Charge LEAF Battery in 5min!

[padamson1]

Noticed this over on the Nissan LEAF blog site. If this is scalable and doesn't damage the battery, it will be a game changer

http://nissan-leaf.net/2011/06/21/engineers-develop-system-that-charge-evs-in-5-minutes/

If you follow the source links it appears that the system uses super-capacitors, I'm not sure why that makes any difference...

 

[davewill]

...If you follow the source links it appears that the system uses super-capacitors, I'm not sure why that makes any difference...

It allows the energy for the 5 minute charge to be stored up in the charger over time. Trying to pull that much energy off a local transformer in 5 minutes would be a huge strain.

 

[Stewy13]

I really like the idea of this, almost makes it as convenient as the swappable battery idea. However I truly wonder how practical this idea is, and if it is then; how long must we wait?

The problem with articles like these is that they clearly could be game changers for EVs, rarely do you read about it again. Clearly I hope we hear more from both the developer and perhaps EV makers concerning much faster charging and how to accomplish it.

 

[Ready2plugin]

What if they hook this bad boy up to a Bloom Box?....then it would be off the grid as well.
http://www.bloomenergy.com/

 

[gmuzhik]

I did a quick calculation to charge a Leaf 24kWh battery in 5 minutes. It would require 288kW if my calculations are correct. This would be 576 Volts at 500 Amps! Yikes. I can't imagine what a 500 Amp cable would look like. On Wikipedia, they say the Leaf QC port is capable of 62.5kW or a little over one fifth of the power. I would like to know how much current this charger supplies and over what kind of connector!

 

[mxp]

It's not clear which charging port would you hook up to get the benefit of that 5 min charge. Is that via the DC quick charger port?

I can't imagine using the existing J1772 since I was under the impression that the charging time/kWh limit was due to the 3.3kW charger installed inside our current LEAFs.

Anyways, it's quite ambiguous.

 

[LTLFTcomposite]

I did a quick calculation to charge a Leaf 24kWh battery in 5 minutes. It would require 288kW if my calculations are correct. This would be 576 Volts at 500 Amps! Yikes. I can't imagine what a 500 Amp cable would look like. On Wikipedia, they say the Leaf QC port is capable of 62.5kW or a little over one fifth of the power. I would like to know how much current this charger supplies and over what kind of connector!

Kind of puts an upper bound on the viability of EV's for anything more than around town use. Not that that's a problem, just need to face facts.

 

[LEAFfan]

I really like the idea of this, almost makes it as convenient as the swappable battery idea. However I truly wonder how practical this idea is, and if it is then; how long must we wait?

The article said they will be installed in homes and businesses in 2012 in Japan and later in the U.S.

 

[LEAFfan]

It's not clear which charging port would you hook up to get the benefit of that 5 min charge. Is that via the DC quick charger port?

Since it's a 'fast charger', it looks like to me they are using the DC fast charge port on the LEAF. It charges to 90% instead of the now fast chargers that only charge to 80% in 20-30min.

 

[ElectricVehicle]

Kind of puts an upper bound on the viability of EV's for anything more than around town use. Not that that's a problem, just need to face facts.

The Tesla Model S with the 300 mile range option is good for a lot more than "around town", or maybe your town is 300 miles across? Future vehicles with 150+ mile range and the ability to charge at 50 miles / hour of charging (12 kW, 240V 80A circuit) which is still within J1772 spec, will cover more of your trips. With Quick Charge thrown in and a larger pack, think about charging up 160 miles of range in under an hour. Things are happening. This is just the beginning!

 

[padamson1]

gmuzhik wrote:

I did a quick calculation to charge a Leaf 24kWh battery in 5 minutes. It would require 288kW if my calculations are correct. This would be 576 Volts at 500 Amps! Yikes.

1. To get that much energy onto the car there must have been some sort of customization, you can't just stick with 440V because the copper cable resistance is essentially fixed (but I could just be stupid since I didn't even understand the value of super capacitors).
2. I'm thinking they mean 80% (20kWh) for a 'charge'.

To get that much kWh in 5min you need 240kW instantaneous power. Since R is fixed around 5 ohms, I'd use voltage as the variable:

P=V^2/R => 240kW * 5=V^2 therefore V = 1095volts at 220amps.

Still needs a pretty damn thick cable but not unheard of. The real point is I'd doubt our government regulators want that much energy flowing around in somebody's garage, so I don't think this is going to be a home charging option any time soon.

