# $100 Open-Source Arduino-based EVSE



## valerun (Nov 12, 2010)

Hi All - 

We (http://www.eMotorWerks.com) are about to launch a new open source product - Arduino-based EVSE starting at $100 kit price (cheating a little bit as you would have to provide the cable - for example, from a 110V charging cord your Leaf is coming with...)

Can go up to 240V 60A.

There will be options for color LCD screen, custom enclosures, etc.

A 32A J1772 plug with a 25-foot cable would be a $149 option - ~$100 cheaper than elsewhere.

If interested, please subscribe to this post and we will post more info (including all schematics / PCB / firmware) in a couple of weeks.

Thanks!
Valery.


----------



## njloof (Nov 21, 2011)

Awesome! Great news, Valery.


----------



## dillond666 (Dec 27, 2010)

Sounds great Valery.......but what is an EVSE? 

Derek


----------



## TEV (Nov 25, 2011)

dillond666 said:


> Sounds great Valery.......but what is an EVSE?
> 
> Derek



" Electric Vehicle Supply Equipment "


" An electric vehicle charging station, also called EV charging station, electric recharging point, charging point and EVSE (Electric Vehicle Supply Equipment), is an element in an infrastructure that supplies electric energy for the recharging of plug-in electric vehicles. "


----------



## rwaudio (May 22, 2008)

Woohoo, just ordered a J1772 socket, now need the evse!


----------



## SHARKBITEATTACK (Nov 12, 2012)

Cool I have an arduino UNO, I wonder which model this project will use


----------



## onegreenev (May 18, 2012)

Im in as I will need more as more conversions are completed. We need a good EVSE Open Source.


----------



## onegreenev (May 18, 2012)

dillond666 said:


> Sounds great Valery.......but what is an EVSE?
> 
> Derek


Well I have always known it as Electric Vehicle Support Equipment. Not supply Equipment, but either works for me.


----------



## Kevin Sharpe (Jul 4, 2011)

valerun said:


> We (http://www.eMotorWerks.com) are about to launch a new open source product - Arduino-based EVSE starting at $100 kit price


Is this open-evse hardware/software?

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


----------



## valerun (Nov 12, 2010)

Kevin Sharpe said:


> Is this open-evse hardware/software?
> 
> http://code.google.com/p/open-evse/


Hi Kevin - 

No, this is our own design. We wanted to reuse the architecture we developed for our charging systems (http://www.diyelectriccar.com/forums/showthread.php/10kw-60a-diy-charger-open-source-59210p52.html) and controllers. This way we can reduce the price further.

We also have all the AC components (relays, current sensors, connectors, etc.) integrated into the main PCB so you are all ready to go once assembled. There will also be a reduced functionality version that will charge your car but not have all the bells and whistles and cost $99 in a kit form, $149 in the assembled form. Including the enclosure.

Hope this helps.

Thanks!
Valery


----------



## valerun (Nov 12, 2010)

SHARKBITEATTACK said:


> Cool I have an arduino UNO, I wonder which model this project will use


It will use Pro Mini 5V but you can use any Arduino - just will have to wire it to the PCB yourself. Arduino code will be fully portable.

V


----------



## Kevin Sharpe (Jul 4, 2011)

valerun said:


> Hope this helps.


It does thanks!

I couldn't find the open source license or schematics on your site.... can I have a link?


----------



## valerun (Nov 12, 2010)

Kevin Sharpe said:


> It does thanks!
> 
> I couldn't find the open source license or schematics on your site.... can I have a link?


Hi Kevin - the product not launched yet. We are going to have a KickStarter campaign open any day now on it - to set up production of $99+ kits and $179+ fully built units.

I will post a link here as soon as we start the campaign.

Thanks,
Valery


----------



## rwaudio (May 22, 2008)

valerun said:


> Hi Kevin - the product not launched yet. We are going to have a KickStarter campaign open any day now on it - to set up production of $99+ kits and $179+ fully built units.
> 
> I will post a link here as soon as we start the campaign.
> 
> ...


Will you have any 50A or 60A cables available?
What exactly will be included?
The control board? 
Contactors?
Display?

I got my J1772 socket today, so looking forward to the EVSE to match.


----------



## frodus (Apr 12, 2008)

Any update on this? Kickstarter?


----------



## tomofreno (Mar 3, 2009)

My two cents on this Valery...wait until you have things far enough along that you feel you can freeze the design and release it with clear/complete documentation. Continue experimenting and changing, but don't make any further releases until you can do the above again. Don't rush to make the latest and greatest available to us because we will only piss and moan that documentation is confusing, parts are missing or not the same as on the BOM, etc. Don't even tell us about it because we will whine that we NEED that on our kit now. Just systematically make periodic releases as they are ready and trumpet the new changes/additions then. You will save yourself (and us) a lot of frustration.


----------



## rwaudio (May 22, 2008)

tomofreno said:


> My two cents on this Valery...wait until you have things far enough along that you feel you can freeze the design and release it with clear/complete documentation. Continue experimenting and changing, but don't make any further releases until you can do the above again. Don't rush to make the latest and greatest available to us because we will only piss and moan that documentation is confusing, parts are missing or not the same as on the BOM, etc. Don't even tell us about it because we will whine that we NEED that on our kit now. Just systematically make periodic releases as they are ready and trumpet the new changes/additions then. You will save yourself (and us) a lot of frustration.


I would have to agree.... I have a Deluxe version of the EV Dashboard but the android app is 10 months late, with every inquiry saying it's a few weeks out. Valery is a brilliant guy and I love the products but from a consumer point of view none of his products are ready for the public.

