# DIY J1772 EVSE sans $$$



## bruceme (Dec 10, 2008)

Is there any general interest for a simplified "mini" EVSE project that's truly cheap. 240V/30A J1772-style compatibility and safety shut-off (but without over-current/over-volt sensors, monitoring or built-in GFI).

- Mini EVSE circuit board $20 
- Relay $8
- Electrical box $8
- PVC Pipe $3
- Pin Insert $5
- Pins $5
- 8ga, 4-wire rubber cable $2/ft

Total cost: $89










Just wondering if this is a one-off project for myself, or something a wider audience may find appealing.

-Bruce


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## swoozle (Nov 13, 2011)

Here's a vote of interest for part of it: I have an existing EVSE/plug setup but I am interested in your low-cost plug handle assembly for use in an adapter cable.

I'd be very surprised if there wasn't general interest for the project as a whole.


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## TEV (Nov 25, 2011)

I am interested in the "brain" and if it can be modified to work on a 240V/50A input. My charger can take 43A from a 240V source.


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## F16bmathis (Jun 6, 2008)

I converted my S10 to J1772, the Volts EVSE plug was always hard to pull out and yesterday it broke. While soldering a wire back onto the pin, I overheated the pin, so the plastic must have melted, pin won't stay in place. I've also had numerous ground faults shown on a Volts EVSE, probably from the loose pin.

I'm done with 1772, going back to locking L6-30's

P.S. Traded in my Volt for a new Camaro 2 SS. Man that thing sucks gas! Anyone need a good 220V 1772 charger?


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## mweisman (Mar 20, 2013)

Bruce,
I saw your postings on the openEVSE site and your plug design on Shapeways...are you going to start selling these (or the design)? I'm very interested in building my own setup but the cable and plug are ridiculously expensive.
Also, it looks like your using an OSH Park control board, is that correct? Did you have this made up or is it one of the OpenEVSE boards.

If you looking to do another OSH Park run, I'd be willing to buy one of the boards and a parts list and connector...I've through that putting together some type of full kit that included board, parts (or parts list), box, cables, connector, etc. would go over very well with the DIY crowd....however the finance manager in the house won't let me invest some $ to test out the theory. 

Let me know! I still vary interested in what you have going there.

Matt W
Milwaukee, WI
'13 Silver Volt "Zap"


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## mweisman (Mar 20, 2013)

f16...
How much for the L2 EVSE? Is it the unit with the bad pin? What kind is it?


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## F16bmathis (Jun 6, 2008)

mweisman said:


> f16...
> How much for the L2 EVSE? Is it the unit with the bad pin? What kind is it?


The bad pin is on the socket in the spare EVSE I had for my Volt. The L2 charger works great, just don't need it anymore. This model was going for $1750 brand new...

clipper creek model ds100, make an offer...

I also have a good Volt EVSE with a bad plug. The black powered pin is bad, and the plug was bumped into causing the end to fall off and so I had to tear it apart and rewire it, so...


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## mweisman (Mar 20, 2013)

F16
The ds100 out of my price range. Do you want to sell the Volt charger?

Matt W
Milwaukee, WI
Zap - '13 Silver Volt


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## swoozle (Nov 13, 2011)

Please take the sales talk PM or at least to a thread in the classifieds section.


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## evmetro (Apr 9, 2012)

F16bmathis said:


> I converted my S10 to J1772, the Volts EVSE plug was always hard to pull out and yesterday it broke. While soldering a wire back onto the pin, I overheated the pin, so the plastic must have melted, pin won't stay in place. I've also had numerous ground faults shown on a Volts EVSE, probably from the loose pin.
> 
> I'm done with 1772, going back to locking L6-30's
> 
> P.S. Traded in my Volt for a new Camaro 2 SS. Man that thing sucks gas! Anyone need a good 220V 1772 charger?


A bad j plug? Evse problems? No way! F16, congrats on scrapping the J. In case you have not seen any of my rants, I am the guy who thinks it is crazy to equip an oem EV with nothing but a plug that does not fit any power grid on the globe.


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## evmetro (Apr 9, 2012)

Bruce, I may be interested in one of these. I have considered installing one of these things on one of mine. (IN ADDITION to my plug that fits every household in the USA, and my 50 amp 220 plug) Would it be a big problem to make a kit like this that is 50 amps? I don't know where there are any J plug stations in my area, but it might make for a selling point if somebody thinks that there are J plug stations on every corner.


