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Tesla Semi’s Enormous Battery Might Weigh 11,000 Pounds on Its Own
- moistly 4y agoWhen one of those inevitably goes up in flames, it is going to be hella impressive.
- nwmcsween 4y agoSo, the big issue everyone seems to be ignoring here is momentum and control, controlling a 20,000lb tractor is going to be hard and incredibly dangerous in bad conditions.
- 0wis 4y agoIs it really a problem ? I mean, apart from the quantity of lithium needed to create this « enormous » battery, is weight a real limitation factor ? We currently have no info on the full truck weight but I am sure Tesla found ways to optimise weight everywhere else. Mechanical components for a 1000000 miles rated vehicle are heavy and without a gearbox and a crankshaft, I assume the rest of the truck is lighter than its gas counterparts. I am no expert so maybe we are dealing with other orders of magnitude. Anyway, would this impact the maximum cargo weight ?
- cheaprentalyeti 4y agoSpeaking as a former shipping and receiving guy, well, yes. It suggests some 11,000 pounds less capacity on a standard semi, which are highly regulated as far as maximum weight/mass goes.
- bombcar 4y agoYou can make some of that back by the removal of the engine and fuel (though you still need something akin to a motor and perhaps a transmission). Likely parts of the truck will have to be converted to aluminum - perhaps the trailer itself. A full semi can have 300 gallons of diesel which itself is about 2000 pounds, so we're down to a 9,000 pound difference. And some percentage are short haul, which are often not even near to fully loaded. Could be as high as 40-50%.
- ggm 4y agoA semi weighs between 10,000 and 25,000 lb. A semi's ICE engine weighs around 3,000lb. I don't work in the industry. I just observe three things: 1) the weight variance of a semi encompasses the amount imputed to the battery 2) 3,000lb of weight can be saved by not having a diesel engine plus another 2,000lb not having fuel. (Both of which will be in the total gross weight of the semi) some of which will of course be replaced by electric motors. 3) it's a speculative weight. It might also not weigh that much. Might is doing a lot of heavy lifting. A fourth point: trucks routinely travel partly empty because of weight distribution issues. Not every TEU is full. Logistics is fascinating. TCO is the closest most computer scientists get to "how can owning a Mac be cheaper than owning a Windows PC" but logistics does this almost every sum. Weight and carry capacity may not be the sole deciding factor here when a semi is worth $500k and has a 2nd hand value and is a finance decision with tail costs and operation costs.
- Robotbeat 4y agoExcept the vehicle has made weight reductions elsewhere, including engine, transmission, emissions control, fuel tank, etc. A typical useful payload is around 44,000pounds still keeping under the 80,000pound limit, and the Tesla Semi was able to do that (electric trucks are allowed ~2000pounds extra).
- simonebrunozzi 4y ago2,000 extra pounds for electric vehicles.
- Arrath 4y agoThough I only gave it a quick search and it seems annoying difficult to find straightforward spec sheets for semi tractors like you can for any piece of CAT equipment, [0]"As we highlighted above, there are several ways to measure a semi-truck’s weight, and the maximum legal weight for a fully-loaded semi in the United States is 80,000 pounds. The lowest unladen weight is roughly 25,000 pounds, but will typically be closer to 35,000." So, 10,000+ pounds for the power pack alone is a sizable chunk of the maximum allowable weight, and could potentially eat into the allowance for cargo, more so for restricted routes like older inner city bridges with tight weight limits and the like. [0]https://www.jdpower.com/cars/shopping-guides/how-much-does-a-semi-truck-weigh https://www.jdpower.com/cars/shopping-guides/how-much-does-a...
- theRealMe 4y agoI’m curious how often fully loaded semis hit 80000 lbs. a quick google seems to show me maximum capacity instead of average/median weights…
- dsfyu404ed 4y agoAny time you see a trailer that carries some sort of bulk good it is safe to assume that that trailer is right at the max weight.
- cannaceo 4y agoAgricultural products, heavy equipment hauls, bulk materials, etc. regularly hit 80k pounds and above. Truckers picking routes to bypass scales is a meme for a reason.
- Arrath 4y agoNot at all uncommon, though my experience is with equipment rather than general containerized or palletized cargo. e.g. a CAT D8T bulldozer weighs in at over 80,000lbs all on its own and they are often trucked around as a complete unit, so you're looking at 20-35,000 more for the trailer and tractor to haul it. Heavier pieces of equipment like D9's (108,000#) or D10's (145,000#) are generally 2-3 loads of chassis/tracks/blade&attachments.