With that said I'm still looking forward to the EVSE, however now I know what to expect. It will be a good design with no documentation and some missing parts with no real way to mount it elegantly in an enclosure, and if you buy another one in 3-6 months it will be completely different. (I bought two 10kw charger kits 4 or 5 months apart and they are so completely different that none of the enclosure panels I designed for the first one will work with the 2nd.....)

There should also be a time translator....
Valery says 2 weeks = 2 months
Valery says 1-2 months = 8-12 months
Valery says it's in the works = 1-3 years

I hope this isn't taken negatively Valery, you are introducing products we need at a price point we can afford and for that I must commend you. Are you doing way more things at once than you honestly have time for, yes... 

We want to know the things you are working on and what's coming up next, you give us a date of a few weeks and we get excited, but you have a small team working on so many things it's impossible to meet those deadlines.

Keep up the great work, and keep us upadated.
If you need help I'm sure there are lots of us in the community that have skills in PCB design, enclosure design, I'm also sure a lot of us would work for parts....


----------



## frodus (Apr 12, 2008)

Hmmm, well maybe I'll just hold off and wait for more details. Trying to decide between this and the Open EVSE.


----------



## tomofreno (Mar 3, 2009)

rwaudio said:


> ...With that said I'm still looking forward to the EVSE, however now I know what to expect. It will be a good design with no documentation and some missing parts with no real way to mount it elegantly in an enclosure, and if you buy another one in 3-6 months it will be completely different...


 I'm betting it will be better. First off, it is a much simpler assembly than the charger. I built one of the Open EVSE's for my wife and the hardware is simple (EMW announced theirs two days after I built it). Valery said most of his components will be on a pc board so it should be even simpler to assemble. Second, it doesn't require near as much software code as the charger. Third, we've been beating him up (enough I think) for confusing documentation so I'm also betting that will improve. On the other hand, he may be tired of our complaining and only offer it as a finished product, no kit.


----------



## Siwastaja (Aug 1, 2012)

rwaudio said:


> Valery says 2 weeks = 2 months


Hey this is actually pretty good! Last time I promised something in 2 weeks, it took a year!

Prototyping electronics is actually a lot harder than you may think. And at the same time, it is a lot easier than you may think. Most of the things you do are not rocket science, but it takes _surprisingly_ lot of time. It always surprises even experienced developers.

The tiniest tasks take most of the time. Like, finding a lost screwdriver to connect a single wire may take, say, half an hour...

Personally, I feel that I need to give optimistic time tables, even when I know it won't work that fast in reality. A little bit of stress is sometimes the only motivator that works.



> If you need help I'm sure there are lots of us in the community that have skill...


No, this never works. You never get help. You have to do everything by yourself. But it's ok. In some rare occasions when you do get help, you usually end up redoing everything from scratch anyway. (I know I sound kind of negative. But it's the truth. And I'm perfectly fine with that.)

In some cases, you can be lucky to find a _partner_. But it's not a "community" kind of thing. The best you can get from the "community", is feedback. Especially the feedback on documentation is valuable.


----------



## njloof (Nov 21, 2011)

A good tech writer could help document and sell the results...


----------



## valerun (Nov 12, 2010)

rwaudio said:


> I would have to agree.... I have a Deluxe version of the EV Dashboard but the android app is 10 months late, with every inquiry saying it's a few weeks out. Valery is a brilliant guy and I love the products but from a consumer point of view none of his products are ready for the public.
> 
> With that said I'm still looking forward to the EVSE, however now I know what to expect. It will be a good design with no documentation and some missing parts with no real way to mount it elegantly in an enclosure, and if you buy another one in 3-6 months it will be completely different. (I bought two 10kw charger kits 4 or 5 months apart and they are so completely different that none of the enclosure panels I designed for the first one will work with the 2nd.....)
> 
> ...


;-)

you know I love you guys ;-)

Anyway, Kickstarter wasn't super-easy to work with, to say the least. I will spare you the details but it took us 4 weeks to get the submission approved and a couple of times we had to really hunt down people there (there is no way to contact anyone at KS - no email, no phone, all comms are strictly one-way from them to you - kind of like 10 commandments kind of thing ;-))

We almost went to their competitor (much smaller audience, etc, but more friendly) when we finally got blessed with a response. So we are hoping to launch it this week (fingers crossed). Meanwhile, 3 of our prototypes work just fine on our Leafs.

Re community help - I would have to agree with Siwastaja - only thing I can hope for is partners / someone to join the team. I am really missing an Android developer (as you can probably tell, rwaudio ;-/) and some qualified help on documenting / part sourcing / assembly. We just hired a full-timer to do some of the latter 3 but he is relatively new to power electronics so learning curve is tough.

V


----------



## adeyo (Jun 6, 2012)

valerun said:


> ...If interested, please subscribe to this post...
> 
> Thanks!
> Valery.





I'm interested


----------



## valerun (Nov 12, 2010)

All - we are launching our KickStarter campaign tomorrow at 1pm pacific time! WooHoo!

We will be sending out a separate note / post here once it is live and you can participate.

Thanks for your patience!

Valery.


----------



## qryptiq (Dec 29, 2012)

Best luck to you and all involved with


----------



## valerun (Nov 12, 2010)

Hi All - 

EMW JuiceBox project is NOW LIVE ON KICKSTARTER!

http://www.kickstarter.com/projects/1076207974/emw-juicebox-an-open-source-level-2-ev-charging-st

Also, on Engadget: 
http://www.engadget.com/2013/06/24/emw-kick-starts-juicebox-a-99-level-2-diy-charging-station/

Let us know what you think and, of course, back us up! ;-)

Thanks,
Valery & EMW crew.


----------



## rwaudio (May 22, 2008)

I see a premium kit in my future!!

