Public charging

[BernieTx]

But what would the point of that be? Just to save the weight of an OBC? And how will you charge at home? How many homes have DC 480 volt capability? So you'll still need some sort of device to convert that incoming AC current to DC, and double the voltage as well. And how will you charge the tens of thousands of existing EV's that were designed with J1772 in mind, but have no DC port?

It's already been a challenge to get the existing public L2 infrastructure in, and to educate the public about the various charging standards, now you want to add yet another set of standards to the ones that currently exist? It will make the confusion over VHS/Beta, and more recently Blu-ray/HD-DVD, absolutely pale by comparison.

As far as a combined L1/L2/QC port, that already exists in the form of CCS, aka "FrankenPlug." Of course we know how well that was received on this forum :lol:

Newbie: what is a FrankenPlug? I know that Tesla has their own plug different from the Nissan J1772 plug. I think the Volt uses the same one as the Nissan... not sure why they don't all use the same plugs. I don't know if there are adapters...

 

[TimLee]

Newbie: what is a FrankenPlug? I know that Tesla has their own plug different from the Nissan J1772 plug. I think the Volt uses the same one as the Nissan... not sure why they don't all use the same plugs. I don't know if there are adapters...

The SAE adopted standards.
See http://www.mynissanleaf.com/viewtopic.php?f=26&t=8280&hilit=sae#p183208" onclick="window.open(this.href);return false; and http://www.mynissanleaf.com/viewtopic.php?f=10&t=8968&hilit=sae#p200821" onclick="window.open(this.href);return false;.

 

[RonDawg]

[Newbie: what is a FrankenPlug? I know that Tesla has their own plug different from the Nissan J1772 plug. I think the Volt uses the same one as the Nissan... not sure why they don't all use the same plugs. I don't know if there are adapters...

FrankenPlug is the moniker often used by supporters of the CHAdeMO fast charging standard (which is what the Leaf, iMiEV, and Kia Soul EV use, and what is deployed across Japan) to describe the CCS/SAE Combo fast charging system. Basically, it's a standard J1772 plug with an extra two prongs (for the DC charging system) added just below it:

The charging handle does look a bit unwieldy, which is probably where the name came from:

Article on the controversy over CCS: http://www.longtailpipe.com/2014/01/evgo-deploying-frankenplug-fast.html" onclick="window.open(this.href);return false; J1772 is the standard adopted in North America for EV's today for both L1 and L2 charging. Teslas, and older EV's like the GM EV-1 and 1st gen Toyota RAV4 EV, are the exceptions.

I will publish a correction on what I said earlier to Slow1: apparently CCS does support DC non-fast charging, so no need for another standard. Of course someone will probably try to come with one anyway (Apple, if the rumors are true, will almost certainly be one).

 

[TimLee]

But what would the point of that be? Just to save the weight of an OBC? And how will you charge at home? How many homes have DC 480 volt capability? So you'll still need some sort of device to convert that incoming AC current to DC, and double the voltage as well. And how will you charge the tens of thousands of existing EV's that were designed with J1772 in mind, but have no DC port?
...

I agree that DCQC at home is not likely to be cost effective any time soon.

But most DCQC use AC power and do the rectification.

So the home would require step up transformer. Even my dealer had to add transformer.
Even though the business had three phase power, all they had was 120V and 208V.

And even a 10 kW DCQC will be pretty costly.
So $3K for transformer, and maybe $3K or $4K for a 10 kW DCQC if anybody was building them.
Most people will not spend over $7K for doing 10 kW DCQC at home.

Once a 200 mile (or more likely a real 150 mile range) vehicle is available at a reasonable cost, there may be more interest in 10 kW home charging.
But still more likely it will be done with on board charger, not DCQC at home.

 

[Slow1]

But what would the point of that be? Just to save the weight of an OBC? And how will you charge at home? How many homes have DC 480 volt capability? So you'll still need some sort of device to convert that incoming AC current to DC, and double the voltage as well. And how will you charge the tens of thousands of existing EV's that were designed with J1772 in mind, but have no DC port?
...

I agree that DCQC at home is not likely to be cost effective any time soon.

But most DCQC use AC power and do the rectification.

So the home would require step up transformer. Even my dealer had to add transformer.
Even though the business had three phase power, all they had was 120V and 208V.

OK, so back up a step or two here. I am not suggesting DC_QC_ at home, rather simply DC charging. The OBC basically converts the AC to DC to charge the battery anyway, I am suggesting save the weight of this in the vehicle and stick it outside. Not "Quick' charging perhaps, but a common port to the car could be used for the slower or faster. If you have used a DCQC (I'm on one as I write) you will know that the amount of power decreases as you charge so clearly the DC port can handle lower power levels. So the home units would max out at 6-7Kw and I don't believe it should require a greater feed than is available currently with 240v 50a circuits.

@timlee - the point of this is twofold. First, yes save the weight of the OBC when driving which may lighten the car (I'm sure someone here can quantify if this is enough to matter). Second point is EVs then become more 'universal' in terms of what they can handle - if all have a DC port they we don't ahve 3.3/6kW variations out there.

