[Nick]

Chinese electric vehicle manufacturer BYD has recently unveiled it's new battery technology that aims to solve one of the biggest flaws with EVs, along with easing EV owners' charging anxiety.

BYD claims that the "Super-E" platform can add up to 290+ miles of charge in just a 5 minute session - somewhat similar to filling a petrol car up at the pump.

Read more about this exciting new development at this link.
I'd love to know your thoughts...

BYD unveils new battery technology to 'solve' one of the biggest flaws with EVs (source: ThisIsMoney.co.uk)

[Rolebama]

The only way I have heard of that sort of possibility would generate a heck of a lot of heat. If such a thing were possible, how would this heat be dissipated before causing serious damage to the battery, wiring or charger? Seems to me someone's living in cloud cuckooland.

I seriously look forward to the day when such a thing would be possible.

[olduser]

What do I think?

In round figures the 5 mins charge equates to about half a tank of fuel.
But it is progress.
I have not heard of a charging system, outside of China, that can charge at that rate.
The article mentions 1,000V at 1,000A that is one heck of a demand = to about 10,000 houses.
Switching and controlling that so no user can electrocute themselves or cause a major fire will need a well engineered, and maintained connection system.

There is mention of motor speeds of over 30,000 RPM, that's is going to need a very large reduction ratio, and a very highly engineered motor!

If by dual motors they mean two motors on one shaft, that is a known way of reducing the cost of the motor control electronics but it increases complexity.
High frequency, and high current with semiconductors usually means very high cost.

[Beelzebub]

Apart from the points raised already, what size would the charging cable have to be, to carry 1,000 Amps?

Will a normal human driver be able to lift it?

[Drivingforfun]

I imagine the regulations in China are much more liberal ... i.e. super fast charging has probably been do-able for ages, just in the West we have all these pesky health and safety laws. I guess Chinese inventors don't have to worry about minor stuff like huge heat generation and how to dissipate it safely 😆

Not having a go at a whole nation or trying to be racist, more just the govts, I think regulations and such don't really exist over there ... for better or worse ... similar to how they do a £4000 car or something in China but to make it pass UK road safety would bring it up to about £14,000

[Nick]

Originally Posted by Beelzebub

Apart from the points raised already, what size would the charging cable have to be, to carry 1,000 Amps?

Will a normal human driver be able to lift it?

My understanding is that the chargers and subsequently the vehicles, utilise two charging cables, so two charging ports on the car, which splits the voltage across the two.

[Beelzebub]

Originally Posted by Nick

My understanding is that the chargers and subsequently the vehicles, utilise two charging cables, so two charging ports on the car, which splits the voltage across the two.

Good idea, but they'd split the current, not the voltage.

[Nick]

Haha, shows how much I know! Splitting the current is the one!

This YouTube video breaks down some of the newly announced features and what they mean:
https://www.youtube.com/watch?v=7bn6CIMtgLY

[Beelzebub]

Originally Posted by Nick

Haha, shows how much I know! Splitting the current is the one!

This YouTube video breaks down some of the newly announced features and what they mean:
https://www.youtube.com/watch?v=7bn6CIMtgLY

Thanks Nick, really interesting video.

It will be interesting to see if they can make their "super-chargers" compatible with the UK grid. Maybe use their new battery technology - huge batteries in the "filling stations" topped up slowly from the mains?

[NMNeil]

Originally Posted by Beelzebub

Apart from the points raised already, what size would the charging cable have to be, to carry 1,000 Amps?

Will a normal human driver be able to lift it?

2/0 Welding cable is 10mm in diameter, not the whole cable, just the copper conductor and its rated for 325 amps and weighs 0.48 pounds per foot, so three of those cables together will easily handle 1000 amps for 5 minutes and so a 10' charging cable would weigh a total of 14 pounds, with insulation and the connector it should still be around 20 pounds total, so it's doable.

[NMNeil]

Originally Posted by olduser

There is mention of motor speeds of over 30,000 RPM, that's is going to need a very large reduction ratio, and a very highly engineered motor!

Electric motors that spin at 45,000 rpm are readily available, so the engineering challenges have already been overcome.
https://www.burgiengineers.com/produ...ectric-motors/

[Rolebama]

I use relatively small brushless motors for my rc planes, and fitting 9 x 6 props in itself reduces the max rpm. Free spin they run between 36/45,000 rpm. (As rated by manufacturer.) I haven't got the equipment to check loaded rpm. So 30,000rpm doesn't seem an excessive claim, assuming they are also brushless. If it turns out they're not, I can't envisage they having a particularly long life.