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## dladd (Jun 1, 2011)

evmetro said:


> Bruce, I may be interested in one of these. I have considered installing one of these things on one of mine. (IN ADDITION to my plug that fits every household in the USA, and my 50 amp 220 plug) Would it be a big problem to make a kit like this that is 50 amps? I don't know where there are any J plug stations in my area, but it might make for a selling point if somebody thinks that there are J plug stations on every corner.


they added 6 more public EVSE's to my city last week! It was just the push I needed to upgrade my charger and add j1772 capability.  I don't plan to use j1772 at home though, I'll either use a 14-30, or a good old fashioned 5-15 outlet for normal overnight charging when there is no hurry.


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## bruceme (Dec 10, 2008)

So yeah... I bought a Chevy Volt to keep my Leaf company in the garage, now I need another L2-EVSE. I've been using my OpenEVSE (great project, just not this) now I want to get my TinyEVSE (this project) back into gear.

I started debugging my circuit and program again.

Couple things...

#1 - My origonal state detection algorithm sucked. So I stole the one from OpenEVSE. They basically pole 100 times as fast as possible and record the max. If the min is above a baseline threshold (stuck diode), the max value determines the desired state. They "debounce" the state to cover transients. OpenEVSE uses a timer, I did a simple version that just counted the number of times a state change was requested... 5 is enough to consider it a solid change.

#2 - My circuitry just doesn't work, I think I need to re-think some things. First, the DigiStamp (Attiny85) is drawing far too much current (getting too hot), I need to bread board the circuit to see what's drawing what.

#3 - I don't really know where the real cross-over values are for the state changes. Wish I could debug a digistamp!

#4 - I'd like to improve the circuit to include the OpenEVSE GFCI, I swear that's the last thing I'll steal from them.

Otherwise the project is still very simple and very cheap... $50!


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## Newbiee (Feb 16, 2011)

very interested in your project!!! i was going to try and take on the openevse project but am actually intimidated to do so. A simplified and lower cost version would be perfect!


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## ga2500ev (Apr 20, 2008)

evmetro said:


> A bad j plug? Evse problems? No way! F16, congrats on scrapping the J. In case you have not seen any of my rants, I am the guy who thinks it is crazy to equip an oem EV with nothing but a plug that does not fit any power grid on the globe.


Is this decision not based on a safety issue? Virtually every socket that is in common use on the power grid is a live socket. And most do not have GFCI protection. Also overcurrent protection is limited to a circuit breaker or fuse.

So by forcing an unusual socket, car manufacturers can guide their users towards the equipment with appropriate safety features.

Now I may agree that the J1772 plug is awful (and expensive). But I can understand the rationale for forcing a smart safety plug for an EV.

ga2500ev


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## ga2500ev (Apr 20, 2008)

bruceme said:


> So yeah... I bought a Chevy Volt to keep my Leaf company in the garage, now I need another L2-EVSE. I've been using my OpenEVSE (great project, just not this) now I want to get my TinyEVSE (this project) back into gear.
> 
> I started debugging my circuit and program again.
> 
> ...


Dumb question: How exactly do you steal something that has been freely offered to you?

The OpenEVSE project is open on purpose. And you are right in line with the spirit of the project by offering your designs to this community.

ga2500ev


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## bruceme (Dec 10, 2008)

Oh the power of metaphore


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## bruceme (Dec 10, 2008)

I finally got it working!

see my blog


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## rmay635703 (Oct 23, 2008)

Bruce I am looking to get a cheap 3ft long j1772 extension cable made up so I can add 220vac to my 110vac EVSE.

I need to know where you get your stuff so cheaply.

My idea is simple, pass on all the signal information through the extension cable but attach a single wire of reverse polarity 110vac from a 2nd nearby outlet making 220vac and allowing my 110vac charger to stay alive ignorant of the 220vac to the car.

If this sounds impossible I need to know how much it is to have a standard openevse signal generator but use your original idea of something that just works.

So in other words a BOM.

Thanx
Ryan


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## kortas (Apr 18, 2012)

maybe something like this:
https://github.com/kortas87/simple-evse/wiki

pictures are a bit old.. but now we are using smaller sealed 12V power supplies and I have found small 32A relay which fits inside the connector...


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