systems and so forth - they had kilowatt stereos in mind, but...that's not the only possibility. I see Harbor Freight has a 1.2kw inverter for $109 that will fit nicely in there in front of the battery, nice short wires to it if I can figure out how to remote the power switch and outlets (oh wow, how will I ever manage that? ;)

Since mountain mode will run the IC engine to keep that main battery at no less than half charge, we now have a way for this to backup my solar system for the house - just plug a plain jane charger in to an inverter here, which of course would not be the only possible use of such a thing. Now that's cool.

I see a rather large centrifugal fan there, pulling air through the switcher and then out over the battery - they thought ahead here, but not too much - else there wouldn't be as much spare space as there is, and there's plenty even when avoiding the dimples in the charger and tire compressor holder above this. The door over those is magnetically latched, shades of Apple (or my own house kitchen cabinets, years before Apple "thought of" that one). Obviously it will be pretty straight forward to install an inverter here and do a nice clean job. There are openable side panels in the fascia just above this I can install outlets from the inverter in as well, so as not to have to move any cargo and lift the door to use it for a real clean, useful installation here.

So, looks like what could have been a major hassle, isn't. I can tap this real easily, and I just happen to have a current-limited 800w ferroresonant battery charger I built for that little Honda generator that can work with this. It's wimpy, but enough in a pinch, which is the use case here. The Volt battery has about 16khw in it when full, about 8 when at "moutain mode engine cuton" level, and will discharge down to 3.2 kwh before the engine comes on again for a useful amount of power of 4.8 kwh - that'll be fine, that's more than I use normally in a day in the house anyway (unless long fusor runs are going on).
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Re: GM's new Volt - new drivetrain info

Postby fusordoug » Wed Nov 16, 2011 8:35 am

Well, like in politics, things weren't just as advertised. No explicit outright lies, but the devil is in the details. It turns out that in certain modes, yes, there IS a direct connection from the IC engine to the transmission. It's actually a pretty complex system here, and frankly, it better satisfies my inner geek than what you'd guess from the advertising. There is a planetary gearbox, 3 clutches, two electric motors, one IC engine, and just about any combination of these can be connected to the wheels and each other - but not all at the same point in the ring-gear system. This is pretty neat, actually. I thought it important enough to increase the attachment size limit for the board (one of those 4 page word docs that's all high resolution images), but even then it wouldn't take it and barfed the server, so I put the doc in the library - warning, it's 13 megs. (I also made a start at updating some stuff in the detector part of the library)

http://coultersmithing.com/data/DataShe ... e_Unit.doc

The upshot is yes, the Volt is always electric - at least one of the electric motors is always driving the wheels. Sometimes both of them (one can be the electric generator instead) and sometimes everything is driving the wheels! But not in a simple one input, one output transmission, oh no, it goes much deeper than that. It seems that when the IC engine is clutched to the wheels, there is also one (or more, haven't figured all the details myself yet) electric drive motor coupled in - to a different place in the ring gear assembly, and any engineer would guess that this lets the IC engine just sit there at one RPM and do grunt torque service, while the electric provides the responsiveness, allowing the IC engine to not have to shift its operating point as speeds and demands change - they claim this is a MAJOR source of more efficiency, and I believe it - always better to avoid extra conversions from shaft power to electricity and back.

I never noticed it doing this - but now I'll try and see if I can. The only time you feel this thing "shift" is when you shift it with the shifter. Seems like the IBM software is taking maximum advantage of the fact it also controls the electric motor to make the shifts seamless - there is also no feeling of clutch slippage - there's just no feeling. The only reason you downshift is to get more regenerative braking say, in the last 100 yds or so of a long steep hill with a stop sign at the bottom - it's pretty serious when you downshift at speed (just like with any car), and saves braking effort while really pumping up the battery. It's better all round than really having to plant your foot in the brake pedal (which works fine, but this gets you charge back better and saves wear on the pads - energy back to batteries instead of heating the rotors). For more normal situations, like coasting up to a stoplight, light braking with the brake pedal gets it done well enough, so you're not really doing much extra manually. 1/4 G downshift braking down a steep hill adds nearly a mile to your battery charge...
Why guess when you can know? Measure!
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Re: GM's new Volt

Postby chrismb » Wed Nov 16, 2011 9:36 am

Sounds like the Prius topology.

It uses an epicyclic gear to 'add' the outputs of the engine and a high-geared motor. The outcome is that the torque of the IC can be balanced with the torque of the motor by choosing the gearing and speed. So you can keep the engine speed constant by changing the speed of the motor, or vice versa, or whathaveyou. It is an example of using the epicyclic as a 'difference engine' using epicyclic gears as the differential.

The Prius also uses the Atkinson cycle for improved efficiency (but is less-good as a direct-drive IC due to its characteristics). Not sure if this is using the Otto or Atkinson?
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Re: GM's new Volt

Postby Doug Coulter » Wed Nov 16, 2011 9:51 am

I'm not sure of your terminology here, but yes, it seems the electric motor handles quick changes, and the IC motor slow ones in this mode where both are used. That would give the IC engine time to do that cam-timing adjustment thing, not waste "accelerator pump" type gasoline for surges, and generally be a baseline shaft power source. I've just heard it run at all once, on the last trip, and while it does change with the throttle input there is a really big lag (second or two) speeding up, slowing down, and in how hard its working generally. I'd guess that when the system finds itself with too much IC output, it simply converts some of that back into electricity in the battery while waiting for it to slow down due to less computer throttle to it. But I thought it was cool to be using more than one "input" shaft to the tranny - a three shaft total, with energy being able to go in or out of any of the three in any combination. Those "shifts" are so smooth - one wonders if the clutches are binary or slipping types. It might just be very low electric armature inertia combined with really good computer rev matching and a binary clutch? Now THAT would really get my inner geek happy - a binary clutch could live a lot longer...

I'm just going to have to start driving this a lot more in the various modes and see what I can feel it doing as I get more used to it - everything is so much quieter and smoother than any other car I've driven it tends to be below my learned thresholds of detection. For better or worse, the next set of tests will be electric-only since I have a full charge, and I want to see what numbers I can get driving it normally, rather than the thrash testing I've been doing so far (which gives pretty good numbers anyway, I'll get a screen shot and post here). Once I run off that full charge, I'll try more brutal stuff. I have the feeling that in sport mode, and the traction control off - it'll spin the tires in a straight line launch from zero...gotta get that if it'll do it! It'll surely zizz them fine on wet pavement, no question (which is what we have here for a few days).

The other news is I've been reading their entire forums, and looking for troubles people have had with this and with rev-1.0 (I have rev-2). There's really not much, the usual teething stuff it seems. Bodes well.
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