What is the maximum current the included hardware (contactor/relay) is rated for?

Nevermind, found the 60A rating... Backed a premium kit!


----------



## flyguy161 (Jun 26, 2013)

Congratulations on the Kickstarter project.

I have a couple questions before I pledge.

Does the basic package ($109) include GFCI? NEC requires GFCI on all charging stations 120/240v for both indoor and out. GFCI is not mentioned until the premium edition. 

What relays are used to achieve 60A? The picture of the premium edition looks like a TE T9AS1 which is only rated to 30A.


----------



## valerun (Nov 12, 2010)

flyguy161 said:


> Congratulations on the Kickstarter project.
> 
> I have a couple questions before I pledge.
> 
> ...


Hi - thanks for your interest in our project!

Basic package does not include GFCI. It is intended to be more of a plug-in unit that you take with you on the road. It assumes that you plug into a GFCI protected outlet as all new garage outlets should be per code.

Relays used in production units will be 60A relays. What you see on the photos in the campaign are 30A relays, indeed. We have used that version to test operation / logic.

Thanks!


----------



## Caps18 (Jun 8, 2008)

Have you thought about making a "Kil-A-Watt" type of device for 240V appliances to monitor their power usage?

I like the display part of this EVSE and wish more chargers had it.


----------



## valerun (Nov 12, 2010)

Caps18 said:


> Have you thought about making a "Kil-A-Watt" type of device for 240V appliances to monitor their power usage?
> 
> I like the display part of this EVSE and wish more chargers had it.


Thanks Caps18 - we also think that a beautiful display will be one of our great differentiators! 

Re Kill-a-Watt - people expect that kind of device to cost $10. Which is out of the range of what we can afford to do, unfortunately. Basically, you need to be selling millions of units to just break even on something like this.


----------



## emotorwerks (Jun 28, 2013)

Hi All, EMW here.

EMW JuiceBox has reached its initial funding goal on kickstarter. Onward to a Stretch Wi-Fi goal of $40K!

EMW has announced that Juicebox kickstarter campaign has reached its initial funding goal on July 10th, 2013 - with 13 days left to go. Find the project on kickstarter at http://www.kickstarter.com/projects/1076207974/emw-juicebox-an-open-source-level-2-ev-charging-st
Thank you all for your great support! The JuiceBox is now REAL!
On to the stretch goal of $40K to make it a Wi-Fi ready!

If kickstarter reaches $40K goal EMW R&D will write all the support software to make WiFi Shield plug and play. EMW will also launch an online service that will allow you to access your JuiceBox and get stats / analysis / real-time status etc.

EMW will also make WiFi shields available through EMW store and you would be able to add that as an option before we ship your unit. The current 'official' seller of the official Arduino WiFi shield is SparkFun: https://www.sparkfun.com/products/11287. EMW plans to source their own stock and expect to be able to offer that at a better price. EMW team is already testing a couple of shields to make sure they hit the right combination of reliability and cost.

To read more on the latest JuiceBox news and media coverage go to: http://emotorwerks.com/index.php?op...81&subid=460-39b115ed193021f15d2122a07d20f4da

Thanks,
EMW JuiceBox team


----------



## flyinginnet (Apr 19, 2013)

Hi, we put some money for the basic edition, and since the pledge is successful, I just wonder when the basic kit starts to ship.

Does the open source mean schematics and firmware source code? 

Thanks!


----------



## valerun (Nov 12, 2010)

flyinginnet said:


> Hi, we put some money for the basic edition, and since the pledge is successful, I just wonder when the basic kit starts to ship.
> 
> Does the open source mean schematics and firmware source code?
> 
> Thanks!


Hi flyinginnet - thanks for your support! Kits start shipping early August.

Open source everything - schematics, PCB layouts (including Gerber files!), and firmware.

This is going to be awesome!

Thanks,
Valery


----------



## poltergiest (Aug 16, 2013)

I have a juicebox on order, waiting to replace my avcon! I have dabbled a bit in arduino and already have a wifly shield, RN-XV WiFly Module from sparkfun. Since this is built from the same chip will this shield work on the juicebox? No reason to buy another if it works, this one is just sitting around.


----------



## valerun (Nov 12, 2010)

Hi Guys - the first set of design materials and build manual are posted at http://emotorwerks.com/JuiceBox_Public/

Let me know what you think!

Valery.


----------



## valerun (Nov 12, 2010)

150 units shipped! Premium edition to start shipping end of month


----------



## valerun (Nov 12, 2010)

valerun said:


> 150 units shipped! Premium edition to start shipping end of month


V8.6 of Base editions are shipping now. All info at 

http://emotorwerks.com/JuiceBox_Public/8.6/


----------



## Want2race (Dec 17, 2013)

Based on a recommendation Ill post here vs a separate thread. 

So I am on the mild side (very mild...) of this hobby and bought the base edition juicebox. I wanted the premium but availability wasn't there and I am not good at waiting! 

So here is my plan.

I wanted to know output amps but didnt plan to buy the LCD screen at the time. So I went with this : AMP UNIT









At the time it was a decision made out of concern and fear of the arduino stuff. 

A day later I decided to try use the Leafs internal charger.. And my base edition only supports a "charge till" function. So that killed my fear of the arduino and I bought an RTC module and the FTDI module. I really want to be able to set the charger to run from 11pm to 7am with a simple "override" button. 









Now suddenly I am thinking about an LCD Screen to show the time functions but Ill probably wait for the unit to arrive. 
Im thinking for $6 shipped this might be the ticket









I still trying to decide if the base unit has a GFCI circuit or if I need the breaker. V- Any updates? Above it said No for the base. 

Cheers
~J


----------



## valerun (Nov 12, 2010)

Hi J - this is pretty cool mod. 

