OpenEVSE - Open Source Charging Station

[GlennD]

It turns out that the ISP connector on the new boards is too close to the +- 12V module and a normal programming cable will not fit. Sorry, I am not able to help.

 

[GlennD]

I would like to know the procedure for programming an OpenEVSE with a FTDI port. I have always used the ISP port but I could not get a connector on the port of Chris's latest. The EVSE page says it can be programmed by ISP or FTDI.

 

[goldserve]

I would like to share some OpenEVSE build pictures: http://sdrv.ms/VIONyj" onclick="window.open(this.href);return false;

Any comments welcomed!

 

[GlennD]

In general your EVSE looks very good but you should clean up your display with isopropal alcohol. At least you did not use the intermittent in the making power poles.

 

[garygid]

After our next Gathering in Cerritos, the SoCal LEAF owners group
will be having a finish-building, testing, and re-programming
workshop, at the same place near the Mitsubishi Headquarters.

Try to have your RGB LCD display unit assembled before that time.

We are building our projects with the OpenEVSE Plus board.

 

[mitch672]

Ben (Cinergi) from the TMC forum was nice enough to drive his Tesla Model S over this afternoon, where it was tested on my 75A OpenEVSE. No issues, no noticable heating of the ITT J-1772 cable head either, it was running at 74A as shown on the Model S display.

TMC forum Post: http://www.teslamotorsclub.com/showthread.php/11953-75A-OpenEVSE-Testing-with-the-Tesla-Model-S-w-twin-chargers?p=233432#post233432" onclick="window.open(this.href);return false;

Direct link to the photobucket album: http://s461.photobucket.com/albums/qq333/mitch672/75A%20OpenEVSE%20Testing%20w-Tesla%20Model%20S/" onclick="window.open(this.href);return false;

Mitch

 

[fotajoye]

it was running at 74A as shown on the Model S display.

That is an excellent result and the owner is to be commended for offering his car for the test.
He must have been excited when you turned on the switch and the current first flowed to his $100,000 car,(ha)

 

[mitch672]

it was running at 74A as shown on the Model S display.

That is an excellent result and the owner is to be commended for offering his car for the test.
He must have been excited when you turned on the switch and the current first flowed to his $100,000 car,(ha)

Well, its not like this is the first car the OpenEVSE has been connected to, its been charging my Plug in Prius for several months. It is the first time its delivered more than 12A though. If you look at the pictures, you will see the voltage drops to 220 volts when the car is drawing 74Amps. I will have my utility check my drop wire/connections and the transformer supplying my house... its also on a very long overhead cable from the street, it might need to be upsized (if I whine enough, but its difficult to get utilities to do anything).

Ben has tested his car on the Tesla HPCs (used with the Roadster), he has the Roadster to Model S adapter cable (which costs as much as the 75A OpenEVSE I built, $600 for the cable, yikes)

So, its not the first time he's charged the car at over 40A, but it is the first time that a 75A J-1772 OpenEVSE has been used to charge a Model S, that we know of.

BTW, Tesla has a new J-1772 adapter, they swapped his out, the new ones plug into the J-1772 connector very easily (the old ones required a lot of force). I'm going to try to get an extra adapter from them, depending on the cost, then just leave it on my OpenEVSE (once the Model S arrives, that is)

in the meantime, I'll give my utility a call and see what they can do about that voltage drop.
BTW, you should have seen the meter spinning, 16.3KW was being drawn...

 

[fotajoye]

you should have seen the meter spinning, 16.3KW was being drawn...

I think I read that if you have the fast AC charge option, which it appears the car does, there are two 10 kw chargers ganged together for a total capability of 20 kw, that's a lota amperes. Don't know if you have been "reading the mail" but we have discussed weight in EVs...any idea what the Tesla chargers weight?

 

[mitch672]

No idea on the weight of the internal chargers, but each one is capable of pulling 10KW (40A @ 250V), they are designed to "work together" (Tandem), and in fact, that is how the Tesla SuperCharger works (it actually contains 12 of the same 10KW chargers the Model S uses, they are switched on and off in groups of 3 (because they are fed with 3 phase power, to 30KW, 60KW, 90KW or 120KW direct to the pack, 120Kw is not used yet, it shows as "225A at 400V" on the Model S during a SuperCharger session))

Not sure if each onboard charger weighs #50 or #100 it will make much of a difference to the 85KW Tesla Model S "miles/KW", it weighs in at a whopping #4600 pounds.

The beauty of the Model S is, you can charge from whatever you have availble, from a 120V 5A circuit (it can't be dialed down to less than 5A), to an 80A 240V Wall Mounted High Power charger, or a 75A J-1772 OpenEVSE. The only difference is how many miles per hour of charge you gain...

 

[DaveEV]

you will see the voltage drops to 220 volts when the car is drawing 74Amps.

That is quite a bit of voltage drop - did you confirm the voltage readings at other locations?