Yes, if the market would go this way then existing vehicles may lose out - Frankly I have to assume all of us are likely to find ourselves with obsolete plugs/standards anyway. It is a fact of live in being an early adopter isn't it?

 

[edatoakrun]

quote="Slow1"... I am not suggesting DC_QC_ at home, rather simply DC charging. The OBC basically converts the AC to DC to charge the battery anyway, I am suggesting save the weight of this in the vehicle and stick it outside. Not "Quick' charging perhaps, but a common port to the car could be used for the slower or faster...

There are threads going back ~four years where the obvious has been posted, that it makes no sense whatsoever to install the AC charger on the vehicle.

Yes, at some point in the future all BEVs (and PHEVs, if they still exist) will accept only a DC charge, either from a public charger or your home charger, designed to simultaneously charge as many BEVs you require.

This is predestined not only by the cost benefits you mentioned, but also by efficiency, as getting the charger off the vehicle enables the waste heat to be recoverable for other purposes, which will be increasingly important for public chargers, with multiple DC sites, where the waste heat is currently considered a problem.

Consider the benefits of recovering the hundreds of kW of waste heat from dozens of fast-charging BEVs at a public charge site, to supply water or space heating to the adjacent businesses.

="Slow1"...Yes, if the market would go this way then existing vehicles may lose out - Frankly I have to assume all of us are likely to find ourselves with obsolete plugs/standards anyway. It is a fact of live in being an early adopter isn't it?

Actually, this is one of the reasons I believe the CHAdeMO DC approach is superior to the SAE combo DC port, which compromises its design for an obsolescent (AC charging) purpose.

So I expect that CHAdeMO has a better chance of lasting as a public standard, at least for a while.

And in ~ five or ten years, the AC charging system on my LEAF may just be something I won't have to worry about fixing if it ever fails, once I have a CHAdeMO DC charger at my home.

 

[Levenkay]

The OBC basically converts the AC to DC to charge the battery anyway, I am suggesting save the weight of this in the vehicle and stick it outside. Not "Quick' charging perhaps, but a common port to the car could be used for the slower or faster.

Here's another capability that "the car had to have anyway": the ability to convert large amounts of AC power into DC high voltage for recharging the battery during regenerative braking. I'm probably blithely ignoring many important details here, but for me, just what the car already does is borderline magical, so why not more? According to the dashboard bubbles, the regen capability used to be comparable to a DCQC rate (whyever did Nissan cripple regen without placing a similar restriction on DCQC?), which ought to say that if a relay or solid-state switch substituted the AC mains for the power conversion module's motor terminals, the PCM ought to be able to "regenerate" from the grid at DCQC-comparable rates. And, going the other way, it ought to be able to "drive" the grid from the battery to provide "vehicle-to-grid" capabilities for energy storage or emergency home power. Yes, there are safety issues that will call for absolutely bulletproof software. Has anyone heard about the pushes to develop self-driving cars (brrr!!) ?

In light of the above, I feel that it's the car's DC interface that's doomed to obsolescence, not the AC one. Tesla was right, again.

 

[mjblazin]

I have read through the charging posts and do not see a definitive answer on impact of Quick Charge on long term battery health. I disregard the comments from people leasing since I own.
Is safe to routinely QC or must it simply be an emergency, get enough juice to get home or to an L2 charger? Is it ok on a cold day but avoid on a hot Dallas summer day since the accelerated energy transfer will exacerbate the battery temp problem?

 

[desiv]

I have read through the charging posts and do not see a definitive answer on impact of Quick Charge on long term battery health.

Been mentioned several times on this forum, but it looks to not be much of a problem.
Heat appears to be the major risk. DCQC can raise the battery's heat, so it's something (the battery heat) you'll want to watch, but apparently not the issue they thought it might be..
http://www.autoblog.com/2014/03/17/dc-fast-charging-not-as-damaging-to-ev-batteries-as-expected/" onclick="window.open(this.href);return false;

I disregard the comments from people leasing since I own.

Hmm.. I read something once about flies and honey... ;-)

Is safe to routinely QC or must it simply be an emergency, get enough juice to get home or to an L2 charger? Is it ok on a cold day but avoid on a hot Dallas summer day since the accelerated energy transfer will exacerbate the battery temp problem?

As mentioned, it is most likely fine, but you should watch the battery temp if you live in a hot climate.

desiv
p.s. I do own, so if you're going to disregard my post, it should be for some other reason.. ;-)

 

[mjblazin]

Thanks for info. My reference to people leasing stemmed from more than a few comments that the long term for them was 3 years. If it hurt the battery, not their problem.

 

[TimLee]

I have read through the charging posts and do not see a definitive answer on impact of Quick Charge on long term battery health. ...

Hard to quantify with data.
I have done a lot of DCQC.
Near 160 in 47 months.
And may have impacted my capacity more than someone who never did DCQC.

Clearly DCQC typically raises measured battery temperature by 6F to 10F.
And temperature is the most significant factor on battery pack capacity degradation.
So it is a negative.
But to quantify that impact is a very big challenge.