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Comment by tristanj | Hacker News Reader

I did not expect Nio's 5-minute battery swap technology to become obsolete this soon.

If anything, Nio battery swap stations would allow car users to swap to newer types of battery as they become available. I say this knowing Nio is one of CATL's most important partners[1].

[1] https://eletric-vehicles.com/catl/catl-calls-nio-an-irreplac...

In a well designed urban environment where cars have space for 2-3 modular batteries with swapping capabilities, I see no reason why taxis etc. need to carry battery payload > 150 km of range needed for local use, which would mean better fuel efficiency as well. Battery swapping done right is integral to this

Sorry, but I giggled at this. A well designed urban environment would have no cars.

Frankly - I agree with this take.

If anything - my opinion at this point is that cars were a mistake in vehicle sizing caused by internal combustion engines.

For the vast, vast majority of ubran transit, something akin to a bike in size seems to make more sense.

We see this already in urban regions in India/Asia where scooters are the predominate transportation method, and I think even traditional scooters are heavy enough to be problematic.

But a class 2 ebike (so throttle with no need to pedal) can weigh as little as 40lbs (20kg), and go 30 miles at 20mph.

It's insane that we're not designing urban transit for bikes at this point. Much better density, much safer, much easier to store and park, much cheaper to operate and license.

Cars,those urban monstrosities the vehicles that weigh over 25 times their payload and take up 20 times the space on the roads.

Should I adjust the figures for American sizes?

Should I also add that they are engineered to travel at speeds over 120 mph and usually ply the trade environments where 30 mph is a dangerous speed?

Amazing machines. Can't wait till I can buy something a bit bigger that can also travel to other planets

In an ideal world, yes. But the only way to move forward is somehow modifying the existing world for better, step by step.

but you/stuff still needs to go from a to b. taxis (or individual self driving pods) should however be the future of public transport.

They simply lack the required space density.

That'd be an interesting situation. They'd probably replace their fleet of batteries gradually, so with each swap sometimes you'd get upgraded, sometimes downgraded. Your range and home charging curves would change with the batteries, and Nio would have to update the battery management software when it puts in a different battery type.

But over time, you'd get upgraded on average without having to pay for a new battery, as long as Nio kept updating to keep its batteries competitive.

This is in fact the main argument to me why swaps would never work at all, economically: the "state" of the battery is a significant part of the value of the car. Being swapped to a worse one makes you several thousand dollars worse off.

It only works in a leasing scenario, and everyone hates those.

I think you'd need a contract where you buy (or lease) the car without a battery and lease/rent the battery separately. With some guaranteed offer for a battery with minimum spec X at maximum price Y when you exit the battery program. Preferably, not a mandatory offer, because one hopes specs go up and prices go down over time.

Then have you pay something per month for having a battery (maybe depends on the specific battery installed), something per kWh for charge used, plus a rebate per kWh for charge added. Or roll it into usage tiers, whatever.

There's lots of people that love leasing cars. I don't understand it, but it makes a lot of people happy?

I used to own a truck whose fair market value would double, temporarily, whenever I filled the tank.

How's that any different than putting new tires on a shitbox?

Nio already has a service to swap to higher capacity battery if you want to go on a long road trip etc. It prices its cars according to battery capacity so even people that chose lower capacity car on purchase still have the option to swap to a higher capacity battery. Though I think the main use for battery swap technology will be for commercial trucking and if I recall correctly Chinese government and OEM are working on standardisation for that so all those truck batteries are swappable no matter which company builds the battery.

5 minute swap is not needed for this.

Well, if it degrades to 90% after three years, and let’s extrapolate to 81% after another two to three years, then a battery swap in 5 minutes might be reasonable to do instead of charging once every three to five years or so. I guess it depends on the quality and retained capacity on the batteries being swapped in.

The vast majority of charging is done at home, though. Five-minute-charging/swapping is basically a gimmick to show off to your friends, and only really sees (questionable) use during that once-a-year road trip.

The main value in these technologies is to shut up the "But sometimes I want to drive for 20 hours without being forced to take even a single 30-minute break!" pseudo-argument as to why an EV is "impossible" for their lifestyle. Same with the Lucid Air and its 1000km range: basically zero people truly need it, but it needs to exists in order to drag the last few holdouts into the future.

When my road trip is in negative temperatures, I appreciate not having to be in the cold for too long. I think the bigger adoption issue is thoughts of scaling the charging stations. If there’s a line of cars at a liquid fuel pump, one can still get fuel in twenty or thirty minutes. If there’s a line of four cars at every charger and every car takes 15 minutes to charge on average, that’s an hour before you can start.

> Well, if it degrades to 90% after three years, and let’s extrapolate to 81% after another two to three years,

That sounds like a phone battery, not an EV battery. Modern EVs should last 15-20 years before seeing significant degredation.

That was assuming, based on their recharge count, daily 10% to 98% rapid charging. You’d only see that in a vehicle of this range if it’s being used as like a courier vehicle or moving billboard. Pretty much the actual worst cases.

> Well, if it degrades to 90% after three years, and let’s extrapolate to 81% after another two to three years, then a battery swap in 5 minutes might be reasonable

eh? are you saying that something that is done once every 5 years has to be done inside 5 minutes? I strongly disagree.

> charging once every three to five years or so

Um, that's not how charging works at all.

That’s not how sentences or quotations work at all.

We should always take marketing number with a huge grain of salt, so the 10 to 98% in 7 minutes remain to be seen. Also, there is the question of if it lowers the battery lifespan faster than charging at lower power. It is does, there might still be a point in battery swap, especially for public transport systems (for bus). A public transit operator might want to have more battery than vehicle, so that they can rotate the battery regularly and charge them at lower power, to diminish and distribute the wear on battery. But that's obviously a big if and a more niche usage.

