Level III charging a Leaf

[JimK]

I am an electrical engineer looking for information on Nissan’s level III quick charge capability. I believe they use a TEPCO connector and the CHAdeMO communication protocol but can not confirm this. I’m also looking for technical information/specifications on the communication protocol between the EV and the charging station. Any assistance would be greatly appreciated.

JimK

 

[DrPowell]

I am an electrical engineer looking for information on Nissan’s level III quick charge capability. I believe they use a TEPCO connector and the CHAdeMO communication protocol but can not confirm this. I’m also looking for technical information/specifications on the communication protocol between the EV and the charging station. Any assistance would be greatly appreciated.

JimK

Yes, 2011 LEAF uses TEPCO and CHAdeMO. Check the documents sticky thread for links or PM AndyH.

 

[garygid]

Does one have to join the ChaDeMo "association" to get the technical protocol info?

I also am EE and want the same L3 (QC) info.

 

[Coffee_Slurry]

I've searched for public documents and come up empty.

If anyone has the full implementation details for CHAdeMO, post up!

 

[UhClem]

It appears that CHAdeMO uses CAN-bus for signaling:

From http://chademo.com/indexa.html:

The CHAdeMO quick charger design has a controller that receives EV commands via a CAN bus, and the quick charger sets the current to meet the EV’s command value. Via this mechanism, optimal and fast charging becomes possible in response to battery performance and the usage environment.

I'd guess, though, that you'd have to pay to become a CHAdeMO member to find out the actual CAN-bus message formats

 

[UhClem]

I wonder if the CHAdeMO messages are on the OBD-II port too? If so, then you should be able to see the CHAdeMO messages on your ScanGauge

If not, I suppose you could get male and female CHAdeMO connectors and build an "extension cord" so you could snoop on CHAdeMO's private CAN-bus. :shock:

It looks like the CHAdeMO Association has "Observer" membership that doesn't have to pay dues:

Membership Dues Annual membership duties shall be ¥900,000 for Executive Members, ¥500,000 for Regular Members and ¥100,000 for Supporting Members; provided, however, that, among the Supporting Members, those corporations and bodies who provide charging services for the general public and Observers are exempt from payment of dues

Non-profit and other bodies approved by the Executive Board can join the Association as observers.

All we have to do is form a non-profit and get approved :lol:

 

[AndyH]

Spend $20 and download the service manuals. All the messages, error codes, and associated car-side systems and interconnects are fully documented.

There are some clues in the SAE J1772 quick charge efforts, as there are members of Nissan and TEPCO involved, and interoperability is part of the plan. Nissan's doing the communications packets for the SAE QC extension to J1772, for example.

To get more info (the rest of the story!), one would likely have to connect with TEPCO and/or another CHAdeMO member for the hows and whats. Here's a US contact: http://www.akerwade.com/v.php?pg=78

Good Hunting!
Andy

 

[JimK]

Thanks for the info! It's good that TEPCO and the other CHAdeMO members want to create a standard for rapid DC charging of EVs. However in my opinion, to create an international standard at a minimum the communication protocol needs to be open source. It is unfortunate that they are creating a monopoly for a few companies to provide quick charge stations (expected to be $100,000. each). I can understand patenting the technology for the charger to provide the DC current source to the EV, power factor correction techniques, etcetera. But again we hackers and entrepreneurs could undoubtedly come up with lower cost chargers that would let you select a rapid charge rate or a reduced rate for those of us that want to extend our battery life but don’t want to wait 6-8 hours. I can imagine my 40 amp 240 volt circuit providing 7680 watts of DC to my EV not just 3300 watts (2.5 to 3.5 hours for a full charge). I’ll keep looking for more info…

 

[garygid]

I agree, the QC control protocol details should be made public.

Perhaps, if it is included in the US J1772 QC "standard", the standards committee will "have to" publish the details, so that even small EV "makers" and converters will be able to design QC-compatible vehicles.

 

[JimK]

Now for a practical question; if someone made an adapter to go from the J1772 level 2 EVSE to the Leaf’s DC charge port how much would people pay for it?

Using a boost mode converter you should be able to get at least 6600 watts into the DC charging port. I have enough information about the level 2 EVSE protocol; I just need to get info on the CHAdeMO CAN buss commands to access how difficult it would be to design an adapter or a level 3 charger. Note: the AeroVironment EVSE-RS limits the current to 30 amps (7200 watts @ 240v) although the 40a service required could supply 32amps by code.

 

[EVDRIVER]

Now for a practical question; if someone made an adapter to go from the J1772 level 2 EVSE to the Leaf’s DC charge port how much would people pay for it?

Using a boost mode converter you should be able to get at least 6600 watts into the DC charging port. I have enough information about the level 2 EVSE protocol; I just need to get info on the CHAdeMO CAN buss commands to access how difficult it would be to design an adapter or a level 3 charger. Note: the AeroVironment EVSE-RS limits the current to 30 amps (7200 watts @ 240v) although the 40a service required could supply 32amps by code.

An adaptor with full control of course, one that will meet all the same parameters which is not tough since the current is low. I affordable option is a crude high-current charger like a bad boy that cuts of very early to get the bulk in. The J ends are very affordable without the cable, even the 80A version but I don't know about the other.

 

[JimK]

To build my own EVSE I purchased a 30 amp J1772 connector set with a 25’ cable from ITT-Cannon and even at OEM pricing they cost me ~ $260. If you have a source for lower cost connectors please let me know. Especially the TEPCO connectors! I can’t resist the temptation to tinker. Who knows maybe a group of us could start the non-profit mentioned earlier, join CHAdeMO and come up with a product???