All Base kits & assembled units now ship with GFCI. There are no non-GFCI options available anymore. 

Thanks,
Valery


----------



## Want2race (Dec 17, 2013)

Valery,
Do you folks use any simulator for your software code? I was playing with one today but had to create much of the circuits. Do you have such a thing? And possible the .board file?

Thanks
-Jonathan


----------



## valerun (Nov 12, 2010)

Not really. We use a super simple diode-resistor base dummy load and the 4 different EVs we have for testing


----------



## foldog22 (Jan 29, 2014)

Want2race said:


> Based on a recommendation Ill post here vs a separate thread.
> 
> So I am on the mild side (very mild...) of this hobby and bought the base edition juicebox. I wanted the premium but availability wasn't there and I am not good at waiting!
> 
> ...


Did you get anywhere with this? I am a complete novice when it comes to programming. I just purchased a Juicebox standard edition, primarily because I didn't want to wait the 4+ weeks on the premium. I would however like to add a display to mine. Please share how your progress is going and if you have any tips?


----------



## valerun (Nov 12, 2010)

foldog22 said:


> Did you get anywhere with this? I am a complete novice when it comes to programming. I just purchased a Juicebox standard edition, primarily because I didn't want to wait the 4+ weeks on the premium. I would however like to add a display to mine. Please share how your progress is going and if you have any tips?


Pls take a look at our manual at https://docs.google.com/a/emotorwer...e-QgHYRQVD4Zl2-oZO3A9gRjJZC4ReH_2jIM_x0/edit# - it now has instructions on how to get all Premium features in your Base unit. 

Basically you can just buy (from our store or other places) an AC-10XX current sensor, u144 LCD, and you got yourself a non-WiFi premium unit in a base enclosure. You can also get a WiFi module with an external patch antenna to get WiFi in a base case (even if you don't have a window for LCD). We now stock that version of WiFi module, as well. Finally, you don't even need a separate shield for WiFi anymore - all necessary layouts are on V8.6 boards already and just need to be populated with a few parts. 

Again, all this is described in the manual. The only tough part is cutting an opening for the LCD. 

V


----------



## Want2race (Dec 17, 2013)

See here http://www.mynissanleaf.com/viewtopic.php?f=26&t=15444


----------



## Want2race (Dec 17, 2013)

valerun said:


> Pls take a look at our manual at https://docs.google.com/a/emotorwer...e-QgHYRQVD4Zl2-oZO3A9gRjJZC4ReH_2jIM_x0/edit# - it now has instructions on how to get all Premium features in your Base unit.
> 
> Basically you can just buy (from our store or other places) an AC-10XX current sensor, u144 LCD, and you got yourself a non-WiFi premium unit in a base enclosure. You can also get a WiFi module with an external patch antenna to get WiFi in a base case (even if you don't have a window for LCD). We now stock that version of WiFi module, as well. Finally, you don't even need a separate shield for WiFi anymore - all necessary layouts are on V8.6 boards already and just need to be populated with a few parts.
> 
> ...


Very cool. Just saw that


----------



## frodus (Apr 12, 2008)

[removed post]


----------



## valerun (Nov 12, 2010)

firmware V8.7.2 posted on JuiceBox site at http://emotorwerks.com/JuiceBox_Public/8.7/50 - Firmware/8.7.2/.

New features:
* Proper interface for a settings menu using the LCD and wireless remote
* Menu option 1: Current limit change at any time via a wireless remote - both for 120V and 240V operation
* Menu option 2: JuiceBox ID printout for WiFi data reporting
* Menu option 3: Clock setup at any time via a remote
* Various refactorings and minor bug fixes

This version matches kits / units V8.7.2 shipping now.

Val


----------



## 7tronics (Jan 29, 2014)

Is there any update on the availability of the Premium JBs ? I ordered at end of Jan and updated mid Feb, but no word yet. 

Thanks!


----------



## valerun (Nov 12, 2010)

Yes - ~90 enclosures are here and we have started shipping them out - the first 20 went out last week. This week we are hoping to get another 20 out. Hopefully even more after that! 

Thanks,
Valery.


----------



## JJSoFla (Apr 6, 2014)

Voltage sensor?

I recently purchased a fully assembled Base JB, and am in the process of upgrading it to a premium JB. I have the LCD, current sensor and remote control working well, but the LCD shows that the JB is running at 120V. This also causes the amount of power shown as delivered in the last charge to be 1/2 of what it should state. 

The voltage at the line terminals of the relay reads 248V. I'm not sure why the display shows 120V, and it is more of a technicality, but I'd like to know how I can get the JB to display the proper voltage.

I am working with EMW to get the WiFly shield working, but other than that, along with the voltage issue, I'm about 90% of the way to all of the premium functions.

Thanks!
Jerry


----------



## valerun (Nov 12, 2010)

JJSoFla said:


> Voltage sensor?
> 
> I recently purchased a fully assembled Base JB, and am in the process of upgrading it to a premium JB. I have the LCD, current sensor and remote control working well, but the LCD shows that the JB is running at 120V. This also causes the amount of power shown as delivered in the last charge to be 1/2 of what it should state.
> 
> ...


Hi Jerry - what is your car? Just checking because if JB thinks it's plugged into 120V, it will also limit the current to 15A. If you have a car with 3.3kw charger, you will not notice the difference. But if you have a car with 6.6kw charger or higher, your charge will be slower than you expect.