- dark_glass 4y agoThe Youtube channel Engineering Explained went over the Tesla Semi, and the weight of the EV cab should be pretty similar to an ICE cab. Also EV trucks are allowed another 2k pounds. https://youtu.be/Uv44W7xa4IU https://youtu.be/Uv44W7xa4IU
- AareyBaba 4y ago"Also EV trucks are allowed another 2k pounds" - Ah that explains the 82,000lbs mentioned in the Tesla demo. Max weight for conventional trucks is 80K. There were about 10-12 concrete barriers as load in the demo each weighing 39,000lbs. So the weight being carried is around 40ishK lbs. So rough approximation - half the weight of the truck is load and half is the truck itself.
- saalweachter 4y ago> ... but I am sure Tesla found ways to optimise weight everywhere else. This is kind of a "the entire industry is dumb" assumption. I mean, sometimes industries are dumb, and there are certainly people driving oversized vehicles on the road right now, but if you can find places to optimize vehicle weight outside of the engine/transmission/fuel you're replacing with batteries/motors, that applies to regular old semi-trucks; if you can make a semi-truck weigh 5000 lbs less without compromising on its design parameters, you can make every other semi-truck on the road more fuel efficient and save like 6% of your fuel costs, while also allowing you to haul bigger loads than competitors' trucks. Everyone making semi-trucks is interested in that, not just Tesla.
- bryanlarsen 4y agoEverybody else is using a chassis designed for ICE, so something that handle a vibrating 5000 lb engine, a vibrating 1000lb transmission and can hang 2000lb in fuel. They then need to add reinforcement to hang a 10,000 lb battery. I'm fairly confident some of the rest of the industry could get a comparable weight if they started from scratch and they optimized for EV only. But that's two assumptions that don't currently hold.
- mjevans 4y agoHot swap and multiple sizes (weights) of battery would be very killer features. Fleet vehicles like this are exactly where it makes the most sense to have a stop and swap strategy for refueling, especially when so much energy needs to be transferred at once. Though that is lessened by the size of the battery since they could argue it gets recharged during a mandatory rest period.
- msandford 4y agoSeems like it would probably be a bigger win to put a 100kwh pack in and create a modular generator package. A lot of the polluting big rigs do is particulate matter when accelerating. Using batteries as the buffer between power generation and power consumption would do a lot of good. Being able to run different kinds of small 20-80hp generators at their max efficiency RPM would be great. And if it were a reasonably sized module different folks could compete to make different highly efficient generator packages running on gas, diesel, CNG or LNG, ammonia, DME, hydrogen, ethanol, or whatever.
- dogma1138 4y agoThere are a few startups that are doing carbon capture for trucks the closest to a market solution is probably https://remoracarbon.com/ https://remoracarbon.com/ they also have an interesting business model where they offload the CO2 and sell it off and have a profit sharing with the truck/fleet operator. It doesn’t solve all emissions problems like NOx and other particulates but it’s a good step and likely we will be seeing both electrified trucks for short hauls and carbon capture for long hauls and for more efficient reuse of existing vehicles.
- LinuxBender 4y agoI think you are describing a hybrid. The power company at my previous location had hybrid rigs for working on high voltage [1]. There are also hybrid fire engines. [2] [1] - https://www.pge.com/mybusiness/environment/pge/fleets/ https://www.pge.com/mybusiness/environment/pge/fleets/ [2] - https://chargedevs.com/newswire/los-angeles-fire-department-unveils-hybrid-fire-truck/ https://chargedevs.com/newswire/los-angeles-fire-department-...
- Robotbeat 4y agoNo? A hybrid powertrain is really expensive by itself, requires a more expensive-per-kWh battery pack, and has little efficiency advantage over an optimally geared Diesel engine in cruise, as it’s already running optimally. And you’re only making a marginal improvement in CO2 emissions. All the synth fuels are much more expensive than electricity.
- jjtheblunt 4y agoI wonder if hydrogen fuel cells driving electric motors would work in this case.