 

[UkrainianKozak]

gmuzhik wrote:

I did a quick calculation to charge a Leaf 24kWh battery in 5 minutes. It would require 288kW if my calculations are correct. This would be 576 Volts at 500 Amps! Yikes.

1. To get that much energy onto the car there must have been some sort of customization, you can't just stick with 440V because the copper cable resistance is essentially fixed (but I could just be stupid since I didn't even understand the value of super capacitors).
2. I'm thinking they mean 80% (20kWh) for a 'charge'.

To get that much kWh in 5min you need 240kW instantaneous power. Since R is fixed around 5 ohms, I'd use voltage as the variable:

P=V^2/R => 240kW * 5=V^2 therefore V = 1095volts at 220amps.

Still needs a pretty damn thick cable but not unheard of. The real point is I'd doubt our government regulators want that much energy flowing around in somebody's garage, so I don't think this is going to be a home charging option any time soon.

The only way I can see that feasible with stock hardware is if they put supercaps in the car, charge supercaps using their high voltage/amperage charger and then used those supercaps to charge Leaf whenever Leaf stops, but that would be a waste... If you have that much supercaps, you might as well throw out the main battery...

 

[evnow]

I did a quick calculation to charge a Leaf 24kWh battery in 5 minutes. It would require 288kW if my calculations are correct. This would be 576 Volts at 500 Amps! Yikes. I can't imagine what a 500 Amp cable would look like. On Wikipedia, they say the Leaf QC port is capable of 62.5kW or a little over one fifth of the power. I would like to know how much current this charger supplies and over what kind of connector!

Yes - this is what the article doesn't mention.

Was it a stock Leaf or one with modifications ? But, even with some modifications to the cable etc, if they can pump that much current into the Leaf battery, that is indeed great.

BTW, chargers which operate @ 1000 V and 1000 A are available commercially now. But they need industrial grid connections.

 

[klapauzius]

If L3 charging at ~2 x the capacity degrades the battery faster, what will this do???
Also, how are they handling all the heat dissipation....but then its only 5 mins, so if you stop just in time, it wont melt the car :lol:

 

[TonyWilliams]

Kind of puts an upper bound on the viability of EV's for anything more than around town use. Not that that's a problem, just need to face facts.

This reminds me of the comments made at the turn of the 19th to 20th century... "everything that could be invented had already been invented."

 

[evnow]

Kind of puts an upper bound on the viability of EV's for anything more than around town use. Not that that's a problem, just need to face facts.

Yes you need a powerful grid connection (or have enough capacitors/batteries that can charge slowly, but discharge fast).

Even with all this, it will cost less to build a EV quick charge station than a gas station :lol:

 

[AndyH]

The 'good' news is that we don't have to consider the energy to add 24kWh to the battery because of the way lithium takes a charge.

The standard charge curve where the constant current (CC) stage (bulk charging) transitions to the constant voltage (CV) stage (saturation) is only accurate for one specific charge rate.

(This is only an example of a lithium charge/capacity curve. It is for LiFePO4, not for the LiMn2O4/LiNi cell used in the Leaf.)

In a really slow charge (L1), the CC/CV transition happens at a bit higher state of charge - maybe 80-90% ultimate. For an L2 charge, we might transition at around 70-80%.

Faster charge rates move the CC/CV to the left on the charge curve - the faster we push energy into the battery, the lower the state of charge at the CC/CV transition. In order for the battery to fully charge, it still needs to spend time in the CV stage - this saturation stage is required for lithium to reach higher states of charge.

A L1 or L2 charge can bring us to 100% consumer state of charge without having to slow much.
A DC quick charge can take us to about 80% consumer fairly quickly, but then has to slow the charge rate down if we want to charge to 100%.

A super-mondo-firehose-connected-to-a-nuclear-power-plant faster/quicker charge will go like a bat out of..well, really fast -- but only to about maybe 60% ultimate. The charger will have to slow the charge rate to work up to 80% or 100% consumer.

---
edit... Sorry to muddy the water here. The main point I wanted to highlight is that charging isn't linear - it's not like filling a 30 gallon drum with progressively larger diameter water hoses. Even though very slow charging appears to be linear, faster charges move the CC/CV transition point and require more time in the (slow) saturation phase to completely fill the battery.

 

[jimcmorr]

I did a quick calculation to charge a Leaf 24kWh battery in 5 minutes. It would require 288kW if my calculations are correct. This would be 576 Volts at 500 Amps! Yikes. I can't imagine what a 500 Amp cable would look like. On Wikipedia, they say the Leaf QC port is capable of 62.5kW or a little over one fifth of the power. I would like to know how much current this charger supplies and over what kind of connector!

