maybe.... a lot will depend on the impact of regular fast charge on the Leaf and the negative press that exists at that time... it sounds as if a lot of UK Leaf drivers are already ignoring the "once per week" advice...
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I completely disagree. DC chargers should be set up alongside major highways for use on longer road trips. If that is done there will be no advantage to driving an ICE car.
Norbert
TSLA will win
Forget 3-phase 44kW for fast charging future battery packs. DC fast charging can conveniently double and triple your single-day range. No other technology can do that.
Guys...
Look at the various presentations that are posted on this board and the specs from manufacturers and standards groups and you will see the AC cut off is at around 50kW. This is mostly due to the size and cost of the rectifiers etc. For Model S (and others) to get 45 minute charging in a 230 mile battery it's going to have to be higher than that. So there is a need for DC at main rest stops for that speed of charging.
However you can get 80% of the functionality for <20% of the cost with three phase AC and so in countries whose grids support it, you will undoubtedly also see this type of charging get set up too. That will be in Germany, Netherlands, Switzerland etc in a residential setting and all of Europe in a commercial setting.
We are already seeing this mixed scenario in the UK, Ireland and the Netherlands.
Look at the various presentations that are posted on this board and the specs from manufacturers and standards groups and you will see the AC cut off is at around 50kW. This is mostly due to the size and cost of the rectifiers etc. For Model S (and others) to get 45 minute charging in a 230 mile battery it's going to have to be higher than that. So there is a need for DC at main rest stops for that speed of charging.
However you can get 80% of the functionality for <20% of the cost with three phase AC and so in countries whose grids support it, you will undoubtedly also see this type of charging get set up too. That will be in Germany, Netherlands, Switzerland etc in a residential setting and all of Europe in a commercial setting.
We are already seeing this mixed scenario in the UK, Ireland and the Netherlands.
Norbert
TSLA will win
I don't know if as much as 44kW is possible without increasing the cost too much. If it is, then that is fine as medium-speed charging.
Charging rates much higher than that. DC fast charging technology will evolve quickly (power and cost), but needs to start now. The 300 mile pack will very likely already support higher charging rates, perhaps much higher, and the next generation packs will most likely support even more (unless artificially restricted because infrastructure isn't available).
For EVs to become mainstream, we'll need everything that is possible (for the foreseeable future), and reduce costs on top of it.
stopcrazypp
Well-Known Member
Keep in mind even with 3-phase you still need the actual charger on-board. I couldn't find a demo vehicle that supports 44kW 3-phase charging (maybe someone has an example). I mentioned in the Chademo thread: the main reason why CHAdemo was able to gain traction was because TEPCO demonstrated long ago the system actually working in an EV. I think the German roll-out for 44kW 3-phase stations is 2014-2017 (although in the meantime IEC 60309 will work for most people) and who knows how many Chademo (or other DC) stations there will be by then.
Given automakers struggle including 6.6kW chargers (the Leaf only has 3.3kW), I don't think a 44kW on-board charger is trivial. I would be interested if anyone can find the cost comparisons between different power on-board chargers.
I feel DC charging is necessary because it has the highest power limit. Once you have big enough battery packs (Model S 300 mile pack for example), even at 0.5C charging (typical even in relatively slow charging 18650s), you can already exceed 44kW. DC charging is the only fast charging solution that can get close to parity with gasoline refilling.
The clear trade off between the two:
DC: charger per location, more expense per location
3-phase: charger per car, more expense per car
Short term, with similar power (50kW CHAdemo being the leading DC) and relatively low volume/short range EVs, the 3-phase is better, since it means more/denser locations, even if the car is more expensive.
Long term, with DC providing more power and high volume/long range EVs, DC is better (closer to gasoline refilling). It means less/sparser but faster charging locations, and a less expensive car (instead of having millions of expensive on-board chargers, you have something like hundreds of thousands of expensive off-board chargers). And any charger upgrade is done on a location basis instead of per car.
So best solution (works for both short and long term) it seems is to support both, which I think the IEC is trying to do by adding extra DC pins to the Mennekes connector.
Given automakers struggle including 6.6kW chargers (the Leaf only has 3.3kW), I don't think a 44kW on-board charger is trivial. I would be interested if anyone can find the cost comparisons between different power on-board chargers.
I feel DC charging is necessary because it has the highest power limit. Once you have big enough battery packs (Model S 300 mile pack for example), even at 0.5C charging (typical even in relatively slow charging 18650s), you can already exceed 44kW. DC charging is the only fast charging solution that can get close to parity with gasoline refilling.
The clear trade off between the two:
DC: charger per location, more expense per location
3-phase: charger per car, more expense per car
Short term, with similar power (50kW CHAdemo being the leading DC) and relatively low volume/short range EVs, the 3-phase is better, since it means more/denser locations, even if the car is more expensive.
