15 November 2010

J1772 standard plug appears for sale on the internet

Those of us who could not renew our lease on the Mini E had the option of keeping the wall mounted EVSE, which is the safety and convenience interface box for charging.  But since it has a connector that is specific to the Mini E, it is of limited use.

Clipper Creek, the manufacturer of the EVSE (electric vehicle service equipment) supplied with the Mini E has not yet been able to supply an upgrade cord and connector to convert to the new standard connector, called the SAE J1772 connector.  This will be used by the Nissan Leaf, Chevy Volt, and other upcoming electric cars for sale in the US market.

Before giving the links to the connectors for sale on the Internet, allow me to speculate as to why UL is giving Clipper Creek a hard time about upgrading existing 240 volt EVSE boxes to J1772.

One of the UL requirements met by the Clipper Creek wall box appears to be that it is explosion proof, like all electrical equipment that might be installed at a gasoline filling station is required to be.  This means that the enclosure is sealed and air tight.  If the cable were changed and the new cable were not exactly the same diameter, it might not meet these requirements.

Even in your garage, this might be important.  Building and electrical codes usually require that all possible sources of ignition in a garage such as electrical outlets (which can cause sparks), switches, water heaters with an open flame, etc., must all be installed at least 18 inches above the floor, where gasoline fumes collect.  Your car does not emit gas fumes, you say?  Not today.  Maybe tomorrow.  Stuff breaks.  It is better if your house does not explode just because a hose clamp splits in your car.

The kind of spark that can be created from a 240 volt 50 amp breaker in an EVSE it much more intense than what you get from a light switch.  Better to keep it sealed in an air tight box, don't you think?  Not to mention that UL requires these EVSE to be safe around cars powered by lead acid batteries that can emit lots of hydrogen gas.  (If you have one of those, code requires that the EVSE starts a ventilation fan before charging in an enclosed space.  The Clipper Creek EVSE can provide for that too.)

So anyone who is considering converting the connector on your Clipper Creek box, please keep the safety points above in mind.  If you think it cannot happen to you, try typing "house explosion" into Google news.

And of course, the current rating on the new cable must equal or exceed the rating of your EVSE.  Don't go putting a 32 amp cable on a 50 amp Clipper Creek box.

Now, here is what I found for sale today:

70 amp connector and socket, 40 foot cable, $475 from Current EV Tech
The picture at the top of this post came from the above link.  The blog where I originally found this catalog said that Current EV Tech once offered a UL certified J1772 plug from ITT Cannon for over $800.  I don't know if this link is also from ITT cannon, which is a very reputable name in connectors.

32 amp plug only, $450
Not much info on this page, it lists a part number that appears to be of Chinese origin. It might be the same as the one above for all I can tell, but no mention is made of a cable that I can find today.

Like all things electronic, I expect the prices to drop and UL certification to be more common.  Just watch out for the seal going into the EVSE box, try to keep it air tight.

13 November 2010

Charging safety

I recently posted some photos of the last long trip we took in the Mini E before we had to return the electric car. This 1000 mile round trip involved charging the car at RV campgrounds. This is technically not allowed by the National Electrical Code, which allows an RV to connect to a 50 amp 240 outlet but does not allow electric cars to charge from them. I generally agree with this regulation, as I am an electrical engineer who is quite concerned with safety.  The old connector design is not particularly safe for frequent use, especially outdoors. RVs are "grandfathered" in, but newer safer connection technology should be required for electric car charging.

Shortly after I posted these photos, Mini emailed a reminder all the lessees that this sort of connection is actually forbidden by the terms of the lease. They said in part "...It is crucial to the safe operation of the vehicle that any equipment not supplied by MINI, never be used to charge or operate your MINI E. This includes any electrical connection adapter for the vehicle, OUC, or wallbox, and also prohibits the use of the OUC or the wallbox in any location not specifically intended for its designed or installed use."

I would not recommend that anyone else do what I did. And I should mention that with one exception, either myself or my wife (who is also an engineer) was constantly monitoring the charging connection and process on this trip. Part of the motivation for trying this was to see if cross country travel could be at all practical in a production electric car. The idea was not to repeatedly take long trips with a research vehicle like the Mini E. My conclusion is that cross country travel is just barely practical if the electric car has AT LEAST a 50 amp BUILT IN charging ability. Note that NONE of the several electric cars soon to come to market offers this. The only exception is the Tesla, which offers up to 80 amps as I understand it. But 80 amps can only be supplied from dedicated EV connections, since the largest commonly available general purpose outlet in the US is 50 amps.

I understand that Tesla has figured out a way to allow their customers to safely charge from the connections available at RV campgrounds, the so called NEMA 14-50 outlets which are also commonly used for electric stoves in the US. But Telsa sells their cars, so they can afford to develop a small travel version of the safety and convenience interface, the so called EVSE box (Electric Vehicle Service Equipment) like our larger Clipper Creek box. BMW is only leasing the Mini E as part of a research project, and we should all respect the constraints this places on what is offered.

But an even larger motivation of posting what we did on our long trip was aimed at the Mini E drivers out there that are doing even riskier things. I wanted to show that you CAN use the Clipper Creek safety interface.  NO ONE should be charging their car without taking advantage of the numerous safety features offered by the Electric Vehicle Service Equipment box, even if you are traveling. Yes, it is big but there is that roof rack available from Mini that I showed in all the photos, without saying one word about it until now. Hint hint!

From the way the news is coming in, this will all be moot soon enough when fast chargers are available in more places. But that will take time. Meanwhile, there will always be people pushing the envelope. The real point of my posting was this: If you are going to break the rules, DON'T CHARGE WITHOUT THE EVSE! ALWAYS USE A SAFETY BOX! Really, Mini is right, please don't break any of the rules. But for those out there who are going to break some anyway, be aware of what is a "mortal sin" and what is a "venial sin", so to say.

And especially, do not ever run 30 amps through the small yellow "occasional use cord". I know there are some who have tried this, but there is a large risk of fire. 12 amps max for the little yellow EVSE!