BareEVSE - an EVSE circuit for under $5

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I have seen two tiny dogs completely sever the insulation and copper in half on the LEAF 12G wire. Very small dogs. The main point is that an EVSE should be properly designed and tested to meet all the compliance issues. The US is litigious when it comes to blame for any matter small or large. Not to mention many DYI people are clueless and will put 50A plugs on cords that should not have one. When you post such directions in detail you should make full and complete disclosure of all known and possible unknown considerations. I would bet that if you lived in the US and had any assets you would think twice about not making such clear disclaimers. Do not underestimate the stupidity and incompetence of people that are willing to save even a few dollars. I have been in the EV community for a long time and have seen some crazy charging stuff. Having a tech discussion is one thing but providing detailed instructions on building high-voltage supply equipment without better warnings is another. I love to tinker but I also don't like to see people or the EV community getting hurt. It may help if you post your location as well as your first post on this forum was a detailed DIY low-cost charge cord with no introduction, which is fine but a bit odd. As I said before, these diagrams are noting new or special and have been done many times before but usually with consideration. This is not a tech forum, there are people here that amy try this that have no business making such an item. None of this means it's not worth talking about but in full context and disclosure for location and audience.
PS, when someone screws up their EV, which they will, they will still blame you even if you warned them. Not sure if you have been in this position before but it is almost inevitable over time. I have a custom integration business and this stuff happens even when people are informed but today many folks don't want to hear it. Check out the EV Charge America threads. Because your are not accountable from afar does not mean you should be extra responsible in warning people about risks. I am almost certain that if you were part of a local community where you were directly accountable to any negative ramifications you would have posted more cautiously. I would have no issue with your post if your were more clear about the risks and less dismissive based on comparative arguments. Food for thought.

Here is some dog food, dog was the size of handbag and the EVSE was from a LEAF.

rkr24g.jpg
 
Neither the "Bare" EVSE or that European one are compliant with the NEC (National Electrical Code) here in the US. This means you would be in violation if you used such a device.

Here are some snippets:
Code: 
NEC 625.18 Interlock:
Electric vehicle supply equipment shall be provided with an interlock that de-energizes the electric vehicle connector and it's cable whenever the electrical connector is uncoupled from the electric vehicle.
Note it specifically states "and it's cable".

Code: 
NEC 625.19 Automatic De-Energization of Cable:
The electric vehicle supply equipment or the cable-connector combination of the equipment shall be provided with an automatic means to de-energize the cable conductors and electric vehicle connector upon exposure to strain that could result in either cable rupture or separation of the cable from the electric connector and exposure of live parts. Automatic means to de-energize the cable conductors and electric vehicle connector shall not be required for portable cord-and-plug-connected electric vehicle supply equipment intended for connection to receptacle outlets rated at 125 volts, single phase, 15 and 20 amperes.

Code: 
NEC 625.22 Personnel Protection System:
The electric vehicle supply equipment shall have a listed system of protection against electric shock of personnel. The personnel protection system shall be composed of listed personnel protection devices and constructional features. Where cord-and-plug-connected electric vehicle supply equipment is used, the interrupting device of a listed personnel protection system shall be provided and shall be an integral part of the attachment plug or shall be located in the power supply cable not more than 300 mm (12 in.) from the attachment plug.

Code: 
NEC 625.25 Loss of Primary Source:
Means shall be provided such that, upon loss of voltage from the utility or other electrical system(s), energy cannot be back fed through the electric vehicle and the supply equipment to the premises wiring system unless permitted by 625.26.

You cannot avoid a relay, nor can you put the relays in the handle and still be code-compliant. Anyone selling such a device in the US will likely get their pants sued off. Even if someone builds their own and then has some problem, such as a fire, they may be at risk of having insurance coverage denied. CE compliance may be enough in Europe, but has no merit here in the US.

-Phil
 
Ingineer said:
Code: 
NEC 625.19 Automatic De-Energization of Cable:
Code: 
 Automatic means to de-energize the cable conductors and electric vehicle connector shall not be required for portable cord-and-plug-connected electric vehicle supply equipment intended for connection to receptacle outlets rated at 125 volts, single phase, 15 and 20 amperes.
Click to expand...

Thanks for pointing that out. I really appreciate that.
I certainly do not condone anything that is illegal or violates the local electrical code.

I will revise my initial post to warn that the US electrical code only allows EVSEs rated up to 125V 20A to be used without a relay located at the mains connection.

Ingineer said:
Connecting power to an asleep charger defeats the internal pre-charge system and if this happens, it can be catastrophic!
Click to expand...

Would you be so as kind as to substantiate that statement with some technical insights. Many thanks.
 