Long term, with DC providing more power and high volume/long range EVs, DC is better (closer to gasoline refilling). It means less/sparser but faster charging locations, and a less expensive car (instead of having millions of expensive on-board chargers, you have something like hundreds of thousands of expensive off-board chargers). And any charger upgrade is done on a location basis instead of per car.
So best solution (works for both short and long term) it seems is to support both, which I think the IEC is trying to do by adding extra DC pins to the Mennekes connector.
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How big and heavy would a 44kW charger be?
Web searches turn up external bulky/heavy units like this:
ePona EVC-700 battery charger
(Weight: 80kg)
Web searches turn up external bulky/heavy units like this:
ePona EVC-700 battery charger
(Weight: 80kg)
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Well, I would happy with 22kW onboard and the rest via DC, no problem for me, but we also have to be realistic. 1-phase would be idiotic, since that would render the car useless in areas where there are no DC chargers around.
I've seen mention of 200A charging in this thread. I have some 200A banded cable and it's very heavy and awkward. A single cable like the one for the 70A charger would likely be so heavy that very few people would be able to lift it comfortably and safely connect it to the car. I think slight people would find it completely impossible. The weight of the cable would have to be supported from above to make it even remotely realistic. Even the 70A charger is too much when it's very cold! (That vinyl material it's made from gets incredibly stiff in Minnesota cold).
Norbert
TSLA will win
Be that as it may, at least some Leaf users are really proud of being able to use it. Model S will have different battery chemistry, and we don't know yet what Tesla will tell us about fast charging for the Model S, and which maximum fast charging rate the Model S will support. Even less we know about next generation chemistries. I'm in favor of supporting all options, specifically high rate J1772 + high rate DC charging in the US, and (apparently) 22 kW or, if feasible, 44kW 3-phase Mennekes + high rate DC charging in Europe. Not only, but also, since that is the *kind* of thing Tesla appears to consider possible.
Instead of telling people that unless home-charging is sufficient, EVs are not for them, I hope we will soon be able to say that an EV is for you if *either* home (+work) charging is sufficient, *or* if fast-charging is available where and when you would need it (usually not on a daily basis). Currently in the US a number of 7kW J1772 chargers are being installed (instead of the possible 17 or so kW) and they may help as well, but I think with them you'll have to calculate a lot how much time you are willing to spend at each charging station.
Or am I too optimistic about EVs becoming a convenient choice for almost everyone, quite soon? I think this is a really good time to start approaching all these enabling technologies, such as high rate DC fast charging, which will need to be approached sooner or later. I'd rather not bet on the rising oil price to solve all these problems magically. We may still have enough time to experiment a little, choose the best solutions, and make a few errors, but the time may come when we are forced to make really bad compromises unless we are ready.
Agree with you completely on the "home charging only" issue. That crowd is living in their own little niche. If it works for them, great.
The technology for rapid charging has all been shown, it just needs to be comercialised.
By the way, what's the weight of the PEM?
The technology for rapid charging has all been shown, it just needs to be comercialised.
By the way, what's the weight of the PEM?
I completely agree... my main point is that we will undoubtably have some bad press when users who use DC Fast charge regularly have battery degradation problems on the Leaf.
The Leaf is clearly not designed for regular DC Fast Charge and that message must be managed if we are to avoid serious kickback from the mass market.
Norbert
TSLA will win
The last I heard is the degradation is still within a certain range even if you were to use it daily. The Leaf is obviously designed to use fast charging when needed, and that is perceived as a big advantage, including by the press. I'm not even sure why you stress this point so much. Clearly, Tesla sees it as a major selling point for the Model S as well.
Norbert
TSLA will win
There seems to be some tradition of thinking that is suspicious of fast charging and says: either "home charging only" or a hybrid. My best guess is that it is coming from utilities who worry that they would have to upgrade some cables/transformers without getting an immediate return-on-investment, and are not confident yet that EVs aren't just a fad that will go away soon and their investments are for nothing. Perhaps that's still from the EV1 time. Don't know.
Is this question for Zack? I'm not getting the connection. The Model S PEM?
My feelings, and those I hear, are suspicious of fast charging because of (a) long-term damage to or affect on the life of the battery, and (b) not seeing a requirement.
Now, (b) is certainly because of where I live, but also affects the scalability of EVs as common transportation. If you have a big enough battery to get through a day, then you don't need fast charging - an overnight at home or in a hotel is fine. Assuming an explosion in the numbers of new EVs with smaller batteries relying on fast charging to get through the day - we'll end up with so many EVs that every parking spot will have to have a fast charger. I just don't see how that is scalable.
What is interesting is the fast-charger at the motorway rest stop. Somewhere you could break a trip to have lunch and refill the battery. That would close to double your range (for a given battery size) - but I still worry about all the infrastructure needed to support tens or hundreds of thousands of these.
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