How could a battery charge faster?

[phidauex]

I suspect that any improvements in charge speed are going to be directed to DC fast charging stations and specialty applications like fleet vehicles.

Unfortunately at a home you aren't going to get much more than 40-50A. The most typical electrical service in a US home is 200A (38kW usable) though 150A and 100A are quite common. For 150A and 200A services you can usually add one, maybe two 60A branch circuits without having to make other major changes. For 100A services you might be able to squeeze in a 40A branch circuit. But regardless of what the battery can charge at you just won't be able to bring enough power into the service to support even 50kW charging.

But I don't think that matters much because home charging will always be of the "overnight slow charge" type - people won't need to charge super fast at home.

For fast chargers, it will be interesting to see where the voltage ranges go. Stationary applications are up to 1500V in many applications now, with a lot of systems running at 1200V. The higher you go the more power you can push through the same cable, but you also have to increase the insulation on all the components, and the consequences of a failure goes up. The NEC restricts you to 1000V on occupied structures, for instance. I suspect that the 800V standard will prevail for quite a long time, and that voltage along with the current handling capabilities of a flexible handheld cable will set the maximum charge rate available, regardless of the battery technology.

But even a battery that can't charge faster, but still maintains the full charge power through the whole curve would be a big improvement - at 150kW the ER MachE would go from 10% to 80% in only 25 minutes if the battery supported the full charge rate.

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[timbop]

Keep in mind Ford is a founding member for these discussions and is probably leading all the nitty gritty.

Completely correct. Heat rise in a wire increases by the square of the current, hence the high voltage transmission lines. Here's a great practical example showing thin wire powering a hair dryer at high voltage, but immediately burning up at low voltage...

Ron's actually an engineer at Ford, but I'm sure he appreciates the confirmation that he knows what he's talking about

 

[AZBill]

The current CCS standard supports up to 1000V DC and up to 500A DC. That would equate to 500KW, but the stations are currently limited to 350KW. The input to the EA stations is 480V AC.

There are two classes of EVs today, the 400V-450V systems and then the 800V-900V systems. Mach E is a 400V system. For 400V systems the maximum charge rate is 200KW, i.e. 400V X 500A. The 800V systems can provide 350KW at 437.5A. Porsche Taycan is an 800V system and it can charge at 270KW, that is currently the highest production vehicle out there. The new Hummer EV will charge at 350KW, and many of those are now out testing.

None of the vehicles can charge at those high rates all the way to 100%, that is what would destroy the battery, so there has to be some taper as it gets close to full charge. It is usually not good to charge beyond 2C, where C is the capacity of the battery. For example, a battery with 100KWH capacity would charge at 1C for 100KW or at 2C for 200KW. The Hummer battery is rated at 200KWH, so charging at 350KW is 1.75C. If you tried to charge a 100KWH battery at 350KW, it would likely damage it at 3.5C.

So there are three factors that limit the charging capability of the batteries:

1) Battery capacity
2) Battery voltage
3) Available charging current at that voltage

 

[TheVirtualTim]

Ask a physicist and they'll tell you if the thing is possible ... does it violate laws of physics?

Ask an engineer ... and they'll answer based on whether anybody can figure out how to actually BUILD the thing. An entirely different problem.

For example... reacting anti-matter is 100% efficient (all matter is converted into energy with no waste). The mass of a paper clip (about 1 gram) would translate into about 25 million kW of power. So that's pretty good. If you don't mind the side effects of things like gamma radiation. ? This is no problem for a physicist ... but quite another problem for an engineer.

Before you run out to place your order on a matter/anti-matter powered car ... keep in mind anti-matter is expensive. It can be produced in particle accelerators like CERN or Fermilab. But in such tiny quanties that the cost is currently around $4 trillion per gram. So I'm thinking this tech probably not in our future. But it fun to speculate.

 

[Carsinmyblood]

I wonder in what year we'll look back and think how crazy it was to store electricity by messing with chemicals in a box.

 

[barryvo]

I'm new here and have MME on order projected to arrive around Christmas. I'm okay with the current charging curve but would be delighted if Ford could improve it a bit with a software update. Especially the DC rate from 20 to 80 percent.

I'm not an engineer but think Ford is playing it super conservative so they don't have to potentially deal with a major recall or battery warranty issues. There are a lot of so called gurus on YouTube saying the same thing.

Time will tell if they can improve the road trip charging experience a bit.

We plan on using the mostly in town. Especially with DC charging being so expensive. I ran the numbers and it appears to be the same or more than gas in most situations. Charging at home is a fourth of the cost.

 

[jrstinkfish]

I would love for the Mach-E to have an option to not take 2+ hours to charge to 100% at a DC fast charging station. Watching the ID4 do 0-100% in an hour makes me insanely jealous (of the charging, not the car itself ...). If nothing else, have a "Road Trip" button on the screen that allows you to alter the charging curve for the times when you don't have over 2 hours to spare so that folks aren't just automatically straining the battery (I assume that is why it slows down so much at 80%).

 

[murphy62]

I would love for the Mach-E to have an option to not take 2+ hours to charge to 100% at a DC fast charging station. Watching the ID4 do 0-100% in an hour makes me insanely jealous (of the charging, not the car itself ...). If nothing else, have a "Road Trip" button on the screen that allows you to alter the charging curve for the times when you don't have over 2 hours to spare so that folks aren't just automatically straining the battery (I assume that is why it slows down so much at 80%).

Compare battery charging with the following.
Hold a glass beaker in your bare left hand.
Pour a very strong acid into the beaker and fill it to the top.
You will slow down as the level nears the top because the penalty for overflowing is severe.

An Li-Ion battery can self destruct if it is overcharged.

That said I doubt that indicated 100% is the actual 100%. It is belived that a 100% indication in my 2013 Ford Fusion Energi battery is actually 95%.

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