Inside the EVSE

This is my first post so please direct me genteelly if I have broken any rules.

I just installed a 40 amp service in my garage in anticipation of installing an EVSE. Rooting around the Internet, I found some information about what is contained in the EVSE: a J1772 cord and line, a container box, a DPDT relay, a 12Vdc signal voltage, various led indicators, a logic unit and a 1K resistor. I believe that's all...if there is more, please let me know.

Additionally, I believe the logic from the Leaf charger drives the EVSE with a series of voltages that work in conjunction with the resistor and 12vdc signal through the use of a voltage divider in the car: at 12volts the EVSE relays are open and no AC flows, at below 6volts, the relays close and AC flows to the charger; when the charger has finished its work, it produces a 9volt signal that opens the relay.

So it looks like the EVSE has a logic circuit to control the relay, driven by voltages from the Leaf's charger.

Question: Does anyone have a schematic and/or a parts list of an EVSEor knows where to find them?

fotajoye said:

This is my first post so please direct me genteelly if I have broken any rules.

I just installed a 40 amp service in my garage in anticipation of installing an EVSE. Rooting around the Internet, I found some information about what is contained in the EVSE: a J1772 cord and line, a container box, a DPDT relay, a 12Vdc signal voltage, various led indicators, a logic unit and a 1K resistor. I believe that's all...if there is more, please let me know.

Additionally, I believe the logic from the Leaf charger drives the EVSE with a series of voltages that work in conjunction with the resistor and 12vdc signal through the use of a voltage divider in the car: at 12volts the EVSE relays are open and no AC flows, at below 6volts, the relays close and AC flows to the charger; when the charger has finished its work, it produces a 9volt signal that opens the relay.

So it looks like the EVSE has a logic circuit to control the relay, driven by voltages from the Leaf's charger.

Question: Does anyone have a schematic and/or a parts list of an EVSEor knows where to find them?

Click to expand...

It sounds to me like you're thinking of building your own EVSE? That's a mighty big gamble with the voltages involved and the price of the car on the line should something not work as planned...... :?

fotajoye said:

Question: Does anyone have a schematic and/or a parts list of an EVSEor knows where to find them?

Click to expand...

There are no "open source" schematics for J1772 compliant EVSEs, but you should be able to find all you need to know about them on the wikipedia page: http://en.wikipedia.org/wiki/SAE_J1772

Edit: Funny - first google search for "j1772 schematic" links to this thread which already covers this topic.

http://www.mynissanleaf.com/viewtopic.php?f=4&t=683

Please search before starting new threads!

Look at our "Build your own EVSE ..." topic.
It links to a web site where a DIY project is making good headway.

However, soon properly designed, UL listed EVSEs will be available from a couple of sources at "reasonable" (and decreasing) prices.

There is the GFI function, control buttons, a durable housing, EM noise suppression, and the cord strain-relief that you did not mention.

The Nissan-supplied units and cords are weather resistant, and they should take being driven over without significant damage or safety risks. Just making something "that works" is not difficult.

fotajoye said:

Question: Does anyone have a schematic and/or a parts list of an EVSEor knows where to find them?

Click to expand...

A few of us are currently working on this. I would watch the Modular EV Power website for more developments!

Thank you for the information and the block diagram schmatic is helpful to understand the logic of the EVSE. I looked at the suggested thread and found that it appeared to be going in a direct somewhat off the subject.

I did uncover some additional data that might be of value if there are others interested in knowing the circuits, logic and "handshaking" between the EVSE and an EV charger. see:

http://jackrickard.blogspot.com/

DarkStar said:

fotajoye said:

Question: Does anyone have a schematic and/or a parts list of an EVSEor knows where to find them?

Click to expand...

A few of us are currently working on this. I would watch the Modular EV Power website for more developments!

Click to expand...

Why exactly? Many of the products are way over priced and making an EVSE is not financially practical.

Welcome fotajoye -

If you have the patience to root around the forum enough, there is a thread on the AV EVSE with a lot of good quality pix posted. You might get some ideas from looking at those pix.

Why make something instead of just buying it off-the-shelf? I've always assembled kits whenever I could (have more stuff from Ramsey Electronics than I would care to admit and I'm too young to have much Heathkit stuff) because most kit manufacturers walk you through the process in a way that helps you learn how the components function.

Now I find myself, instead of throwing away a video card for example, going over to Mouser Electronics, buying the replacement capacitors, soldering them in and having a perfectly functioning video card. Sure I just spent $10 on a $45 card, but I'll take that extra $35 any day of the week!

"Makers" and "Crafters" are trending to be more-and-more popular, not only for hobbies, but because they gain additional value from doing something with their own two hands. Check out Make:Magazine, Nuts & Volts, or any of those hobby electronics magazines and I'm sure you'll find something fun.

In the end, it really isn't so much about the cost, but about gaining knowledge and experience we otherwise wouldn't be able to have. Specifically, what Modular EV Power is doing will allow us to eventually have a jump-start for once these EVSEs need servicing and maintenance. Sure costs will go down, but as companies start throwing away these "first-generation" units, I want to be prepared to be able to refurbish them for little cost and place them back into service.

Viva the EV revolution!

Right on! I'm one of those old guys that refuses to live in the past and talk about what use to be. My other car is a Datsun 240z turbo race car that I road race.

I'm not into designing circuits any longer, can't find the time; but, I see this excellent group of EV believers as a source of technical information to help owners fix and mod their BEVs, not for the race track but for the street. Additionally, just learning the design is somewhat of a kick.

Have a black SV ordered...4/11 delivery.

It sounds like you're thinking of building your own, and I think you're description of the voltage signals is correct. Awesome. Please post the schematics and build pics when you're done. Please let us know about your sources for the cables and plugs too.

Having looked at the guts of a number of these things (online, not in person unfortunately), it seems most of the electronics is for secondary purposes (lighting LEDs, wireless, etc.).

Good luck!

It appears that more and more information is being discovered about the logic and circuitry of the J1772 2010 standard.

As many know there is a member who now offers to upgrade the Nissan "emergency" factory L1 charger so it will also operate on an input from 240 volts AC. The advantages are: it's portable and will charge the batteries at 2.8 kw instead of 1.6kw. As you know the L2 chargers charge at 3.2kw. so this modification alone at $225 allows you to select either 120 volts or 240 volts and is not far from a fully-blown L2 charger; the difference is about 400 watts.

see: Post subject: Re: Nissan L1 EVSE third-party upgrade to both 120V and 240V at this forum.

The above numbers are slightly off:
120 x 12 = 1.44 kW
240 x 12 = 2.88 kW, a 1440 watt improvement
240 x 16 = 3.84 kW, a 960 watt difference

Thank you for the corrections; appreciate it!

I learned yesterday that someone is making a module for the J1772 garage version that will take care of the pilot control of the device and I will be looking for that on the internet;

If Nissan offers an upgraded charger to the gen one Leaf, one may want to look ahead to make sure the EVSE they buy is not limited to 16 amps.

I have information on a module that takes care of the communications between the EVSE and the car; but, can't find out how much it is selling for; The module is a Mennekes CP Communications box 30511-AA. I think it's German.
If anyone has info on this, please let me know.

Since this thread is quite similar, I would like to direct the members to a more active thread on the same subject:
http://www.mynissanleaf.com/viewtopic.php?f=26&t=2736