The cause for JB to sense 120V when 240V is present is calibration offset. In some of the recent units, calibration procedure might have been applied incompletely. The easiest way to check is to measure (carefully!) the voltage between any ground point and A1 Arduino pin when your JuiceBox is plugged in. A correctly calibrated unit should read a very small but positive voltage (below 100mV). If your unit reads solid zero, it might need to be recalibrated. Calibration resistor is R26 trimpot in the middle of the board. It might be covered with a bead of silicone sealant - remove if needed. Then, while watching A1 pin voltage, slowly turn R26 until you see a small positive value (0-100mV). That's it. Cycle input AC to your JuiceBox and it should read 240V.

Apologies for the inconvenience!

Thanks,
Valery


----------



## JJSoFla (Apr 6, 2014)

valerun said:


> Hi Jerry - what is your car? Just checking because if JB thinks it's plugged into 120V, it will also limit the current to 15A. If you have a car with 3.3kw charger, you will not notice the difference. But if you have a car with 6.6kw charger or higher, your charge will be slower than you expect.
> 
> The cause for JB to sense 120V when 240V is present is calibration offset. In some of the recent units, calibration procedure might have been applied incompletely. The easiest way to check is to measure (carefully!) the voltage between any ground point and A1 Arduino pin when your JuiceBox is plugged in. A correctly calibrated unit should read a very small but positive voltage (below 100mV). If your unit reads solid zero, it might need to be recalibrated. Calibration resistor is R26 trimpot in the middle of the board. It might be covered with a bead of silicone sealant - remove if needed. Then, while watching A1 pin voltage, slowly turn R26 until you see a small positive value (0-100mV). That's it. Cycle input AC to your JuiceBox and it should read 240V.
> 
> ...


Thanks for the reply, Valery. I have a 2013 Ford Fusion Energi, which only pulls 13-14 amps when charging, so the JuiceBox has been giving me a full charge in a little more than 2 hours, even with the 120V limitation. A great improvement over the 6 hours it was taking with the Ford 120V charger!

I attached my meter to A1 and ground, set to 2000mVDC. The voltage read 4mV with no AC applied (probably a calibration issue with the meter). R26 was turned all the way counterclockwise. After plugging in the JuiceBox, A1 still showed 4mV. I turned R26 up until I had a reading of 56mV. I power cycled the JB, and the LCD showed 208V. I tried to charge my car, and the LCD would go up to about 9-10 amps, then the JB relay would click off. After a few seconds, it would attempt to charge again, going to 9-10 amps, then click off again. After 6 attempts to charge, the JB would click off the relay, and show a GFC interrupt, attempt again in 15 minutes. I power cycled, returned R26 to full CCW setting, 4mV, then adjusted until I measured 5mV. After the power cycle, the LCD again displayed 208V. However, the JB went through the same 6 attempts to charge, recycling at 9-10 amps, then returned the GFCI error. Right now, I have turned R26 back down to give a reading of 4mV, to get a full charge before I go to work. The LCD is showing 120V 13A, and is charging just fine.

Any ideas?

Thank you,
Jerry


----------



## valerun (Nov 12, 2010)

JJSoFla said:


> Thanks for the reply, Valery. I have a 2013 Ford Fusion Energi, which only pulls 13-14 amps when charging, so the JuiceBox has been giving me a full charge in a little more than 2 hours, even with the 120V limitation. A great improvement over the 6 hours it was taking with the Ford 120V charger!
> 
> I attached my meter to A1 and ground, set to 2000mVDC. The voltage read 4mV with no AC applied (probably a calibration issue with the meter). R26 was turned all the way counterclockwise. After plugging in the JuiceBox, A1 still showed 4mV. I turned R26 up until I had a reading of 56mV. I power cycled the JB, and the LCD showed 208V. I tried to charge my car, and the LCD would go up to about 9-10 amps, then the JB relay would click off. After a few seconds, it would attempt to charge again, going to 9-10 amps, then click off again. After 6 attempts to charge, the JB would click off the relay, and show a GFC interrupt, attempt again in 15 minutes. I power cycled, returned R26 to full CCW setting, 4mV, then adjusted until I measured 5mV. After the power cycle, the LCD again displayed 208V. However, the JB went through the same 6 attempts to charge, recycling at 9-10 amps, then returned the GFCI error. Right now, I have turned R26 back down to give a reading of 4mV, to get a full charge before I go to work. The LCD is showing 120V 13A, and is charging just fine.
> 
> ...


Hi Jerry - thank you for a very thorough description. 

getting to only 56mV when R26 is at full right stop is very unusual. You should be seeing 1.5-2V when you are at full right stop. Any chance the meter might be off / have low internal resistance that would affect the readings?

The interruption you are getting is due to the high baseline voltage. Due to the fact that wires passing through the sensor are not exactly symmetric, there is often some stray magnetic field that make GFI sensor to produce a small parasitic output voltage. Normally, when your baseline (calibrated) voltage is close to zero, this is not a problem. But if your baseline is too high, this small parasitic output can result in a GFI trip at some low current value.

Do you have a scope by any chance?

thanks,
valery


----------



## Zak650 (Sep 20, 2008)

Valery,
Does the base unit connect up with a home wifi router? If so can the wifi be used to set charge times and amperage?


----------



## crackerjackz (Jun 26, 2009)

valerun said:


> Hi Jerry - thank you for a very thorough description.
> 
> 
> 
> ...





Really dislike seeing you answer in this thread and not answer questions on your 12 kw charger page about a possible known issue with the input voltage because of a variable performance on the pc817 chip of the v13 driver board ... You once told me you should not have to be expected to answer in 24 hours ... Thats fine ... But over 1 week and a half is ridiculous ...


----------



## JJSoFla (Apr 6, 2014)

valerun said:


> Hi Jerry - thank you for a very thorough description.
> 
> getting to only 56mV when R26 is at full right stop is very unusual. You should be seeing 1.5-2V when you are at full right stop. Any chance the meter might be off / have low internal resistance that would affect the readings?
> 
> ...


