The Open CHAdeMO Charger Topic

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JeremyW

Well-known member
Joined
Nov 13, 2011
Messages
1,575
Location
San Gabriel, CA
Hi everybody! :)

As was discussed in my "almost the CHAdeMO Spec" thread, I'm quite interested in (legally) cracking CHAdeMO for us to build our own chargers. There's a bit of legal muck surrounding CHAdeMO, due to its closed nature. I've decided to go ahead and start "the" thread leading to our reverse engineering of this spec. First, the ground rule: if you know/have the spec but are under an NDA to not talk about it, please do not post here.

Ok with the lawyers happy (I hope), lets have some fun with chargers! And yes, no matter how you slice it, a CHAdeMO EVSE is a charger. :mrgreen:

The standard can be broken down into two parts, the analog side, and the digital or CAN bus side. Fortunately, the analog side is published right on the CHAdeMO website. I posted a more clear flowchart then what was published to make it really clear as to whats going on. I thought it was alright, but some thought it was so good that I must be looking at the standard! :lol: I wasn't; I just took what was on the website, nothing more. I don't have access to the standard. Anyways, here is is:

cATQ3.jpg


And here's a schematic, this is directly from the CHAdeMO interface.pdf available at chademo.com.

49ZFR.jpg


As you can see, the analog side is fairly simple. It's those dang CAN messages that we need to figure out. I know there's a few sniffing the QC port, so I hope this thread will allow you to come out of the woodwork. ;) I have made a Google code site for the project, available at http://code.google.com/p/open-chademo/. I will be updating it over the weekend. :)

Now, as far as generating the high power DC (and keeping it within 2% tolerance) this is sometimes done in one big switching mode unit, or is done modularity with separate smaller supplies. The hard part about this is that you need isolation, and that means running things through a transformer. Transformer size is proportional to switching frequency, so something in the high audible range or higher (I've heard 22 kHz is used, and I can clearly hear most of them), although the new Andromeda unit uses an even higher frequency to reduce size even further.

One very important warning: You can cause a fault condition if you muck around with this port and don't play by the car's rules. That being said Ingineer has done a lot of "experimentation" and has confirmed that most codes can be cleared with a 12v battery reset.

However, there is just enough knowledge in this thread to be extremely dangerous! You have been warned. Also, high voltage kills. This is serious, high power stuff and is meant to be mostly an academic exercise. It is not cost effective to build one of these for yourself at the moment. If you want a single phase and/or low power unit unit, talk to Ingineer about modifying a commercial unit for you.

Jeremy :cool:
 
So if the power fluctuates while you are using a chademo charger then its a trip to the dealership?.. sounds primitive.
 
With Nissan dropping their mass produced Q.C. price all the way down to $7,675 - I don't see how one could ever think that a home brew's price could compete.

According to Nissan, the "adoption of new electric circuit technology" allowed the automaker to create a quick-charge unit that's "simple and efficient" and costs only 598,500 yen ($7,675 US at today's exchange rate). Moreover, Japanese customers can apply to be partially reimbursed by the government, lowering the actual cost of the base unit (indoor use only) to an affordable 318,500 yen ($4,109 US).

http://www.plugincars.com/nissan-kicks-sales-4109-quick-charger-japan-110631.html" onclick="window.open(this.href);return false;

Several stats incentivize charger costs in the U.S. just like in Japan ... where the incentives bring costs down way below the $7k price. I'm hoping our compay (already on demand use rates) will install one for our customers.

.
 
hill said:
With Nissan dropping their mass produced Q.C. price all the way down to $7,675 - I don't see how one could ever think that a home brew's price could compete.
Alternatively, this could be used for a portable QC that could use more than the 16 Amps L2 allows. 7kW charging would then be possible from the 30A EVSEs or circuits, ~9kW from a 40A circuit, etc...
Such a unit may be less expensive than trying to upgrade the 3.3kW charger even if that becomes possible.
 
Meanwhile, Nissan and Sumitomo will launch an online charger ordering system in the US in January 2012. Installation of the DC quick-charge units will begin here in the States in spring of 2012.
 
Herm said:
So if the power fluctuates while you are using a chademo charger then its a trip to the dealership?.. sounds primitive.

