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Apparently there's an important patent on lithium iron phosphate (LFP) batteries that expires next month (on April 27th). I'm hoping that changes the economics

• speedgoose 5y ago
  Is safety a criteria for school bus in USA? I thought it was only cost since the design is from the last century and many bus don’t even have seatbelts.
  • xxpor 5y ago
    Seat belts have been required in some states for decades at this point. We had them on buses when I was in elementary school 20 years ago, in NJ. Now... getting kids to actually use them is a different matter.
    • horsawlarway 5y ago
      In many of the most common situations - they just don't matter that much on a school bus. The bus is generally the largest vehicle on the road, and an impact from a car (or even pickup truck/suv) is unlikely to significantly move the bus. Plus - the sit very high, and impacts tend to drive the other vehicle down - rather than moving the body of the bus. The only situation they really are useful is when the bus rolls, and for buses that aren't driving highway speeds (which is most of them), they almost never roll (the only exception is essentially driver error - where the bus leaves the road on slope)
  • jws 5y ago
    The NHTSA recognizes that large busses are not cars and use a different solution. Large school buses are heavier and distribute crash forces differently than passenger cars and light trucks do. Because of these differences, bus passengers experience much less crash force than those in passenger cars, light trucks, and vans. NHTSA decided the best way to provide crash protection to passengers of large school buses is through a concept called “compartmentalization.” This requires that the interior of large buses protect children without them needing to buckle up. Through compartmentalization, children are protected from crashes by strong, closely-spaced seats that have energy-absorbing seat backs. Statistics bear this out, taking a school bus to school is about 70 times more likely to deliver a student safely. In this context, 70 is huge.
    • speedgoose 5y ago
      It’s a nice way to say that kids can slam the seats.
      • daemoens 5y ago
        They'll slam into the seats and still be safer.
        • freeflight 5y ago
          YouTube has plenty of videos showing the insides of school buses during crashes, anything that ain't a frontal crash has kids sliding and flying all over the place. They slide sideways out of the seats trough any serious horizontal forces, in the case of a rollover their heads will violently hit the roof as they literally take off from the seats [0], and then fall on the people on the ground side. [0] https://youtu.be/OvNjVQkye8Y https://youtu.be/OvNjVQkye8Y
          • MathCodeLove 5y ago
            YouTube also has plenty of videos of plane crashes, that doesn't mean that passenger aircraft are inherently unsafe, but that there are always risks associated with transportation and given extraordinary enough circumstances those risks will be revealed.
            • freeflight 5y ago
              The point here is not "school buses are inherently unsafe", the point is that they seem to lack a basic safety feature that's otherwise common, even in passenger aircraft, that of seatbelts.
      • deleted 5y ago
        [deleted]
      • mywittyname 5y ago
        And airbags is a nice way of saying a little bomb is going to blow up in your face if you crash.
  • kube-system 5y ago
    School busses have a ton of safety features -- just with a different strategy than is applied to cars. Part of the reason many don't have seat belts is because they are also designed to have safety features that work without seatbelts. The passengers are rowdy kids who might not always wear their seatbelts, so while adding them might increase protection in some cases, a safety design that primarily relies on seatbelts might not actually be a great idea. US school busses are heavy and sit very high. Busses can be hit by cars with little force imparted to the occupants. The most dangerous thing about school busses is the risk it poses to the other drivers that hit it: https://www.chron.com/news/houston-texas/houston/article/Crash-with-school-bus-kills-1-no-students-hurt-4111207.php#photo-3881715 https://www.chron.com/news/houston-texas/houston/article/Cra...
  • missedthecue 5y ago
    There have been a ton of DOT and NHTSA studies that have shown that seatbelts don't keep children that much safer during accidents that involve school busses, because the children are high off the ground, busses don't move at very high speeds, 48 children wearing seatbelts makes a firefighters rescue job 100x harder, etc...
  • bpodgursky 5y ago
    IIRC the conclusion was that requiring seat belts slows down the loading / unloading process and decreases ridership enough that more kids will actually get hurt when their parents drive them to school instead (since cars are far more dangerous to riders than giant heavy slow-moving busses).
  • elihu 5y ago
    When it comes to batteries, I can't imagine safety not being a major design consideration. EV fires are maybe exaggerated a bit in the media because of the novelty whereas ICE vehicle fires aren't as newsworthy, but they're still a thing that can happen and could potentially be very destructive and hazardous especially on something with a huge battery pack like a bus. Using a kind of battery that tends not to burst into flames if ill-treated seems like a good idea.
• sremani 5y ago
  I do not know if we are in a commodity super-cycle but Li price is brrrrrrr. https://www.dailymetalprice.com/metalpricecharts.php?c=li&u=kg&d=240 https://www.dailymetalprice.com/metalpricecharts.php?c=li&u=... The days of falling battery prices in dollar terms are over.
  • pg_bot 5y ago
    I think you are underestimating the ingenuity of humans. Shortages can lead to new, more efficient ways of doing things. High prices are going to encourage more lithium production, or research into perfect substitutes. It's highly unlikely that in a decade battery prices will be higher than they are today.
  • coryrc 5y ago
    Lithium is a tiny fraction of battery cost.