R26 only needed to be turned a small amount to take the voltage up to 56mV. I only stopped there because you said to keep it under 100mV, although I'm sure it would have been adjustable to a much higher voltage.

I don't have a scope, but is there anything else I might try to solve this problem?

Thanks,
Jerry


----------



## valerun (Nov 12, 2010)

fun stuff for you guys - just featured in InsideEVs.com. enjoy - ;-)

-----
How will YOUR EVSE hold up to the beating of the harsh California weather?! ;-)) EMotorWerks is launching the EVSE Ice Bucket Challenge! 
https://www.youtube.com/watch?v=7OBEMHkMzII
JuiceBox now challenges Schneider and Bosch EVSEs!
---------


----------



## PStechPaul (May 1, 2012)

Since I have been looking at the pilot signal sensing of the SmartCharge12000, I thought I would take a peek at the JuiceBox which generates the signal as would a commercial EVSE. JJSoFla had a problem with his JuiceBox apparently tripping on GFCI, and I see that it has not been answered in this thread. Here is the schematic for V8.6 (latest I could find):










I question how this could work. The 5V Op-Amp has its (+) input connected to GND. With no differential current through the current sense transformer CS2, the voltage on its output will be divided by 680/1 to the (-) input. If the output is low, both inputs will be zero, except for the small voltage that might be imposed on the (-) input due to input bias current. It is unlikely for this to be negative, so a small positive voltage may drive the output to GND, although this is in no way guaranteed, as the offset voltage of the two inputs can vary.

Now, if differential current does flow, a square wave will appear across R2, and this will drive the (-) input positive, and will be inverted so that the output will be driven to the GND rail. However, this square wave will also go negative (below GND) by the forward conduction of zener D2, and this may be enough to drive the output high and will be presented to the Arduino D3 and A1 inputs. Is this how the circuit is supposed to work?

Here is the schematic for the OpenEVSE version. I think it also has some issues, but I think it should work adequately:


----------



## PStechPaul (May 1, 2012)

Editing problem caused double post


----------



## PStechPaul (May 1, 2012)

Here are parts of the start-up and testing procedure for the JuiceBox:



> 5. [OPTIONAL] Plug in your JuiceBox into a 120V outlet protected by GFI and / or a protected power strip
> 6. If no immediate issues (e.g., sparks, smoke, etc), plug your JuiceBox into a 240V outlet
> 7. Wait 15-30 seconds. JuiceBox should cycle the main relay. If that does not happen, something is wrong. Time to debug.
> 8. Plug your J1772 cable into the car
> 9. Relay should close within a few seconds and stay closed


I think there is a safety issue if the main relay cycles when power is applied, without a vehicle or charger connected. 



> 6. Test J1772 operation. There are 2 options:
> a. Build a small test rig (optional but preferred as it will allow to test operation to a larger extent)
> b. Just use your EV
> 
> ...


----------



## crackerjackz (Jun 26, 2009)

The picture you posted says .... Gfi wire and both power wires go through the cs2 power transformer ...??? Why would you pass the gfi wire through the current transformer ? Let alone both lines of 120 ? One line out of a 240 volt circuit is what ive always seen done ? ... Or else your doubling your current lecture ... Unless the current transformer isnt a typical round eye sensor ?


----------



## PStechPaul (May 1, 2012)

A ground fault current interrupter (GFCI) measures the difference between the current going to the load and that which returns. By putting both wires through the "donut hole" the phase currents should balance, but if they differ, that means that some current is going elsewhere, most likely to ground through leakage, such as a person's body, and 20 mA is the usual trip point.

I don't know what the GFI wire is, and why it is supposed to go through the CT. I couldn't find an overall schematic of the JuiceBox and the photos in the build notes are not really clear. One thing I saw there that I did not like was the use of solid wires from the PCB to the power supply. I have never seen a piece of professionally designed industrial or commercial equipment that used solid wires to connect separate circuit elements, except perhaps sealed items such as a $2 wall-wart.

Other things I found questionable were:

1. The use of a +/- 15V regulated supply with linear 12V regulators for the +/- 12V pilot signal (not necessary)

2. The use of 5% carbon film resistors throughout this design and the charger. Temperature stable 1% metal film resistors are less than $0.02 each. And I use 1/4W rather than 1/8W except for SMDs where I use 1/8W 0805 (also 1% metal film)

3. The choice of an expensive ($2) precision op-amp (LM7321) to generate the +/- 12V pilot signal

4. Direct connection of the Arduino analog pins to measurement points rather than using R-C filters (which also provide protection).

These are minor "nits" and not serious issues. 

[edit] I finally found the BOM by doing a general DogPile search on the part number of the precision +12V regulator (BDJ2A3WEFJ-E2) as specified on the schematic http://www.emotorwerks.com/JuiceBox_Public/8.1/30 - BOM/JuiceBox BOM - V8.0.xlsx

The link in the build notes goes to 8.6 but the BOM is actually in 8.0 as shown above. The part number is incorrect. It is actually 
http://www.digikey.com/product-search/en?vendor=0&keywords=BDJ2GA3WEFJ-E2CT-ND

It seems that there are some parts on the BOM that do not appear on the schematic. Particularly, the problematic PC817 optoisolator U2, used for input voltage measurement, and the second CT (CS1) for current sensing (actually neither are on the BOM, and the schematic shows only CS2).