I wouldn't think so. If you have a brownout, the power supplies would just draw more current. There are caps on the input and output that would give enough buffer. There are already switching mode power supplies on the market that have "AC fail" status that allows the controller to safely disengage before completely running out of power. CHAdeMO may be simple, but it is not primitive.

hill said:
With Nissan dropping their mass produced Q.C. price all the way down to $7,675 - I don't see how one could ever think that a home brew's price could compete.

That's not exactly who we're trying to "compete" with here. Nissan (or any other commercial CHAdeMO out there) uses 3 phase AC at 208V or higher, which is not available in a residential setting. I'm hoping for something in the 10-20kW range like 91040 mentioned, perfect for a multi-ev household with a leaf or two with a 3.3kw onboard. Making something like this would surely be less expensive then upgrading the onboard charger, and would let you even beat a 2013 Leaf with a 6.6kw.

I'd also like to point out that if we can get this standard open, then it would be very valuable to the DIY electric car market. If they can use CHAdeMO as well, then that would increase demand for more stations. It could also conceivably save them money by not requiring a charger at all, just a BMS.

Jeremy
 
Finding the "normal-operation" Chademo-CAN message-handshaking might not be too difficult.

Finding out how the Chademo CHARGER (it is not an EVSE) is to handle a sudden power outage to avoid disabling the attached car ... is much more difficult.
 
I called my contact at AV (the distributor), and Nissan Customer Service, and nobody knows anything about the Nissan / Sumitomo charger yet.

More troubles in paradise.
 
garygid said:
Finding out how the Chademo CHARGER (it is not an EVSE) is to handle a sudden power outage to avoid disabling the attached car ... is much more difficult.

True. Then again, there's an emergency stop button on the commercial CHAdeMO chargers, that should kill the power pretty quickly. There has to be an "easy way out" that doesn't freak out the car. Someone hit the emergency stop when you're charging next time, and see what happens. ;) :lol:

Not to split hairs or anything, but isn't a charger a piece of "electric vehicle supply equipment," Gary? It's supplying the charge, after all... :mrgreen:
 
Oh boy, update time! :D

There’s been work done on the CAN messages. Gary sums it up best (from his QC Message Decoding Thread)

garygid said:
Messages on the QC CAN-bus:
(from observation of our QC-CAN traffic logs)

1. Messages 100, 101, and 101 seem to come from the LEAF.

2. Messages 108 and 109 seem to be replies from the QC machine.

By "simulating" a QC machine's first step after being connected
(apply +12v to a control pin), the LEAF sends 100, 101, and 102.

This "group" seems to be repeated about 10 times per second,
but it appears that the car gets "tired" of waiting for a response
in about 2 seconds, and it quits sending.

In operation, the car sends the current (in amps) that it wants
in an "Amps-Requested" byte in this group (0 to 120 observed).

Here's a graph of the 109 values from a typical session. Notice "series 4" is charging amperage:
YkZSx.jpg


There's more to come on that front. :twisted:

I also wanted to discuss a few of the discrepancies between what I’ve seen at my nearest CHAdeMO station, the Eaton unit at Misubishi’s headquarters in Cypress, Ca. and gas station pumps. As we know, most people will charge at home. I know this, you know this, but for Joe public, his main interaction is with a gas station. It is engrained into the mind of the public that your energy source for your vehicle comes from somewhere that you have to drive to. This is why Level 3 stations, CHAdeMO or otherwise, should be treated as the flagship of the electric car world. They need to compete with the gas pump in ways that it can’t. One of these ways is the ease of connection.

I will come out and say that I do not like the handle design that is used by CHAdeMO. I have seen both the “two leaver” and the “one leaver, one button” implementations.

R75ox.jpg


eMZeq.jpg


I really do not like these because we are so use to UP means ON and DOWN means OFF with a gas station nozzle, most trying out a CHAdeMO station would attempt to push the bottom leaver down when they are finished charging. This has the effect of straining the leaver on the CHAdeMO connector, as you are suppose to push the black button on top (or the side red leaver) to disengage everything, and the leaver comes down on its own. Ugh. If we are to stick to a gas nozzle look alike, then we better act like it too, because that’s how the public will attempt to use them. This is America; we ain’t reading no stinkin’ directions. ;)

I’m no mechanical engineer, but if I was to implement something that matched the TEPCO connector on the leaf, I would go for a “one button” solution. Have the charger side just be a nice handle to grab on to with a red stop button on it. The locking of the connector and pushing in the pins would be handled by servos, not leavers. This allows for a much stronger handle design then the current leaver solution. Like this:

5rvDf.jpg


Jeremy :cool:
 
Very nice pictures of the old (red lever on the side) and
the newer (no red lever) Chademo "nozzles".

