OvermodEven the current battery chemistry and structure used in Semi batteries has nothing to do with that in current 12V batteries. Note that even in locomotive batteries, the preferred Siemens supplier only started offering Li-ion construction in late 2017.
I was thinking more along the line of a limit to number of charge/discharge cycles, regardless of the technology.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
tree68I was thinking more along the line of a limit to number of charge/discharge cycles, regardless of the technology.
This is likely with any high-energy battery chemistry, but I think the Semi people at Tesla will have very good extended data on practical cycle lifetime, specifically including real-world discharge cycles and consequences of real-world Megacharging. I don't really know from the published hype whether they are supporting a kind of modernized 20%-60%-20% rule to minimize the life of the strings (no discharge beyond 20%, no fast charging above 80%) or have just jiggered the equipment to charge "400 miles" equivalent in 30 minutes time. You will want to maintain some margin for non-damaging regenerative charge on a 'full' battery for more than the usual automotive reasons.
The thing is at least with an ICE if we lose say a turbo we can still limp along. With an electric truck that main propulsion unit fails your stranded. Also how is Tesla going to handle the on road recharge needs of these trucks. Just finding a parking space in a truckstop can be hard enough. The test truck video shows their driver has to drop the trailer to get to the supercharger. That is not going to work in the real world enviroment. Why a little thing called cargo theft. If your having to bobtail 200 feet away from your trailer at night to recharge in an unsecured lot your begging to have a load stolen.
I didn't claim to be in the equipment purchasing loop, it's too bad that drivers aren't involved more, we see all kinds of issues that often wouldn't even add any expense, but could improve either Safety or productivity, but those that "Know Better" all to often don't listen to those using the equipment to earn them money.
I never said that the status quo shouldn't change, but from what I have seen, the EV technology isn't even close to being ready for the large CMV market.
Doug
May your flanges always stay BETWEEN the rails
Shadow the Cats ownerAlso how is Tesla going to handle the on road recharge needs of these trucks.
I predict that trucks with large generators will be assembled and used by the wrecker operators for just that purpose. For a price, that is.
Which begs the question - how many KwH will it take to charge one of these beasts. Per https://www.eia.gov/electricity/state/ , the national average is 10.26 cents per KwH. California and New England are in the 15 cent range, and Hawaii is 23 cents.
A commercial vendor (ie, gas station) is going to add a finagle factor. Trucking companies and outfits like WalMart can just tack the usage onto their regular facility power and perhaps catch a break.
challenger3980I didn't claim to be in the equipment purchasing loop, it's too bad that drivers aren't involved more, we see all kinds of issues that often wouldn't even add any expense, but could improve either Safety or productivity, but those that "Know Better" all to often don't listen to those using the equipment to earn them money.
And you know what? You drivers will make it work, and make it work well. And the bosses will look good.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
tree68Which begs the question - how many kW/h [note sp.] will it take to charge one of these beasts.
The charge rate is more important than the transfer of kW/h. Tesla's initial answer is about 1.6MW (average over the 30 minutes); ChargePoint's rate (in May of this year) is 2MW. Both involve, as I noted, charging in parallel, and at higher service voltage.
Expect a substantial utility branch to each 'equipped' truckstop, as upward of twice the number of "stalls" will be required to service the same level of traffic (the baseline rapid charge discussed takes about twice the time of a diesel refill). But not particularly impossible, especially if (as I expect) various government entities provide incentives to provide the incremental infrastructure by region.
Overmod I don't really know from the published hype whether they are supporting a kind of modernized 20%-60%-20% rule to minimize the life of the strings (no discharge beyond 20%, no fast charging above 80%) or have just jiggered the equipment to charge "400 miles" equivalent in 30 minutes time.
I don't really know from the published hype whether they are supporting a kind of modernized 20%-60%-20% rule to minimize the life of the strings (no discharge beyond 20%, no fast charging above 80%) or have just jiggered the equipment to charge "400 miles" equivalent in 30 minutes time.