I had mentioned the issue with the 5% carbon film resistors used in these products. Here are the specs:
https://www.seielect.com/catalog/SEI-CF_CFM.pdf

Note that the tempco is +/- 400 PPM/DegC for under 10k and as much as -1500ppm/degC for above 1M. Considering that these devices are expected to operate properly from, say, -20C to 65C, or over 85C, that translates to +/- 3.4% and 12.8%, added to the initial tolerance of 5%, so if these resistors are used as voltage dividers or for pilot signals, the error can be significant. These resistors are about $0.02 each in 100 piece quantity, while a 1/4W 1% 10k with 100 ppm/DegC is about $0.03 each in 100 piece quantity:
http://www.digikey.com/product-detail/en/MFR-25FBF52-10K/10.0KXBK-ND/13219

[edit2] Looking at the firmware for Ver8.9 I see that the GFCI is now accomplished with an LM1851 dedicated IC. But no schematics. They were "coming soon" in May. It boggles my mind that a product can have been designed, manufactured, and sold, without current schematics.


----------



## crackerjackz (Jun 26, 2009)

I very well know how a gfi breaker works ... I just completly dont understand why one would pass a neutral gfi wire through an amp reading device with two other power wires ???? ...


----------



## PStechPaul (May 1, 2012)

It looks like the "GFI wire" is the 12VDC coil connection to the main relay:










This shows the L1 and L2 wires, with the yellow relay coil wire also passing through. For a 120V EVSE, one of these wires is neutral:










Also, I found that relay on Amazon, and it does not look like it can handle the 80 amps that it's rated for. It is the same size as 30A general purpose relays, and it's a Chinese copy where it is not unusual for items to be over-rated to sell to unsuspecting buyers. Also, the review of this product indicates that "it has trouble opening" and "needs a stronger spring". 
http://www.amazon.com/JQX-62F-2Z-Coil-Voltage-Electronmagnetic-Relay/dp/B008MU0IU2

Here is an industrial contactor rated at 50 amps resistive, and it is about $240. There is a reason for that cost. Reliability and liability. The Chinese contactor has "lie-ability"!
http://www.galco.com/buy/Cutler-Hammer-Div-of-Eaton-Corp/C25DNA2401R










Most industrial contactors do not have 12V coils. 24VDC and 120VAC are most common, and you can get a 50A (90A resistive) two pole contactor with a 24 VDC coil for about $60:
http://www.galco.com/buy/WEG-Electric/CWM50-00-20V18
http://www.galco.com/techdoc/weg/cwm50-00-20v18_ts.pdf


----------



## crackerjackz (Jun 26, 2009)

Valery ... Why would you make two power lines and a contactor coil wire pass through the same current loop ? What are you trying to detect ?


----------



## PStechPaul (May 1, 2012)

I found out how that extra wire is being used (it's not the coil wire). It connects a 10k 2W resistor across the 120V or 240V line for a simulated 12 or 24 mA fault. I think there is a second small relay on the board that does this. This is actually shown on the schematic:










Here is the code that does this trick:


```
// now check for a stuck relay and measure input voltage 
  ResetGFI(); // this function also enables the D-latch on GFI
  // force the GFI pin - this connects J-side AC through a 10k resistor into a GFI test wire loop that goes through the sensor
  // this simulates ~12mA RMS current imbalance (on a 120V supply; 24mA on a 240V supply) and will normally trigger 
  // a GFI fault - but ONLY if AC voltage IS present on the output of the relay (J-side AC)
  digitalWrite(pin_GFItest, HIGH);

  // stuck relay test only possible if GFI circuit is operational
#ifdef GFI
  delay(100); 
  // by now, if the trip occurred, the GFI trip flag should be set. blanking time does not apply as timer0=0 at this point
  if(GFI_tripped==1) {
    // we have a stuck relay, throw an error
    printErrorMsg(F("STUCK RELAY! \nUNPLUG &\nContact us\nExiting..."), 30);
    while(1); // halt
  }
#endif

  // stuck relay test passed
  // measure input voltage now
  // for this to work, we need to hold GFI latch in reset!
  digitalWrite(pin_GFIreset, LOW); // active low
  setRelay(HIGH);
  // wait for settling (RC on the pin is ~0.1s so need to wait at least for 0.5s to get within 99% of the actual value
  // but not too long or we will burn out our 10k resistor on 240V...
  delay(500); // has to be more than 20-30 cycles of the line frequency so that the phase doesn't matter
  inV_AC=read_V(); // take a sample   
  digitalWrite(pin_GFItest, LOW);
  setRelay(LOW);  
  ResetGFI();
```


----------



## valerun (Nov 12, 2010)

PStechPaul said:


> However, this square wave will also go negative (below GND) by the forward conduction of zener D2, and this may be enough to drive the output high and will be presented to the Arduino D3 and A1 inputs. Is this how the circuit is supposed to work?


correct. diff voltages measured here at the trip level are on the order of 5 millivolts. No forward conduction of the zener at that level so no disturbance of the signal


----------



## PStechPaul (May 1, 2012)

Here is a first draft of a proposed alternative design. This schematic shows both external parts and those on the PCB. Connectors would be added as needed.










Some features of the design:

1. Single +24 VDC power supply on the input 85-264 VAC mains

2. Virtual ground providing +/- 12 VDC for the analog circuitry and pilot voltages

3. +5 VDC for the processor. I show a 14 pin $2 PIC, but an Arduino could be hacked into the circuit instead. 

4. Heavy duty 4 pole x 40A contactor with a 24 VDC coil, driven with a power MOSFET through an optoisolator. It could be driven by a PWM signal to reduce power. 

5. Optional opto-SCR to cut off power to charger quickly to avoid contactor arcing, welding, and degradation. Could also be used for zero voltage turn-on or even phase-controlled soft start.

6. Two current sensors, one for each line. Outputs in series and balanced to detect ground fault current. Also reads one CT for accurate current reading.

