Charge LEAF Battery in 5min!

[LTLFTcomposite]

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!

Even picking up 50 miles of range in an hour of charging isn't going to do you much good on road trips. We have been known to go over 800 miles before stopping to sleep (particularly in areas where the woods are lovely) so certainly you see charging en route just isn't going to work, unless the charging can be done at overnight stops. When battery capacity gets up to the 500+ mile range now you're talking... approaching a human's capacity to sit in a car

 

[AndyH]

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?

Not trying to say it's not possible - there are many lithium cells on the market capable of a 6 minute charge (that's a 10C rate) - we don't need any new tech on the battery side for quick charges.

Yes - the charge curve is different for the Leaf's battery - but the concept of lithium cells transitioning from CC to CV holds across the lithium family (and applies to lead-acid as well). The transition point moves, and the CV stage must progress more slowly than the bulk charge phase.

The real limit is in the power supply feeding the car (and now as we've seen, the car wiring).

 

[LEAFfan]

Even picking up 50 miles of range in an hour of charging isn't going to do you much good on road trips.

No, but charging to 90% in five minutes sure will. I wouldn't mind driving 80 miles or so and then taking a five minute break. Your range would be limitless.

 

[MikeD]

I may have missed a post where this is mentioned, but does anyone know what is the gauge of the two DC charging wires leading from the QC port to the battery pack (and perhaps the temperature rating of its insulation)? That should give us a good idea what its ampacity is according to NEC.

 

[jimcmorr]

Thanks Andy!

I may have missed a post where this is mentioned, but does anyone know what is the gauge of the two DC charging wires leading from the QC port to the battery pack (and perhaps the temperature rating of its insulation)? That should give us a good idea what its ampacity is according to NEC.

Another way to look at this question is to define what might be required of a conductor (gauge size and insulation temp rating, etc) to charge this battery at this rate for five or six minutes. We could then decide if it is reasonable to think (reasonable man approach) the conductor in the LEAF is capable of this task.

 

[evnow]

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.

I wouldn't call it vaporware - but definitely some important details have been lost in translation.

 

[jimcmorr]

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.

I wouldn't call it vaporware - but definitely some important details have been lost in translation.

Okay. Perhaps it is more accurate to call it a proof of concept. In any event it would seem a long way from commercial application. We can't even get the CHAdeMO chargers in place here.

 

[MikeD]

Eyeballing one of the two L3 cables I get ~11.5mm, which leads me to guess that no thicker than 1/0 copper wire is being used (insulation temperature rating unknown). If I am correct the 2008 NEC would suggest that the allowable current capacity is about ~140a, assuming 90 degree C insulator temperature rating and ambient temperature as high as 114-122 degrees F.

This seems in line with Level 3 charger specifications I have seen of 125a at 500v.

I can't see that 1/0 wire could support a significantly faster charging rate, certainly not 5 times as fast as is the claim in the OP link...

 

[DrRocket]

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."

Well they were a little early. But it is true now. :lol: Really, it is different this time.

 

[Nubo]

Even picking up 50 miles of range in an hour of charging isn't going to do you much good on road trips. We have been known to go over 800 miles before stopping to sleep (particularly in areas where the woods are lovely) so certainly you see charging en route just isn't going to work, unless the charging can be done at overnight stops. When battery capacity gets up to the 500+ mile range now you're talking... approaching a human's capacity to sit in a car

I agree that a real 500+ range would be the final nail in the coffin of "range anxiety". But too many people assert that EVs "don't make any sense" until the proverbial "Great American Road Trip" can be had in an EV.

That's a problem that will be solved as a matter of course over time. In the meantime it doesn't invalidate EVs advantages for millions of owners. For those of us with more than 1 vehicle, or who aren't traveling salespeople, EVs make plenty of sense even at the range of the LEAF.

I once drove solo nonstop from Los Angeles to Cleveland in 37 hours. But I don't hold that as a standard that EVs must meet at this time.

 

[garygid]

I do not know where "pad..." came up with the 5 ohms for the cables, but it is more likely that they are only 0.005 ohms, or even less.

Five ohms at only 100 amps would lose 500 volts just in the wires alone, leaving nothing for the 400v battery pack.

 

[aqn]

I know zilch about batteries. What I know about batteries I read on here (which means I still know **** about batteries ).

But, even with some modifications to the cable etc, if they can pump that much current into the Leaf battery, that is indeed great.

That's basically my understanding, that one can only shove so much electricity into a battery in one unit of time. I think I have read that this is why 1. the re-gen rate gauge is capped at 30 kWh and 2. one does not gain back going down a hill anywhere close to what one expends going up the same hill (at a semi-reasonable speed).

Such being the case, why is it possible to recharge the LEAF's battery in five minutes?