Don
Site Moderator
Posts: 2432
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Open EVSE

Wed Sep 05, 2012 6:50 pm

Chris Howell has been working on an open source code EVSE for a couple years now. Each revision of it he develops is a more refined, more professional, easier to build and use product than the last one. You can read the history of it at this thread on the Leaf forum

http://www.mynissanleaf.com/viewtopic.php?f=26&t=6546

It's nearly 50 pages of posts, but if the topic intrests you at all, the history of how it all came to be is pretty interesting . . . . or at least it was to me

Chris maintains a website with all the latest information, revisions, downloads, links to sources for parts and all here

http://code.google.com/p/open-evse/

I decided to build me one and began collecting the parts about 3 months ago. I posted here about my charge handle with the built in LED light viewtopic.php?f=7&t=425&hilit=LED&start=10

Since these are mostly 'home made' they come in all shapes and sizes - You can build them with or without the LCD readout and you can make them fixed or portable, depending on what type of enclosure you build it in. I chose a small Pelican case for mine, because it's easy to open and I wanted to mount it on a wall. Many others use smaller, more rugged enclosures and use them as portable units. My portable unit is my EVSE Upgraded OEM Mitsu Panasonic unit which charges at 12 amps on both 120 and 240 volts

Here's the completed unit in the case
Image

A view with the door open
Image

Back view showing more of the components
Image

Plugged in, ready to charge - The blue ring is the illuminated switch which selects charge current, etc
Image

Charging the car
Image

This unit is using the latest release firmware which gives you adjustable charge current. On L1 it will charge at 6, 8, 10, 12, 14, 15, or 16 amps. On L2 it can be adjusted to 6, 8, 10, 12, 14, 16 or 20 amps. Mine is using 20 amp fuses, so it probably won't do 20 amps without changing those - The iMiEV doesn't need 16 or 20 amps anyway

It also has Auto Detect of L1/L2, GFCI protection, a ground check, a diode check, a vent required check, and stuck relay protection - It's actually much more J1772 compliant than the factory EVSE

Depending on what parts you buy and where you source them, it's about a $350 project, give or take. I didn't want a long pigtail, so rather than spend a fortune on one and end up cutting it in half, I bought 10 feet of 7 conductor 16 gauge wire and used two strands for each charge conductor. That left one for ground, one for the pilot signal and I used the 7th one to power my charge handle LED from the unit's 5 VDC supply

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1994 Miata 60K miles - Soon to be sold
1979 Honda CBX six into six

MLucas
Posts: 833
Joined: Thu Jun 07, 2012 8:52 am
Location: Niagara on the Lake, Ontario, Canada

Re: Open EVSE

Thu Sep 06, 2012 6:33 am

I saw this and really wanted to build it. If I had more time, I would have definitely gone this route instead of buying the $800 dollar Square D Level 2 EVSE. I think the total price is about $650, so we still save a lot going this route and the builder gets to customize it the way they like.

I noted Chris had stopped accepting orders for the kit at the time I decided to buy the car to catch up on backorders. Between buying the car and having to drive it to work in a week, I just couldn't come up with the time to make this happen.

On a side note, at the low volume pricing of $650 you can see how we are getting ripped off buying the off the shelf EVSEs. With those companies buying power, the parts for them have to cost even less. The Square D is about as basic as you can get, a box, a PCB to sense the +9V pilot signal + GFCI, a big fuse and a relay. That is all that is inside of them things. The Square D doesn't even come with any monitoring capability like this one does.
Last edited by MLucas on Thu Sep 06, 2012 9:17 am, edited 1 time in total.

Like Dylan...I went electric.

  • Purchased: June 29th, 2012
  • Mileage on June 29th, 2013 - 25,431 km / 15,802 miles
  • Mileage on June 29th, 2014 - 51,286 km / 32,616 miles

List of Oil Spills: http://en.wikipedia.org/wiki/List_of_oil_spills

Don
Site Moderator
Posts: 2432
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Open EVSE

Thu Sep 06, 2012 8:22 am

My build was less than $400 and if you opted not to have the display, it could be done for even less than that

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1994 Miata 60K miles - Soon to be sold
1979 Honda CBX six into six

MLucas
Posts: 833
Joined: Thu Jun 07, 2012 8:52 am
Location: Niagara on the Lake, Ontario, Canada

Re: Open EVSE

Thu Sep 06, 2012 9:19 am

Don wrote:My build was less than $400 and if you opted not to have the display, it could be done for even less than that.


What a deal! I forgot about opting out of the display, right - you don't really need that at all if you plan to monitor this from your computer or smartphone.

Like Dylan...I went electric.