If the voltage dropped that much throughout the house (assuming you had 240V nominal), you'd see a good amount of light dimming when pulling that much current...

It also means that about 1500 W is being converted to heat somewhere along the line - not good!

 

[mitch672]

Yes, I will need to check it, unfortunately there won't be another load that large until my Model S arrives in February/March. It's based on the voltage display on the Model S itself, when the charging current was turned down to 5A, the car displayed 238 Volts. I have a very long overhead service drop, and an unknown distance to the transformer, more testing will be needed when the car arrives.. Luckily I will very rarely need to charge at that high a rate, it's just nice to have the capability to do so.

 

[dzd]

Just finished reading the Whole 74 page thread and catching up on what looks like a year or more of development. As a new Leaf owner, at least in 5 hours from now, Im real excited to get started with an Open EVSE!

Im curious, are there any builders in the Seattle area that might want to meet up? I wouldnt mind seeing some Open EVSEs in person and pick some brains.

I only hope that when Chris Adds me to the Waitlist for the PLUS board that im not too far down the list.

Cheers!!

 

[QueenBee]

Im curious, are there any builders in the Seattle area that might want to meet up? I wouldnt mind seeing some Open EVSEs in person and pick some brains.

I only hope that when Chris Adds me to the Waitlist for the PLUS board that im not too far down the list.

dzd: I'm in the area and am patiently waiting for of the boards to be completed. Haven't built one before and not sure how many others in the area would be interested but there have been local groups who built Gary's GID meter. FYI: THere is an active facebook group: https://www.facebook.com/groups/seattlenissanleaf/" onclick="window.open(this.href);return false;

Congrats on the new LEAF!

 

[garygid]

There is a Seattle group in our own Regional Discussions:
http://www.mynissanleaf.com/viewtopic.php?f=51&t=620" onclick="window.open(this.href);return false;

However, it is a bit long, it seems reasonably active.

 

[Ingineer]

you will see the voltage drops to 220 volts when the car is drawing 74Amps.

That is quite a bit of voltage drop - did you confirm the voltage readings at other locations?

If the voltage dropped that much throughout the house (assuming you had 240V nominal), you'd see a good amount of light dimming when pulling that much current...

It also means that about 1500 W is being converted to heat somewhere along the line - not good!

I would say this isn't unusual. 74A is a large load! Most all service drops are made of Aluminum as well, so they contribute a lot to the loss.

Keep in mind 20 volts is only 8.3%, and the specification allows for +/-10%.

-Phil

 

[garygid]

It is still good to check out where the loss is occurring,
to make sure that the loss (and heat) is not inside the
house, but just in the wiring leading to the house.

So, measure the voltage at the input to your breaker box.
If that drops to 220 volts, your wiring and connections
would seem to be good.

However, if all or most of the loss is between the service
inlet and your car, it would be best to investigate where
the heat is going.

 

[fotajoye]

It is still good to check out where the loss is occurring,
to make sure that the loss (and heat) is not inside the
house, but just in the wiring leading to the house.

Over the 40 years we have lived in my house we have lost service twice at the masthead where the drip loop is connected to the pole wiring...because of corrosive resistance and heat at the connection.

 

[aatheus]

All,

I wonder if you folks can possibly shed some light on weirdness that I am seeing with my OpenEVSE build. I got the Arduino Shield version of the OpenEVSE kit about a month back. Built it on an Arduino Uno, added the Adafruit display, running off a 90-250v 12v power supply (no Advanced Power Supply board). It was working great on 240v! I took it in to work to show off to some other EV owners, but they only have 120v outlets available. No problem, I thought. I made a 120v to L6-20 adapter cable and plugged in the OpenEVSE.

The OpenEVSE boards powered up fine and car started charging right away. For about 7 seconds. The car stopped charging like the cable had been unplugged. I tried charging on 240v when I got home. Same behavior. Car charges fine for 7 seconds, then stops. I tried turning the car on and the EV System Warning light came on! Fortunately the light cleared after a poweroff/poweron, and the car still charges normally on my Leviton EVSE.

I did some more experimenting. I was using version 0.5.0 of the firmware at the time, so I accidentally connected the OpenEVSE to 120v with the pilot set to 16A. This wasn't a problem, as work has 20A 120v sockets. Still, I upgraded the firmware to 1.0.0 and tried testing both L1 and L2 service levels. Same result

I enabled serial debugging on the OpenEVSE. The Pilot voltage drops to 8.6 when the car starts charging. After 7 seconds, the pin voltage drops to 2.6v and charging stops. This behavior is the same on 120v or 240v. Is it possible that I damaged the Pilot portion of the OpenEVSE shield?!

Very concerned, and annoyed with myself. It was working fine on 240!

 

[garygid]

Sounds like the EVSE is not producing the 1000 Hz square wave that
the car most likely wants to see.

Is the relay in the EVSE closing, to supply power to the car?

Perhaps your 12v power supply is damaged?