Are you interested in building your own charging cable?

Does it tell you total kWh so far? (Since frequency/voltage can vary, its not just the max rated). Does it tell you what actuall charging is used if the car negociates a lower level?

What is the lowest Amp rating it can negociate? I'm thinking of having some students extend it to have multiple chargers on one circuit (too expensive for them to pull a new line to the garage, but maybe 2-3 cars could share the load by accepting a lower amp charging level).

 

It does none of that now, Chris is working on that, if you read the threads over on the MNL forum.
It's all possible, its mostly software. The EVSE tells the vehicle what current is availble, not the other way around. the car cannot negotiate a lower current, but must conform to the current the EVSE tells it is availble via the pilot signal.

 

Chris just released code that uses 1 button to adjust current, but it isn't working with the AdaFruit RGB LCD display yet, that code is not done yet. The button used is a discreet button on another input to the processor. It will take some more time for the AdaFruit support to get done...

 

Well, I finally found the time to put together my Open EVSE. It seems to be charging fine (blue light) on 220V. Total cost $462.
Thank you terrylowe for the clear example, chris1howell for the open evse and power supply, modular ev power for the J1772 cable and mitch672 for your insight.

 

well done!

 

Looks good LurkAzusa, what I did differently is used an L6-30P plug (240V / 30A), and then built adapters to a standard 120V plug, and to other 240V outlets. I also used the AdaFruit RGB LCD display, but thats mostly informational now, and isn't needed.

 

I was going to do that, but decided that in the near future it will be my home unit on 20A 220V. I did build a 20A to 15A adapter. If I need 30A in the future, I will just need to replace the plug, as the EVSE is built for 30A, but the garage main lug isn't at this time.

 

Well, thanks to Mitch's comments I have decided to build my own EVSE. I emailed Chris this morning and asked to be put on the wait list. I was going to send mine to EVSEupgrade.com but with the new, cheaper j1772 plugs out there it wont cost much more to have a second unit.

I want to make a few of them actually. I am going to install them at my rental properties as a perk for tenants and so I can charge while I am working. I was originally worried about the potential liability of a home made EVSE torching someones car but I really dont think that would happen. So, Im going to go for it.

Question;
Has anyone made a double unit before? I assume I would need two of everything to get the job done. I only have 50 amp service in the garage so I would probably limit each EVSE to 16 amps.

THANKS TO ALL THE PIONEERS WHO HAVE MADE THIS POSSIBLE!!!!

 

There is a $125 bargain on ebay at the moment, trade show demo unit....

SAE J1772 UL Listed 40 Amp EVSE Connector & 15 Foot Cable | eBay

 

You can buy a 25' 30A cable directly from Leviton for $126 + shipping:
Level 2, 30A, J1772 Compliant Electric Vehicle Charge Connector with 25' EV rated Charge Cord Only, A3435-PEV : J1772 Charge Connector and Cable

I also have my portable 30A OpenEVSE still availbe for $550, and a Leviton EV2430WS available for $650

 

I just noticed that your ground fault coil is on the J1772 side of your relay rather than the supply side of the fuses. Was that intentional?

 

Yes, according to the

Open EVSE/EVSEwAdvanced_Power_supply.sch document dated 3/27/12

 

If you look at my OpenEVSE build, you will see the same thing:
EVSE_by_mwolrich - open-evse - A portable EVSE built with an Open EVSE board. - Open Electric Vehicle Supply Equipment (EVSE) - Google Project Hosting
The monitoring is for a ground fault on the vehicle side, which is the reason to monitor the J-1772 cable.

 

If it is residential, the 4 wire plug is probably 4 wire, ~240V, single phase. L1, l2, Neutral and Earth. The neutral allows a connected machine to obtain 120Vac from L1 or L2 to neutral to operate lower voltage circuits within the connected machine.

 

Yes, if you get an OpenEVSE with the "Advanced Power Supply" (which is the surface mount board Chris Howell has, along with his Advanced Power supply that "sandwiches" with the OpenEVSE PCB), or you get the "DIY V4.0" PCB and build it up, they both have support for connecting the L1/L2 lines, and do detect Level 1 or Level 2 properly, it also has separate amperage settings for L1/L2, so you can set them independently.

BTW, I just built a 75A high power version, for my Tesla Model S thats on order, see this link:
75AOpenEVSE - open-evse - A 75A EVSE built with an Open EVSE board. - Open Electric Vehicle Supply Equipment (EVSE) - Google Project Hosting

Leviton now has the 75A cable for a fantastic price, $218.69:
75 Amp J1772 Level 2 Electric Vehicle Charge Connector with 25 Ft. Cord, A2055-PEV : J1772 Charge Connector and Cable

It wasn't availble when I built mine, or I would not have needed to use the 4' of liquidtight and fittings I had to, to get a few extra feet on the 20' ITT 75A cable I bought (the Leviton is 25')

 

I sold the 30A portable OpenEVSE, and the Schnieder EV2430WS already...

I could possibly put together one of the OpenEVSE V4.0 boards for you, but it's likely I'd have to order (3) PCBs from OshPark, that's their minimum order, unless Greg has 1 left. 3 of them would cost around $45, and take about 2 weeks to get, the DigiKey parts, are probably another $60 or so, then you need a 12V power supply as well (between $16 and $28 depending on where you buy it).
In other words, it's no less expensive than getting it from Chris, might be a week faster, but I would have to solder it together, program the Atmel328P (which I now know how to do from a brand new chip), and then test it on the AdaFruit RGB LCD display.

I could put it all together for you, power supply, OpenEVSE V4.0, AdaFruit RGB LCD display, even the 12V 30A DPDT relay, even the GFCI CT, you would just have to mount it all in an enclosure/wire up the AC input/output (J-1772) and fuses, buy the J-1772 cable etc.

If your interested, let me know, I'll see if I can come up with a number