Yes - this is what the article doesn't mention.

Was it a stock Leaf or one with modifications ? But, even with some modifications to the cable etc, if they can pump that much current into the Leaf battery, that is indeed great.

BTW, chargers which operate @ 1000 V and 1000 A are available commercially now. But they need industrial grid connections.

This link has a more detailed article than the summary article in the original post and is part of the summary article.
http://gas2.org/2011/06/18/new-tech-promises-fully-charged-evs-in-minutes/
and it says they were using a stock LEAF and battery. I personally think it is unlikely that sufficient power can be accomodated by the LEAF wiring on the QC port. Obviously the L2 port cannot be used for this purpose.

Last week, Kanno Tomio and his team of engineers in Tochigi, Japan have patented and demonstrated a new, ultra-fast charging system that fully charged a (production-spec.) Nissan Leaf’s battery pack in under 300 seconds (that’s 5 minutes to you and me).

The 'good' news is that we don't have to consider the energy to add 24kWh to the battery because of the way lithium takes a charge.

The standard charge curve where the constant current (CC) stage (bulk charging) transitions to the constant voltage (CV) stage (saturation) is only accurate for one specific charge rate.

(This is only an example of a lithium charge/capacity curve. It is for LiFePO4, not for the LiMn2O4/LiNi cell used in the Leaf.)

In a really slow charge (L1), the CC/CV transition happens at a bit higher state of charge - maybe 80-90% ultimate. For an L2 charge, we might transition at around 70-80%.

Faster charge rates move the CC/CV to the left on the charge curve - the faster we push energy into the battery, the lower the state of charge at the CC/CV transition. In order for the battery to fully charge, it still needs to spend time in the CV stage - this saturation stage is required for lithium to reach higher states of charge.

A L1 or L2 charge can bring us to 100% consumer state of charge without having to slow much.
A DC quick charge can take us to about 80% consumer fairly quickly, but then has to slow the charge rate down if we want to charge to 100%.

A super-mondo-firehose-connected-to-a-nuclear-power-plant faster/quicker charge will go like a bat out of..well, really fast -- but only to about maybe 60% ultimate. The charger will have to slow the charge rate to work up to 80% or 100% consumer.

Andy do you mean that it is not possible to charge a Lithium battery to 90% in 5 minutes? Is it possible that the charge curves are differant for the LiMn2O4/LiNi battery chemistry in the LEAF?

 

[evnow]

This link has a more detailed article than the summary article in the original post and is part of the summary article.
http://gas2.org/2011/06/18/new-tech-promises-fully-charged-evs-in-minutes/
and it says they were using a stock LEAF and battery. I personally think it is unlikely that sufficient power can be accomodated by the LEAF wiring on the QC port. Obviously the L2 port cannot be used for this purpose.

Last week, Kanno Tomio and his team of engineers in Tochigi, Japan have patented and demonstrated a new, ultra-fast charging system that fully charged a (production-spec.) Nissan Leaf’s battery pack in under 300 seconds (that’s 5 minutes to you and me).

That quote is even more ambiguous than I thought.

They recharged a production-spec Nissan Leaf’s battery pack. So, may be they didn't even use the car - they just took the battery and recharged it with whatever extras they needed added in (like a cooler).

 

[jimcmorr]

This link has a more detailed article than the summary article in the original post and is part of the summary article.
http://gas2.org/2011/06/18/new-tech-promises-fully-charged-evs-in-minutes/
and it says they were using a stock LEAF and battery. I personally think it is unlikely that sufficient power can be accomodated by the LEAF wiring on the QC port. Obviously the L2 port cannot be used for this purpose.

Last week, Kanno Tomio and his team of engineers in Tochigi, Japan have patented and demonstrated a new, ultra-fast charging system that fully charged a (production-spec.) Nissan Leaf’s battery pack in under 300 seconds (that’s 5 minutes to you and me).

That quote is even more ambiguous than I thought.

They recharged a production-spec Nissan Leaf’s battery pack. So, may be they didn't even use the car - they just took the battery and recharged it with whatever extras they needed added in (like a cooler).

Good point evnow. I totally missed that they conveniently excluded the car from that statement.

I guess this, like so many other things, is vaporware. It doesn't stand up to close scrutiny. They'd have to have had bus bars to carry the amount of power necessary to do this... if it is even possible in light of Andyh's research.