 

[smkettner]

Now for a practical question; if someone made an adapter to go from the J1772 level 2 EVSE to the Leaf’s DC charge port how much would people pay for it?

Using a boost mode converter you should be able to get at least 6600 watts into the DC charging port. I have enough information about the level 2 EVSE protocol; I just need to get info on the CHAdeMO CAN buss commands to access how difficult it would be to design an adapter or a level 3 charger. Note: the AeroVironment EVSE-RS limits the current to 30 amps (7200 watts @ 240v) although the 40a service required could supply 32amps by code.

Why have the evse? Just plug your converter into a standard 50a outlet for 9,600+ watts. With short charge times you may not even need to meet the continuous load 80% of breaker rating.

 

[DarkStar]

Now for a practical question; if someone made an adapter to go from the J1772 level 2 EVSE to the Leaf’s DC charge port how much would people pay for it?

J1772 != CHAdeMO (DC charge port)

I'm confused by what you are offering. Are you suggesting developing a 6.6 KW charger that you can plug a J1772 EVSE into and that charger plugs into the CHAdeMO port?

The charger on the Nissan Leaf accepts AC voltage from a Level 2 EVSE, the CHAdeMO connector is for a DC voltage and adds CAN-bus communication to regulate the voltage and amperage provided on the port. The CHAdeMO connector goes directly to the battery pack, it doesn't go through the on-board charger. That's why you have a refrigerator-sized charging station at CHAdeMO stations.

The J1772-2010 standard could just state that Level 3 is the CHAdeMO standard without publishing that standard. It would continue to require companies to join the group (costing lost of money) in order to receive a copy of the standard to implement it.

 

[JimK]

My knowledge of Lithium manganese batteries is that they have a higher capacity than other lithium chemistries but have a lower ‘C’ value (near 1). So with a 25kWh Lithium manganese battery you probably shouldn’t charge it faster than 25kW (1 hour rate). Even then the higher rate should only be used until ~80% of charge. Most J1772 level 2 charge docks will have a minimum of 30 amps available with 70 amps being the upper limit. The Leaf has an on-board 3300 watt charger and can not utilize the full capacity of a J1772 EVSE. I am not proposing a refrigerator size 70kW 480v 3phase charger. I am thinking that an external charger could be made (toaster size) that could use any public or private J1772 as the power source and charge the Leaf at a 6600 watt or higher rate through the QC port. After all if the Leaf had a 6600 watt charger it would take the 240v AC power and convert it to a DC current source connected to the battery buss. Why not do that externally and feed the DC into the quick charge port? So if all else fails some of us hackers could use a male and female TEPCO connector to monitor the CAN communication, decode the protocol, and build an external charger that would let the user select the charge rate, up to the maximum allowed by the EVSE in use.

 

[Coffee_Slurry]

That's the proposal as I understood it:
Build an EXTERNAL charger that accepts J1772 as input power, and provides DC charging via CHAdeMO connector to the Leaf.

This way, you could at least have a 7kW charger at home. Maybe even heavy-lift portable.

I believe most public L2 facilities will be 6kW or better, not limited to 3.3kW. Since the charger in the car is whimpy, bring one that's larger.

I don't really see this taking off, but for someone with a real need for faster charging in one location, why not a small CHAdeMO home-use charger?

 

[tps]

I hope that Nissan will "fix" this problem in 2012 for those of us who have to wait a year anyway by just including a 6.6kW or even 7.2kW on-board charger. This would probably make more sense for destination charging than overnight charging at home. With destination charging, one wants to pump kWh into the battery as fast as practical, while with overnight charging at home, the 3.3kW charge rate will probably pump kWh into the battery fast enough to replace a day's worth of typical usage. I (and many others here) could probably get by fine with L1 overnight charging.

 

[garygid]

From a 50-amp 240v circuit (like at an RV park, one could pull 12 kW for an hour (or maybe 1 hour 36 minutes for an empty to 80% charge) and not be a continuous load.

Then, just make a L3 charger, AC to DC, regulation and current limiting, communication with the EV, and cooling.

Simple, right?

In a lunch pail or briefcase, for $1000, get UL approval and you would have a product.

Add an option for other plugs, and sockets, including J1772 inputs and outputs, and user settings, and you would have a L1/L2/L3 combo ...

Please let us know when it will be ready.

Of course, some of us have to get sonething else "soon", but hundreds of thousands of EVs will follow.

 

[webfootguy]

Interesting discussion. I've been collecting CHAdeMO info as I run across it on the web. There have been a few presentations that include some of the details. The doc "Safety Design of CHAdeMO Quick
Charger and its impact on Power Grid" from Dec 1, 2010 is a good overview and includes pictures of the actual hardware insides. Here is a pdf file that contains some info http://filesave.me/file/8417/takafumi-anegawa-tepco-11-20-1290790915-pdf.html

 

[EVDRIVER]

From a 50-amp 240v circuit (like at an RV park, one could pull 12 kW for an hour (or maybe 1 hour 36 minutes for an empty to 80% charge) and not be a continuous load.

Then, just make a L3 charger, AC to DC, regulation and current limiting, communication with the EV, and cooling.

Simple, right?

In a lunch pail or briefcase, for $1000, get UL approval and you would have a product.

Add an option for other plugs, and sockets, including J1772 inputs and outputs, and user settings, and you would have a L1/L2/L3 combo ...

Please let us know when it will be ready.

Of course, some of us have to get sonething else "soon", but hundreds of thousands of EVs will follow.

For approval the charger will need to be isolated, UL approval would likely exceed $100K on the unit.