  • Purchased: June 29th, 2012
  • Mileage on June 29th, 2013 - 25,431 km / 15,802 miles
  • Mileage on June 29th, 2014 - 51,286 km / 32,616 miles

List of Oil Spills: http://en.wikipedia.org/wiki/List_of_oil_spills

evcar
Posts: 27
Joined: Sat Aug 25, 2012 3:40 am

Re: Open EVSE

Thu Sep 06, 2012 1:02 pm

Chris told me I'm on waiting list - I have placed order about week ago...?
As I'm in Poland I like to have one - and I will try to build more by my friend-electrician....
Really excited to have it :)

Don
Site Moderator
Posts: 2432
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Open EVSE

Thu Sep 06, 2012 1:49 pm

MLucas wrote:What a deal! I forgot about opting out of the display, right - you don't really need that at all if you plan to monitor this from your computer or smartphone
It has no provisions for monitoring with a smartphone or anything else. Without the display, it's much like the OEM EVSE after it's been upgraded by EVSE Upgrade.com - A fixed charge current for L1 and L2 and automatic switching between the two. The display and the front panel switch on mine allows the user to select whatever charge current they want for L1 and they can select a different charge current for L2. The unit automatically switches between L1 and L2 when you plug it into either 120 or 240 volts

Commercially made EVSE's must meet all sorts of codes and homebuilt units don't meet any of those, so it's natural I suppose that the cost is higher for the commercially produced units

It's really nice that Chris and the others at Open EVSE provide all the information that they do in the public domain for those of us who would like to do our own thing - I don't know of any other way you could get a unit as versatile as this one except to build it yourself - It's a rewarding project, but probably not something for those who have no electronics background at all and/or those who have never used a soldering iron to build anything. It's not an especially difficult job for someone with the appropriate background, but it's not something everyone could do

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1994 Miata 60K miles - Soon to be sold
1979 Honda CBX six into six

MLucas
Posts: 833
Joined: Thu Jun 07, 2012 8:52 am
Location: Niagara on the Lake, Ontario, Canada

Re: Open EVSE

Fri Sep 07, 2012 6:40 am

You are right again, Don. I was thinking of the Open Home Energy Monitor project. But, I'm sure with a little bit of ingenuity and few more parts this can be made to be read by a remote server serving up a web page which then would be accessible by any web enabled device.

I've been looking at the arduino projects and going to delve more into this field. I've read over on the Leaf forum Lincomatic has built an SOC gauge for the ODB port. They've figured out the wiring and the codes, looks really nice and gives more information than our instruments give us.

http://blog.lincomatic.com/?p=639

Like Dylan...I went electric.

  • Purchased: June 29th, 2012
  • Mileage on June 29th, 2013 - 25,431 km / 15,802 miles
  • Mileage on June 29th, 2014 - 51,286 km / 32,616 miles

List of Oil Spills: http://en.wikipedia.org/wiki/List_of_oil_spills

Don
Site Moderator
Posts: 2432
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Open EVSE

Fri Sep 07, 2012 8:52 am

Yes, they're headed into projects that can be monitored/controlled using cel phones and iPads and it won't be long before you can build something along those lines in your personal workshop . . . . or at the kitchen table in my case :D Pretty soon they'll have an EVSE that looks like a laptop power supply and is controlled by your laptop as well - Start, stop at any time and charge using whatever amp or kwh rate you like, with the results showing up in a spreadsheet

BTW - Lincomatic wrote much of the code that the version I built runs on. As I understand it, he's a real programming wizard and Chris is an expert at redesigning circuit boards and shrinking them to their minimum size - A great combination

There are so many more Leaf owners than we have at this point - Hopefully we'll one day have some talented engineers playing around with the software/hardware this car runs on and we'll have lots more options to make modifications and improvements

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1994 Miata 60K miles - Soon to be sold
1979 Honda CBX six into six

PV1
Site Moderator
Posts: 2845
Joined: Fri Apr 27, 2012 4:22 pm
Location: Pittsburgh, PA
Contact: Website

Re: Open EVSE

Thu Sep 27, 2012 7:16 pm

Quick question, the OP says that the open EVSE can handle 16 amps at 120 VAC. Will the i charge at 16 amps at level 1, and if not, what is the max amperage (or wattage) of the onboard charger at 120 VAC?
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

Don
Site Moderator
Posts: 2432
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Open EVSE

Fri Sep 28, 2012 4:11 pm

I looked high and low for some spec on what the car's charger is rated for L1 charging - Couldn't find a thing

I set my Open EVSE for L1, 16 amps, plugged it into my wattmeter and began charging the car. The wattmeter reads 1725 watts, 14.6 amps @ 118 volts. Don't know for sure, but I would guess this is the designed maximum for the charger when used on L1

Hope this helps,

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1994 Miata 60K miles - Soon to be sold
1979 Honda CBX six into six

Return to “EVSE (Charging Stations)”