- Robotbeat 4y agoYes, but the range wouldn’t necessarily be better. IIRC, the Toyota hydrogen semi has a range of about 300 miles. And very little fueling infrastructure (with extremely expensive fuel). EDIT: yup: https://www.hotcars.com/heres-what-you-need-to-know-about-toyotas-hydrogen-electric-semi-truck/ https://www.hotcars.com/heres-what-you-need-to-know-about-to... Also, it’d require dumping a lot of heat. I talked to a contractor who once helped make the Nikola One heat exchanger, and he said it took as much power as a Nissan Leaf powertrain just to cool the dang thing.
- jjtheblunt 4y agooh that's super interesting. thanks!
- Robotbeat 4y ago11,000pounds for a battery implies 170Wh/kg. High end lithium ion cells can do about 300Wh/kg, and even with some overhead for the battery, we’re talking 250Wh/kg.. So… That’s beatable, & we can’t back out the weight directly from the energy of the pack as we know Tesla has been working on improving chemistry and specific energy and pack efficiency. Anyway, the claim by Musk that they can achieve 1.5kWh/mile is reasonable, and fits in with my calculations here: https://selenianboondocks.com/2017/11/tesla-semi-part-1/ https://selenianboondocks.com/2017/11/tesla-semi-part-1/ The vehicles that they delivered did not use all the available aerodynamics tricks that their prototypes did, and uses duals instead of super singles, so it also makes sense it’s only achieving 1.7kWh/mile right now. Note that a ton of people claimed a 500 mile electric semi with a full load wasn’t feasible. This proves that it is. (The jersey barriers they pulled weighed about a standard 44,000pounds.) The Toyota hydrogen semi has only about a 300 mile range and with fuel an order of magnitude more expensive.
- reportingsjr 4y agoYou're talking about battery cells, but you need to look at the battery _pack_ energy density. The model 3 battery pack, which uses the same cells as semi, is about 170Wh/kg. The numbers in TFA are very reasonable estimates.
- Robotbeat 4y agoI already addressed that by including mass overhead for the overall battery. And sure, it’s always possible to assume more conservative numbers for a whole battery and assume Tesla DIDN’T do any engineering work to reduce overall battery mass, but that’s not something you should put in a headline. (Tesla has typically done better than their peers in overall battery specific energy as well as energy per mile.)
- 0_____0 4y agoYou're using a 16-17% figure for packaging overhead? That's low. Even with relatively expensive construction techniques (for example if you're doing EVTOL) you see 20-25% packaging overhead.
- justoreply 4y ago11000lbs -> 5t
- rcarr 4y agoI wonder if this will lead to increased or decreased quality of life for truck drivers. The UK and EU are still aligned on truck driving rules for the time being. In the UK, trucks are limited to 60mph on the motorways which means there's a theoretical max limit of 540 miles a day on a standard day or 600 miles on an extended day. It's also mandated that you have to take at least 45 minutes rest every 4h 30 minutes which I imagine should be sufficient time to charge the vehicle to get the extra 40 - 100 mile range so I don't think EU drivers would really be impacted at all. It may have more of an effect in other countries which have higher speed limits however. I believe the laws in America are much looser so the effects there may be far greater. I believe US truck drivers can drive for up to 12 hours, so if these were widespread you would imagine US truck drivers may be getting more and longer breaks than if they were driving ICE. Summary of EU Driver Laws for anyone interested: https://www.gov.uk/drivers-hours/eu-rules https://www.gov.uk/drivers-hours/eu-rules
- deleted 4y ago[deleted]
- vardump 4y ago> be sufficient time to charge the vehicle to get the extra 40 - 100 mile range I think 45 minutes is enough to get closer to 300 miles of additional charge than 100.
- JoeAltmaier 4y agoCould a different technology, one perhaps with a higher weight per Wh but a higher Wh capacity per volume, make more sense in a semi-trailer-truck? Since on some routes they cruise for up to 11 hours, the weight could be less significant that a car doing city driving.
- ratata 4y agoWe need to taxes vehicles by weight. Vehicle weight is the biggest contributor to road surface wear. The damage cause by trucks accounts for 99% of road surface damage. [0]https://www.insidescience.org/news/how-much-damage-do-heavy-trucks-do-our-roads https://www.insidescience.org/news/how-much-damage-do-heavy-...
- mikestew 4y agoPrettttty sure that's the case in the U. S. Are they taxed enough? There's a strong argument to say that they're not. But here's just one URL indicating that there is a tax on heavy vehicles: https://www.irs.gov/newsroom/truckers-must-pay-heavy-highway-vehicle-use-tax-by-august-31 https://www.irs.gov/newsroom/truckers-must-pay-heavy-highway...