Although some folks are intimidated by using gas pumps and their nozzles,
the usually learn easily (if willing to do so) from a gentle teacher.

In the same way, fueling with E-fuel requires a new skill,
both at the "pump" and at the car.

This "skill" is not difficult to learn,
no matter what the "nozzle" looks like. :D

But, yes, some are "stranger" than others. :eek:
Easy for Japanese, but apparently difficult for some Americans. :(
 
Well, on Saturday I was able to make it down to the San Diego Leafers meeting in Poway using my ICE. I had a bit of range anxiety due to running really low on gas on the way, but I was able to get a tank full for the low low price of $4.29/gal! :? A very good time was had, and man there are a lot of leafers down there! Everything is also really spread out, worse than Orange County. It seems they need quick chargers NOW. I guess I'm lucky to have Mitsubishi's charger available. Too bad I don't own a leaf yet. :lol:

During the discussion it was brought up that RV parks have a pretty good setup: 50 Amp 240 service available, they know how to charge for electricity, they're near freeways, and *most* of the permitting is already done for us. So the point was made that why can't we get a rapid recharger at every facility to jump start our nation's electric car charging infrastructure? Well, first, all of the current chargers need 3 phase, and for understandable reason. 62.5kW is a LOT of power. But I brought up a question: how fast is fast? Would it be ok if the charging time was a bit longer then 20-30 minutes? How about 45? An hour? I also mentioned that I'm currently monitoring these charging sessions, and the amount of time spent at 62.5kW is actually quite short if you're starting from a fairly high SOC. There's nothing electrically preventing you from making a lower power CHAdeMO charger, single phase or other wise. You just have to be isolated and follow the rest of the spec. The max perimeters of the charger are sent at the beginning and every 100 ms. It's the car's job to work with what it has attached to it.

Here's a graph of a charge, initiated at ~50% SOC, and ended at ~90%.

oJtLq.jpg


Notice how long it stays at the max current (120 Amps, not even the full spec 125)- about 70 seconds. It drops off fairly quickly. I haven't found pack voltage but I think I’ve found battery SOC, expressed as .1 kwh per bit, and if that’s the case the session put 8.5KWh into the pack. (1/.4)*8.5kwh=21.25KWh, which seems about right. If this had been a slower CHAdeMO charger, set at 10KW, this session would have taken about 51 minutes. Of course that is assuming that the car isn’t limiting the current below 10KW during that session; specifically, between 80% and 90%. I’d imagine going much higher then 90% SOC, the car will start backing down the current to below L2 levels. Besides, don’t you guys like your regen? ;)

I can’t stress enough that we need a single phase CHAdeMO charger. 3 phase power is available in America, but it’s not as common as Europe or Japan in a light commercial environment, and is totally unavailable residentially. We have places that have ample single phase capacity that could totally set these up (RV parks). If that means we only get 10-20kw so be it. Its at least better then 3.3kw.

Jeremy :cool:
 
JeremyW said:
. . . . . . . . . . snip
I can’t stress enough that we need a single phase CHAdeMO charger. 3 phase power is available in America, but it’s not as common as Europe or Japan in a light commercial environment, and is totally unavailable residentially. We have places that have ample single phase capacity that could totally set these up (RV parks). If that means we only get 10-20kw so be it. Its at least better then 3.3kw.

Jeremy :cool:
Jeremy, It's not really that big a deal to convert residential single phase to 3 phase. My dad & I did it at his Bellflower home (garage), over 20 years ago, just so we could run a couple pieces of commercial machining equipment. See example here:
http://www.ebay.com/itm/PHASE-A-MATIC-R-10-ROTARY-PHASE-CONVERTER-10-HP-/120755211866?pt=BI_Electrical_Equipment_Tools&hash=item1c1d924e5a#ht_5150wt_958" onclick="window.open(this.href);return false;

There's an acceptable bit of loss going from single to 3 phase ... no big deal. So - "totally unavailable"? Maybe it'd be better to say it's a bit of a hassle. But it is do-able.
 