    • sremani 5y ago
      Materials are 60% cost of Li battery and across the board material costs are increasing. So, I stick to my assessment barring new evidence (which was not provided by your post), that Li battery prices falling in dollar terms is done. Reference: https://qnovo.com/82-the-cost-components-of-a-battery/ https://qnovo.com/82-the-cost-components-of-a-battery/
      • thescriptkiddie 5y ago
        The only component of the battery which contains Lithium is the cathode, which according to the article you linked is a little less than 1/3 of the material cost, or around 20% of the total cost. The battery chemistry which contains the most Lithium is Lithium Cobalt Oxide, which by weight is approximately 7% Lithium and 60% Cobalt. Even though Lithium is vastly more expensive than Cobalt, Cobalt still accounts for the majority of the cathode material cost. So it seems like Lithium accounts for at most 10% of the cost of the battery.
      • elihu 5y ago
• xxpor 5y ago
  Yes, that's a great point. Even if you ignore the usual idle time between the morning and afternoon runs, I have to imagine a range of 150-200 miles would cover ~95% of use cases. The bus problem therefore should be much easier than the long haul truck problem. Plus, there's no trailer so you could run the battery pack the entire length of the bus.
  • erosenbe0 5y ago
    One problem is that 'diesel outages' on school nights are extremely rare or nonexistent. Maybe deliveries are late or pumps break but it seems like a solved problem. Electric trains are also a solved problem and are hardened from many power outages too. Whereas some work needs to be done to harden the infrastructure at the school district level to avoid electric bus outages.
    • elihu 5y ago
      If there's a major power outage, the school probably won't be in session either. Though getting the students home might be a problem if power goes out in the middle of a school day and the buses haven't charged enough to get the students home. (If they have enough reserve capacity it's probably not an issue.)
      • xxpor 5y ago
        Worst case, you could have some diesel generators at the bus depot.
  • Gwypaas 5y ago
    They work really well for city buses also, although they need some charging at the ends. Still have a sweet spot in regards to range though even though the latest generation allows for high capacity buses. They needed to rework a bunch of lines to fit in the envelope. https://www.electricitygoteborg.se/en/news/improved-urban-environment-one-year-after-launch-145-electric-buses https://www.electricitygoteborg.se/en/news/improved-urban-en... Also helps that Volvo is headquartered in Goteborg, so always eager to try new things. The first "prototype" style BEV bus line opened early 2015.
• mardifoufs 5y ago
  LiFePo batteries are already getting produced in huge numbers in China and are very cheap even here in the west. Could the Chinese LiFePo products legally be imported if they were using patented tech? Or is it a specific variation of LiFePo that is patented, and could make the batteries better? Because at 150-250$/kWh retail price it's going to be extremely hard for local manufacturers to compete in the market against established Chinese manufacturers that can already make state of the art, high quality batteries at insane volumes.
  • elihu 5y ago
    I'm not 100% sure what the situation is, but I think the issue is that if some car manufacturer tried to import a large quantity of LFP cells from China they might be sued if they don't pay the patent licensing fees. Thus the price of LFP cells in China isn't the same as the price of LFP cells anywhere else purchased through legitimate channels. (I'm not sure if the cheap-ish cells you can get on AliExpress are paying those royalties or if they're kind of flying under the radar.) I'm hoping to see sub-$100 per kwh LFP cells sometime soon in the U.S. through some channel that ordinary people can order from. It would be a huge boon for EV conversion if the batteries weren't hugely expensive. I think that's probably attainable. LFP batteries aren't fundamentally expensive, you just need to have good automation, cheap energy, and economies of scale. The input materials are relatively cheap. China's main advantage besides the patent thing is that they've been quietly building their battery manufacturing capabilities and supply chains for a couple decades, and it's hard to compete with that.
• dont__panic 5y ago
  I'm curious how they perform in cold conditions. Where I grew up, a solid 50% of the school year was at or below freezing regularly. We really worked those bus heaters -- you know the type, under a few seats scattered around the bus. Curiously, it doesn't seem that buses use heat from the engine, like most ICE vehicles, for heat. Instead, I'm pretty sure they were just using power from the motor for electric heating elements with fans. Given that an electric bus could easily fit an enormous battery slab under the seating, I wonder if electric buses could be even better than ICE buses in cold conditions -- barring the obvious issues with battery efficiency in cold.
  • Mountain_Skies 5y ago
    Wonder if radiant floor heating would be a good solution. Adding a warm air blower near the front to counteract cold air intrusion from opening and closing the door could help keep the interior of the bus a nice constant temperature.
    • mjevans 5y ago
      Single pane (if thick) windows, very loosely sealing; in recent years possibly open for fresh air even in cold months. I grew up in a semi-temperate region that only had at most maybe a month of really cold temperatures each year. Those under-seat heaters were still very nice to be near and also helped to melt the snow and slush into just ice on the floor. You should assume, from a heating and ventilation perspective, that the inside of a school bus is a mobile open air tent, but simultaneously also on the verge of being an enclosed space packed to the gills with people.
  • elihu 5y ago
    LFP batteries don't handle below-freezing temperatures very well, but that could be mitigated by using insulation and water cooling/heating depending on the time of year. Also maybe hooking them up to a pre-heater system that gets the batteries up to temperature before their route begins. (Sort of like those oil pan heaters they use in really cold climates.) Cabin heating could be done with a heat pump for more efficiency, I suppose. Heating could consume quite a bit of power, but I suppose compared to the energy required to move a school bus around it's probably fairly minor.