> there might still be a point in battery swap, especially for public transport systems

There isn't. Buses aren't really size- or weight-constricted and don't drive at highway speeds, so building one with enough battery capacity to last most of the day isn't a big deal. Plenty of cities have already transitioned to a 100% electric bus fleet, after all.

A big thing to remember is that people don't travel at the same volume at every moment of the day, so you don't need to run buses at the same frequency the entire day either. You can run buses at 10-minute intervals during commute hours, 15-minute intervals in the middle of the day, and 30-minute intervals in the early mornings and late evenings. This means that there is plenty of time between the morning rush and the evening rush for some buses to go off-duty and charge for a few hour. They are going to sit idle anyways, so why not make use of it?

There are many cases where the EV busses have been abandoned. Busses typically do not do their route and stop, so getting a significant amount of charging for any busses requires extra busses that can be rotated on/off duty. If you design the system to depend on that charging then you need extra busses and you're effectively stuck with a sparse schedule. That is not a constraint to consider with petrol-powered busses. They can run nonstop as much as needed.

There is another thing cities should consider in all this: EV busses are totally unsuitable in emergencies. They cannot be charged fast enough, especially in extreme weather. You should consider this before buying an EV as well. At least, have a plan to arrange alternate transport with a reliable petrol vehicle.

> There are many cases where the EV busses have been abandoned

Source?

> Busses typically do not do their route and stop, so getting a significant amount of charging for any busses requires extra busses that can be rotated on/off duty.

Yes. But like I said: this was already the case with diesel buses. Nothing changes here. The duty rotation is demand-driven, not supply-driven.

> EV busses are totally unsuitable in emergencies.

Emergencies are the exception, and there are very few cases where regular city buses (of any kind) are going to be the backbone of a last-minute evacuation plan. And even in that case: usually you only need to drive a dozen miles / kilometers to get out of immediate danger - which should be perfectly doable.

> You should consider this before buying an EV as well.

I completely agree. Leaving a few dozen miles / kilometers of range in the battery not only is a sensible preparation for any kind of (natural or personal) emergency, but it is also better from a charging speed and battery longevity perspective.

the life span stat with the current battery tech is mostly useless for a normal car. 300 mile range most people will need to top up 2 times a week 100 times a year 1000 times in 10 years. The battery degradation is not that bad in the first place.

> most people will need to top up 2 times a week 100 times a year 1000 times in 10 years.

When it comes to as-fast-as-possible charging, I think you can divide that number by at least 10. Slow charging while parked overnight or during the day should still be the most common case by far for most users. Very fast charging is important for road trips, but it is not the usual case.

First, with range decreasing, number of charge cycles per mile, and therefore rate of wear, will increase.

Second, average age of car on the road is above 10 years in most countries; and those that drive old cars definitely do not have €26,500* spare to swap their EV's battery for a new one.

*That's what Audi charges here for e-tron 50 battery replacement, which are already starting to fail for many owners

> First, with range decreasing, number of charge cycles per mile, and therefore rate of wear, will increase.

By 10% over 10 years, assuming the worst case of nothing but ultra-fast charging. This seems minor.

Old cheaper cars could be 10% less convenient to use for very long trips. This should not shock anyone.

Rather than an expensive battery swap, sell it on at a lower price to someone who doesn't need 100% range.

That's a theoretical / marketing number. In real life I am yet to see meet an EV owner who reports >80% of range after 5 years / 100 000 km of mostly-at-home charging. I see those on internet forums, but on internet forums, anyone can write anything, so I do not take those reports too seriously.

From my personal family anecdotes: my mothers' 4 year old Hyundai Ioniq 5 had complete battery failure. Thankfully under warranty. And my fathers' 5 year old Audi e-tron 50 already has <80% range remaining, with very rare fast charging.

Western car manufactures scamming their customer should not be what you look at for costs. Batteries pack costs have gone from $130-150/kwh in 2023 $80-90/kwh in 2026. Price for a pack will likely be under $50/kwh in another 3-4 years. Ie battery packs are becoming competitive with engines already and will be cheaper by 30-40% ie replacing a battery will be cheaper than replacing an engine/

No car manufacturer actually sells battery packs for $80-90/kWh or anywhere near that. That's what it costs THEM, not service customers.

> Also, there is the question of if it lowers the battery lifespan faster than charging at lower power.

This kind of fast-as-possible charging rather than overnight or "while parked at the mall for hours" slow charging should be the exception rather than the rule, i.e. it is useful when road-tripping long-distance, but is not not the daily case. Battery lifespan should not be based on assuming that it's the only thing that you ever do.

Swapping does help reduce the high peak power demands that fast charging has. There's limited places where you can get the infrastructure to install a bank of chargers capable of this kind of speed (though, one potential approach is having a local block of batteries near the charger, but you are then paying the efficiency cost of another battery round-trip, and the cost of the batteries which will get a lot of wear and tear themselves)

The charging station's batteries don't have to use the same chemistry though, as they aren't space- and weight-constrained like EV batteries are. You can optimize for durability and cost instead.

Having station-based storage also allows the station to participate on the energy market and purchase only when electricity is cheap. It could even do double duty by selling back electricity from storage during periods of high grid demand! Heck, pair it with a local grid storage battery which is going to be built anyways and you basically get it for free.

Station batteries are an additional toxic inextinguishable fire hazard and expense to consider. I wonder what is the efficiency loss in charging one battery to turn around and charge another too. But you are generally right: stationary batteries do not need to be lightweight like the ones in cars.

But if you need batteries that gives you the opportunity to install solar and reduce your costs more than the efficiency hit.

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