Jeremy, please see THIS thread about CHAdeMO @ RV Parks. There is a lot of discussion there.

BTW: RV parks almost always have 3-phase already. 3-Phase is more common than you imply, and in addition, there is no specific requirement for 3-Phase in the QC. I can readily convert any 3 phase QC to operate on single phase for a nominal fee, although there will likely be a bit of a derating. (this will vary depending on how the power stage is implemented.)

The Last 2 RV parks I visited were larger affairs and were fed with 480v 3-phase. They ran 480v feeders to small clusters of parking spots where there was a local transformer with the breaker box attached to it. These small local transfomers were configured to output 3-phase 208/120v (wye).

-Phil
 
hill said:
Jeremy, It's not really that big a deal to convert residential single phase to 3 phase.
There is no need to convert to 3-phase, as the QC simply rectifies (usually with a PFC front end) the AC input to a DC bus. This DC is few to a high-frequency switch-mode transformer which provides the required isolation and allows the charger to dynamically adjust it's output.

Note that most residential power systems simply could not handle a full CHAdeMO QC load (~50kW) as the transformers feeding them are usually around that size or smaller, and typically feed several houses, let alone the fact that the individual feeders/meter are usually 200A or smaller. (With a 200A panel, 48kW would be the largest possible load if everything else in the house was off, and that doesn't include any derating!) You try to put a QC load on almost any residential system, and you'll be in the dark pretty fast!

-Phil
 
Ingineer said:
There is no need to convert to 3-phase, as the QC simply rectifies (usually with a PFC front end) the AC input to a DC bus
Right. The point I was trying to make is that there isn't a single phase unit available, and there isn't anything that says one couldn't exist. That's what I was implying with the "need" for single phase, lower power, CHAdeMO. A single phase unit, say 10kw, could hook in to the 14-50 in a stall and be good to go. I've talked to several people who'd love a portable or maybe luggable 10-20kW unit with single phase 240 V input. There was a 12 page topic on this. The demand is there. Until we get 6.6+kw on board j1772, this is the solution to "sorta fast" recharging, or if you prefer, "avoiding the demand charge" recharging. I've been following that RV park thread too. I lurk a lot on here. :)

I also wanted to explain how long the car will try to draw (request) max current, and show how it does ramp down quickly at higher SOC, faster then I think most people would expect. It is not just 62.5kw to 80%.

Jeremy :|
 
I have been working on a medium-power solution, and have built some prototype testers, but the cost is still simply too high to consider. For instance, my cost on the CHAdeMO connector/cable is well over 2 kilobucks alone! By the time you add in all the power electronics, which aren't cheap, and then try to recoup some of your one-time and development costs, and you are getting close to Nissan's proposed $8k 50kW unit, and this of course doesn't include a UL listing! They can afford the huge up-front investment and wait a long time for payback, whereas I can't. They also have massive buying power and a full supply chain to get the expensive components a lot cheaper and faster than I can. Plus, they may even be do it at a loss, because they know it will spur their EV sales long-term if they can get the QC infrastructure out there ASAP!

It may actually turn that the lowest cost way for me to offer a residential or small business "medium" rate charger, is to buy the Nissan unit and upgrade (downgrade) it!!! :shock:

Because of this, I have, at least for now, abandoned by efforts at producing my own "MC". I have one of the multi-kilobuck Yazaki CHAdeMO cables for sale now if anyone is interested! :) The sooner I can recover some $ from that project (a lot was sunk into it), the sooner I can move onto other more exciting things!

-Phil
 
Alright, lets talk CAN. :)

There are 5 different ID's on the CAN bus. Each message has an ID and 8 bytes of data. Three are the car, two are the charger. The car ID's are 100, 101, and 102. The charger ID's are 108 and 109.

[Edit: See page 3]

Note the static bytes may be fault or other status flags. There's still more logs and more investigating to do. :)

Jeremy
 
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