7. Differential amplifier to read input voltage across mains. Uses fusible resistors and low current for safety.

8. All AC voltages and currents are sampled at up to 600/sec making it possible to read average or true-RMS.

9. Pilot signal is provided by using opto-isolators with 1k resistor to +12V and -12V rails.

10. Pilot signal is monitored at each transition to detect charger/car change of state within 1 mSec.

11. Bluetooth (or serial) connection which could also be used for a display and/or control keys.

There will need to be some additional components or some changes as determined by further analysis and testing. This design took about four hours from start to where it is as you see it. Most of the components have attributes such as part number and pricing and a BOM can be made by running a VBA script. PCB decals are also included and the job can be connected to the PADS Layout editor for parts placement and routing. Once parts are physically placed as desired and required for proper function, the autorouter can route the board according to design constraints set up according to track width and spacing. Then it can be cleaned up manually, and the parts can be renumbered so that they are easy to find. The Gerbers can then be created and sent to FreeDFM for a manufacturing analysis, and then can be sent to the PCB fab for prototypes.

If I were sufficiently motivated, I could have the boards and components in my hands in two weeks. I am happy to provide this as open source for those who may benefit from it. I would also welcome suggestions and proposals for changes of modifications. Please ask questions about any of the design elements that may not be clear or correct. I also have a PDF which is much clearer:

http://enginuitysystems.com/files/EMW/EVSE PCB.pdf


----------



## valerun (Nov 12, 2010)

PStechPaul said:


> Here is a first draft of a proposed alternative design. This schematic shows both external parts and those on the PCB. Connectors would be added as needed.
> 
> 
> 
> ...


Awesome! but why 4-pole contactor?


----------



## PStechPaul (May 1, 2012)

40 amp contacts in parallel for 80 amps.


----------



## crackerjackz (Jun 26, 2009)

PStechPaul said:


> 40 amp contacts in parallel for 80 amps.



The difference for a 80 would only be a few dollars more ... Ill check our prices on them .... We only hold allen bradley contactors in stock  ...


----------



## PStechPaul (May 1, 2012)

One reason I chose the four pole was that they are available for cheap ($6) at www.mpja.com, although looking again they are 25A 240VAC inductive and 35A 600V resistive. Even so, I'd trust one of these 4PNO 24 volt coil _contactors_ much more than the Chinese 80A rated DPDT _relay_ which looks much more like a 30A P&B or Magnecraft relay. Also a 4PNO 40A has a smaller form factor than a 2PNO 80A, and the two pole versions are rare in larger sizes. 3 pole are most common, and 4 pole are also readily available.


----------



## crackerjackz (Jun 26, 2009)

Every four pole contactor ive ever seen was 3 power contacts and 1 normally open control contact not made to hold power ...


----------



## PStechPaul (May 1, 2012)

We (ETI) use lots of 3 and 4 pole contactors in our high current breaker test sets. They are available from ABB, Square D, and American Solenoid (Kraus & Naimer) among others. They can be fitted with auxiliary pilot contacts, usually about 5A 600V rated.

Here's the $6 contactor I suggested:

http://www.mpja.com/24VDC-4PST-NO-PB-25A-Contactor/productinfo/18230%20RL/










http://www.ncindustrialsupply.com/kraus-naimer-contactor-cat-s1000b120-0031-120vcoil-nob/


----------



## valerun (Nov 12, 2010)

PStechPaul said:


> We (ETI) use lots of 3 and 4 pole contactors in our high current breaker test sets. They are available from ABB, Square D, and American Solenoid (Kraus & Naimer) among others. They can be fitted with auxiliary pilot contacts, usually about 5A 600V rated.
> 
> Here's the $6 contactor I suggested:
> 
> ...


interesting. but i don't think using 2 poles to share current is UL-able... At least not without at least some derating...


----------



## valerun (Nov 12, 2010)

do you have a good suggestion for an inexpensive 2-pole 30-40a ul-listed / recognized contactor?


----------



## valerun (Nov 12, 2010)

PStechPaul said:


> Also, I found that relay on Amazon, and it does not look like it can handle the 80 amps that it's rated for. It is the same size as 30A general purpose relays, and it's a Chinese copy where it is not unusual for items to be over-rated to sell to unsuspecting buyers.


We have done extensive testing on these, loading them up to a full rated current (80A). 30C over ambient is what we have observed pretty consistently. 

As to the size comparisons, may I suggest you guys look at these UL-apploved 30A relays: http://www.digikey.com/product-detail/en/T9AS1D12-5/PB1014-ND/1095335?


----------



## PStechPaul (May 1, 2012)

I have seen these, and I may have a few that I got a long time ago. According to the specifications, they appear to be capable of 30 amps, especially if switched under low current, non-inductive, and low capacitance conditions. But somehow I think there must be some reason for the huge difference in size and cost between these and full size industrial contactors.

http://www.te.com/commerce/Document...&DocNm=1308242_T9A&DocType=DS&DocLang=English


----------



## crackerjackz (Jun 26, 2009)

valerun said:


> We have done extensive testing on these, loading them up to a full rated current (80A). 30C over ambient is what we have observed pretty consistently.
> 
> As to the size comparisons, may I suggest you guys look at these UL-apploved 30A relays: http://www.digikey.com/product-detail/en/T9AS1D12-5/PB1014-ND/1095335?


ive seen a few heater systems using these contacts to turn on and off the elements ... ive seen as much as 20-24 amps passing in them . I have replaced a few but nothing not normal considering wear and tear , Ive always replaced them with allen bradly contactors just because I have them in stock in the truck .but I always thought they looked way to small to take the full load ... nice to see the spec sheets  ... I think the systems were dettson central heating systems .


----------