[olduser]

I wonder if someone in the area tried to charge his new Chinese car with his new charger?

https://www.bbc.co.uk/news/articles/c1jp1dg7g45o

[olduser]

Originally Posted by Drivingforfun

I imagine the regulations in China are much more liberal ... i.e. super fast charging has probably been do-able for ages, just in the West we have all these pesky health and safety laws. I guess Chinese inventors don't have to worry about minor stuff like huge heat generation and how to dissipate it safely 😆

Not having a go at a whole nation or trying to be racist, more just the govts, I think regulations and such don't really exist over there ... for better or worse ... similar to how they do a £4000 car or something in China but to make it pass UK road safety would bring it up to about £14,000

Something that Trump doesn't understand but China does is, if you are producing for the world market then you must comply with local rules, and regulations in that marketplace.

So I have no doubt that the design of the car, and charger, will have taken that into account.

[olduser]

Originally Posted by Beelzebub

Apart from the points raised already, what size would the charging cable have to be, to carry 1,000 Amps?

Will a normal human driver be able to lift it?

Think medium to large electric welder, and that is only one conductor, the charger would need two.

[olduser]

Originally Posted by NMNeil

Electric motors that spin at 45,000 rpm are readily available, so the engineering challenges have already been overcome.
https://www.burgiengineers.com/produ...ectric-motors/

There is no doubt it can be done (high speed motors) but they are very expensive.
We could have atomic clocks in cars but we don't because of cost.

I have used Tool Post grinders in the past to machine rubber, they ran around 30,000 RPM but the maintenance requirements were very high, and expensive.
We had one disintegrate, thank goodness the lathe was running on auto so no one was stood at it.
The manufacturer reported that a bearing had failed in the grinder, the rotor touched the stator, and that was the end.
The kinetic energy in the rotor had to go somewhere resulting in extensive damage to the surroundings.
A tool post grinder can be carried in one hand.

[Iyke]

@Nick sounds exciting but I think it’s overkill. Besides speed = money, i think 250/300 is fast enough. One of the great things about EVs is that you charge them when they’re not being used.

[olduser]

Originally Posted by Rolebama

I use relatively small brushless motors for my rc planes, and fitting 9 x 6 props in itself reduces the max rpm. Free spin they run between 36/45,000 rpm. (As rated by manufacturer.) I haven't got the equipment to check loaded rpm. So 30,000rpm doesn't seem an excessive claim, assuming they are also brushless. If it turns out they're not, I can't envisage they having a particularly long life.

Bad night couldn't sleep, thought more about gearing down from 30,000 RPM.

Assuming 100 MPH at 30,000 RPM, 24 inch wheels say 1400 RPM @ 100 MPH, Overall drive ratio = 21,4
Max practical gear ratio in one stage is about 4:1 that gives large first stage gear 7,500 RPM I'm not sure how to lubricate that but assume we can , next stage say 3:1 large second stage gear 2,500 RPM that would run in oil like a normal gearbox, leaving a final drive (diff) ratio of 1.8:1

I think this would have to be a dry gear box, (like a dry sump engine) oil pumped into the meshing gears, with the used oil draining down the sides of the gear box, to be pumped away avoiding oil collecting in the gear box, to be cooled and deaired then pumped in again.

It looks expensive to me!

[NMNeil]

@olduser Tesla have already worked out all the bugs including a variable speed oil pump.

[olduser]

Originally Posted by olduser

Bad night couldn't sleep, thought more about gearing down from 30,000 RPM.

Assuming 100 MPH at 30,000 RPM, 24 inch wheels say 1400 RPM @ 100 MPH, Overall drive ratio = 21,4
Max practical gear ratio in one stage is about 4:1 that gives large first stage gear 7,500 RPM I'm not sure how to lubricate that but assume we can , next stage say 3:1 large second stage gear 2,500 RPM that would run in oil like a normal gearbox, leaving a final drive (diff) ratio of 1.8:1

I think this would have to be a dry gear box, (like a dry sump engine) oil pumped into the meshing gears, with the used oil draining down the sides of the gear box, to be pumped away avoiding oil collecting in the gear box, to be cooled and deaired then pumped in again.

It looks expensive to me!

The motor torque is being multiplied by the reduction ratio. (21.4)
Advantage of higher RPM is less torque needed at the motor = less current (current is about proportional to torque) = greater mileage per charge or smaller battery.