The 20%-60%-20% rule is a simplification of the problem (though a reasonable and useful one). The big weakness with Li-on is with >80% state of charge and battery temperatures greater than 40C the battery lifetime is dramatically lowered. My recollection was that high battery temps were still life limiting at lower states of charge but not to the extent as above 80% SOC. This suggests that the Tesla Semi may not be the best choice for Lost Wages or Phoenix in the summer.
zugmann challenger3980 I didn't claim to be in the equipment purchasing loop, it's too bad that drivers aren't involved more, we see all kinds of issues that often wouldn't even add any expense, but could improve either Safety or productivity, but those that "Know Better" all to often don't listen to those using the equipment to earn them money. And you know what? You drivers will make it work, and make it work well. And the bosses will look good.
challenger3980 I didn't claim to be in the equipment purchasing loop, it's too bad that drivers aren't involved more, we see all kinds of issues that often wouldn't even add any expense, but could improve either Safety or productivity, but those that "Know Better" all to often don't listen to those using the equipment to earn them money.
The productivity aspect doesn't bother me as much as the Safety aspect does.
a Perfect example that would cost NOTHING, but effect both Productivity and SAFETY, is where the DEF tanks and Chain Hangers are mounted, defying logic, it seems that the default layout is to mount the DEF tank on the passenger side, while 90+% of fueling staions only have DEF pumps on the Drivers side, inconvenient but can be managed.
Now the Chain Hangers being on the Drivers side, IS a Safety issue, obviously if a Driver is needing the chains the road conditions are BAD, and the Last thing you want is the driver being on the TRAFFIC side of the vehicle any more than absolutely neccessary. You HAVE to be on that side to chain the tires on that side, but there is NO reason to be on that side when removing the chains from the hangers, or returning them to the hangers, it just puts the driver in the "Danger Zone" longer than neccessary, and to reverse the positions of the tanks and hangers would cost nothing.
I have addressed this issue with management, but I still see new trucks delivered this way, I wish I knew how to communicate this thought to the MFR's.
erikemMy recollection was that high battery temps were still life limiting at lower states of charge but not to the extent as above 80% SOC.
You are correct, of course, and if you're wondering why Tesla has gone to active cooling this would account for it. I do ASSume that the Tesla Semi battery design has incorporated both regular and emergency cooling and that the energy involved in providing this cooling is accounted for both in the overall heat dissipation and the parasitic losses affecting range.
Keeping the battery WELL away from any degree of internal heat anywhere in the battery structure that might lead 'weakened construction' into thermal runaway is a very important operating criterion...
My biggest concern is how is the battery pack on one of these things going to react to some of the hazards that OTR trucks hit and they go under instead of over the vechile. Things like deer other smaller game. How well is it going to stand up to an elk or moose.
Shadow the Cats owner My biggest concern is how is the battery pack on one of these things going to react to some of the hazards that OTR trucks hit and they go under instead of over the vechile. Things like deer other smaller game. How well is it going to stand up to an elk or moose.
Don't forget segments of broken leaf springs that get kicked up by the tires and other things like retread treads kicked up by the tires as well as other sizeable highway junk.
Never too old to have a happy childhood!
BaltACD Don't forget segments of broken leaf springs that get kicked up by the tires and other things like retread treads kicked up by the tires as well as other sizeable highway junk.
Yep, That driverless truck is going to be out of the cab, Fire Extinguisher in hand in a Flash to put out that Battery, Tire or Cargo Fire, Ohh, never mind the Fire dept. will be there in 20-30 minutes depending on where in the middle of nowhere it happens right?
challenger3980Yep, That driverless truck is going to be out of the cab, Fire Extinguisher in hand in a Flash to put out that Battery, Tire or Cargo Fire, Ohh, never mind the Fire dept. will be there in 20-30 minutes depending on where in the middle of nowhere it happens right?
My husband still has freaking nightmares 20 years later about the accident he witnessed in Wyoming. Kid 18 years old riding with a helmet but no other protective gear on a crotch rocket. Well he hit some sand left over from the winter on the shoulder on the road. The kid peeled himself like a banana doing 80 on the interstate. The closest Ambulance was 45 mins away closest WY state trooper was 35 mins away. The kid died from his injuries in 33 mins according to my husband who remained there trying and failing to stop the bleeding. Yeah that would be a fun area for Tesla to meltdown in.
