Seems very open ended - it strikes me that political will would play as great a part as anything. Time is also a factor. I live near a major hub (an airport) and there are not many chargers in the public domain around here within miles. Depends on (cynically) "incentives" (?!?) offered to counsellors and the overall transport policy from C. Govt..

What about battery life of new super battery vs lithium-ion? How toxic are the byproducts and/or how easily recycled are they? Economic viability for lots of use cases depends on how many charge cycles the battery will last for, while toxicity and/or ability to recycle eventual waste will have a major effect on government enthusiasm or distaste.

(1) You forget electric buses, which are a huge thing in places where public transportation is a thing. (2) In many large European cities, a large part of public transportation has always been electric, using streetcars (= tramways), underground trains, and trolley buses. Here in Bucharest all the rage is now hybrid trolley buses which can also operate on battery, using the overhead power lines where available but being able to escape the wires and travel to places where no trolley bus had gone before. (3) In case I was not clear: current batteries are plenty good enough for urban buses.

Current batteries are perfectly fine for 'urban' use, they hold enough charge to last long enough to get you anywhere you'd need to in a town and they charge fast enough, only real problem with electric cars in towns right now is all to do with the support infrastructure, meaning not enough power on the grid to supply them all and keep supplying what it's already supplying if everyone converted right now, and better batteries would do f'all to help with that, so, how would it change things you ask? It wouldn't change anything meaningful at all for "urban" transport ..

.. you should have asked about non-urban transport, there it 'might' make 'some' plausible difference to how and who uses them for what as the current ones often don't last long enough between charging for many peoples needs, particularly with the (so surprising, not) lack of charging points scattered randomly around the countryside so you can top up mid journey.

I’m voting to close this question because it is an off-topic high concept question. HCQs posit a seemingly simple change (10X battery capability) and then ask for enormous, ill-defined consequences (biggest change to transportation modes). They're notoriously open-ended, broad, and opinion-based, all of which is prohibited in the help center. Worse here, it's asking for "biggest," that's only ever a story-based request.

@AlexP To continue on his point, this works very well for busses as they can be recharged (while idling at an end station). Or they swapped out at some point during the day for another, getting recharged/cleaned/repaired. With long distance trains it would mean that long stretches of railway can be without lines overhead, kinda like the hybrid bus. The problem I see is with the recharge time. If an transportation vehicle can't be used during the recharge time (which stay the same), they become a liability, sitting still with cargo for many times the duration a fuel refill would take.

@vinzzz001: Urban buses have a natural rest period at night. Assuming that they run 16 hours per day and their average speed is about 30 km/h (which is very optimistic) this comes to 480 km per day; that's easily achievable with current battery technology. And rail, even light rail, is so expensive that the additional cost of installing the overhead wires or third rails is a minor part of the effort.

How sensitive are the batteries to temperature? This is currently a significant factor affecting adoption of electric vehicles in places with serious winters. (Or, alternatively, could affect use in places that get too hot.)

@Jedediah: Battery electric vehicles have thermal management for their batteries, heating them up when it's too cold outside. The batteries are not kept negligently at ambient temperature. For example, in 2022 more than 80% of the vehicles sold in Norway were electric; Norway is one of those places with serious winters.

@AlexP I just know I was seeing a bunch of stories about electric cars and a cold Chicago winter... You're presumably thinking more about mass transit and large vehicles, where it might not be such an extraordinary waste of energy to keep individual batteries temperature-contolled.

@JBH I spent a lot of work trying to keep this narrow in scope and I'm asking about the biggest change to urban transportation in particular. How is this high concept?

@Asking for the "biggest" change was an attempt to make answers semi-objectively judgeable

I feel there would be an immediate and clear effect of that change, so also a kind of objective answer (as far as an answer on this stack can be). 10x bigger batteries for everything else (price, weight etc) the same? You get cheap electric cars with batteries only 1/10 of the current size. Cities will be even more clogged than today but with better air quality and less noise. I don't really get why this got closed.

@Zags It's high concept because it's asking for a breathtakingly wide scope. All transportation modes? All cities in all developed countries? There are thousands of variables and how electrification will impact society has already been the subject of an entire book. You're not asking for help solving a specific problem. Then there's the issue of "biggest." What defines the "biggest" impact? ... (Continued)

... Economics? Pollution? Noise levels? The discomfort of little old ladies living next to freeways? There are no questions which as for the biggest, best, worst, largest, smallest, (or any other superlative) that aren't 100% story-based because only the conditions of the story can define the metrics for the condition. A simple rule to follow is this: if you can't clearly and specifically explain how you'll judge a best answer, you're not asking a well-scoped question. One more thing ... (Continued)

... The fundamental problem that nearly everyone dealing with electric vehicles fails to understand is that population growth continues. Reduction of pollution and noise are, very generally speaking, the only improvements that will be seen because everybody will continue to need transportation for a wide variety of reasons and the population's continued increase will always put pressure on the generation of energy and pollution. Electric cars aren't magic, they're just the next step in maintaining the status quo.

@JBH I can pretty clearly explain how I'd judge an answer (and have added this to the question). What new transportation mode is used by the largest percentage of the population on a regular basis? Doesn't seem story-based to me.

@Zags Where? London? New York? Salt Lake City? Tuscon? Cairo? Honolulu? They all depend on different transportation technologies. Some of which already use electrified vehicles by the majority. I can list a lot of variables you're simply ignoring, all of which prohibit the selection of a best answer. And you're ignoring the truth: today I drive a combustion car. Tomorrow I drive an electric car with one of your new batteries. So what? And do we consider only residents, or do we consider freight and/or agriculture? I can go on for a long time.