Balt, I'm sure the point of the post with the video is that a Fire Extinguisher isn't adequate for all situations, but in Many situations a Fire extinguisher used in a timely manner CAN be the difference between a small mess to clean up, or Interstate closed for hours, or even a 50,000+ acre Forest fire, think Eagle creek fire in Oregon 2017, a Dumbass with a Smoke Bomb, That scorched an Amazingly Beautiful area, and had I-84 Closed for 6 WEEKS, right when it happened a fire extinguisher may have stopped that completely.
I have Personally used a Fire extinguisher from my tractor twice to stop fires while they were still small, before they got out of hand.
The first time was at a Burger King restaurant in Woodburn, OR. while delivering the female manager asked "When you get a chance, can you give me a hand?" So I'm thinking small gal that she was, she needed a heavy item off a shelf. I follow her over to the fryer banks, she opens up a door to one of them, and it is on Fire around the gas line and control panels, Dayum was she Calm about that. I grabbed a fire extinguisher off the wall, Shat, it's EMPTY, I ran out to the truck and grabbed the extinguisher from the tractor and put it out. That easily could have engulfed the whole building, if left unchecked.
Another time, I was westbound on WA 512 approaching I-5 in Lakewood, WA, and I could see flames dropping under a car on the shoulder, with it's Hazard Lights on. I stopped and grabbed my leather gloves and fire extinguisher, the driver was still IN the vehicle, I told her to GET OUT, shut the engine OFF and release the hood as she did so. She had a ruptured fuel line. I was able to put the fire out, and stayed with her until the Fire Dept. arrived, I'm sure the car was totaled any way, but it could have been a much worse situation.
A Fire extinguisher won't be able to stop every fire, but there is a REASON that they are required in all CMV's, and Locomotives too, IIRC.
challenger3980 Balt, I'm sure the point of the post with the video is that a Fire Extinguisher isn't adequate for all situations, but in Many situations a Fire extinguisher used in a timely manner CAN be the difference between a small mess to clean up, or Interstate closed for hours, or even a 50,000+ acre Forest fire, think Eagle creek fire in Oregon 2017, a Dumbass with a Smoke Bomb, That scorched an Amazingly Beautiful area, and had I-84 Closed for 6 WEEKS, right when it happened a fire extinguisher may have stopped that completely. I have Personally used a Fire extinguisher from my tractor twice to stop fires while they were still small, before they got out of hand. ... Doug
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Simple fire extinguishers don't seem to handle a semi that had one of it's drive axles become detached from the truck and it then impacts the concrete end of the bridge it was crossing at the time resulting in the tractor and trailer going off the side of the bridge into the 'flood plain' below the bridge and catching fire with all the fuel spilled from the rupture of one of the fuel tanks.
Yes fire extinguishers are required for trucks and trains - but fires can easily be beyond a extinguishers capabilities. I carry a fire extinguisher when I am loaded on a racing trip and have had to use it one time to assist another person at a fuel stop.
But they can keep a simple tire fire from engulfing a fuel tanker if stopped soon enough.
Just as you wouldn't use a 3/8 drive ratchet to build a Bridge, there are plenty of uses for a 3/8 drive ratchet, every tool has it's uses and limitations.
I keep several 3A,40BC extinguishers in the house and gargage, as well as one in the pick up. Like a Seat Belt, Motorcycle Helmet or Life Preserver on the boat, they are things that you Hope you never need, but when you do, Nothing else will suffice.
All our trucks have 2 on them a 5 lb ABC dry chemical in the sidebox. Then a 30 lb CO2 strapped next to the drivers access steps on the frame. The 30lb ones we hope never have to be used as when they are used it was a lfe or death situation that required it. Those are there for when our drivers come upon an accident and they might need the heavier blast to stop the fire to save a life.
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