BetterLeaf said:
Ingineer said:
Code: 
NEC 625.19 Automatic De-Energization of Cable:
Code: 
 Automatic means to de-energize the cable conductors and electric vehicle connector shall not be required for portable cord-and-plug-connected electric vehicle supply equipment intended for connection to receptacle outlets rated at 125 volts, single phase, 15 and 20 amperes.
Click to expand...

Thanks for pointing that out. I really appreciate that.
I certainly do not condone anything that is illegal or violates the local electrical code.

I will revise my initial post to warn that the US electrical code only allows EVSEs rated up to 125V 20A to be used without a relay located at the mains connection.
Click to expand...

I'm not an expert at reading NEC but I don't think you can take it out of context like that. I think that exemption only applies to the requirement of automatic de-energization with regards to strain or cable rupture/separation.
 
QueenBee said:
I'm not an expert at reading NEC but I don't think you can take it out of context like that. I think that exemption only applies to the requirement of automatic de-energization with regards to strain or cable rupture/separation.
Click to expand...

Yes, I think you might have a point. Thank you.

But under this 625.13(A) NEC proposal (which I could not determine if it has already passed) and the 2008 NEC (says the same thing in that regard) I think 125V is OK because it does not need to follow 625.18, 19, and 29 which Phil qouted:

Code: 
625.13 Electric Vehicle Supply Equipment Connection. Electric vehicle supply equipment shall be permitted to be cord 
and plug connected to the premises wiring system in accordance with ONE of the following: 
(A) Electric vehicle supply equipment intended for connection to receptacle outlets rated at 125 volts, single phase, 15 
and 20 amperes.
(B) Electric vehicle supply equipment that is rated 250 volts maximum and complies with all of the following: 
(1) It is part of a system identified and listed meeting the requirements of 625.18, 625.19, and 625.29

Please correct me if this interpretation is incorrect.

It would really make sense for the local electrical code to at least allow the voltage and amperage that people are commonly using with regular extension cords to be connected directly.
 
I have also been developing a similar low cost EVSE. I have built a working prototype with relays and have been using it regularly, the relays enable only when the car requests, and disable when the plug is removed from the car.
I was waiting until I get a few v1.0 units built and tested before sharing my plan, they will be very similar to the chargeAMPS version, but it seems BetterLeaf beat me to it.
I started with a 555 timer, but I found that it was not stable enough, I sourced all my components to remain stable with large temperature swings in mind. I ended up using a quad op-amp, temperature rated as low as -40C I think.
I also will never use electrical tape, my proto is encapsulated in epoxy made for electronics.

My initial experiments showed that plugging a live line into the leaf regardless of pilot signal did not result in charging, rather, an error came up, I decided that relays were mandatory.

I am not following NEC or anything else of that matter, my criteria is based on the following
is a feature required to charge the car?
yes? keep it.
no? leave it out.
this includes GFCI being left out as my intended application is at work where the 120V 20A outlets already have GFCI.
as for safety concerns about live cables, they are unfounded as it is the exact same risk in any other extension cord.

I will eventually have a version that I think I can sell that will have GCFI as an option, will be 50ft long, it will be intended for L1 use and be about half the cost as any commercial EVSE. It also will not be damaged if the end user decides to try 240V for whatever reason.
I will also have a version with a switch to be able to control the pilot duty signal, all the electronics and relays are housed in the charger head. (no ugly box on the wire, with the exception of the GFCI if added on)

I am currently debating if I should make it open source or not. I guess it depends on the feedback I get from locals who I will get to test my v1.0 units.
 
jclemens said:
I have also been developing a similar low cost EVSE. I have built a working prototype with relays and have been using it regularly, the relays enable only when the car requests, and disable when the plug is removed from the car.
I was waiting until I get a few v1.0 units built and tested before sharing my plan, they will be very similar to the chargeAMPS version, but it seems BetterLeaf beat me to it.
I started with a 555 timer, but I found that it was not stable enough, I sourced all my components to remain stable with large temperature swings in mind. I ended up using a quad op-amp, temperature rated as low as -40C I think.
I also will never use electrical tape, my proto is encapsulated in epoxy made for electronics.

My initial experiments showed that plugging a live line into the leaf regardless of pilot signal did not result in charging, rather, an error came up, I decided that relays were mandatory.

I am not following NEC or anything else of that matter, my criteria is based on the following
is a feature required to charge the car?
yes? keep it.
no? leave it out.
this includes GFCI being left out as my intended application is at work where the 120V 20A outlets already have GFCI.
as for safety concerns about live cables, they are unfounded as it is the exact same risk in any other extension cord.

I will eventually have a version that I think I can sell that will have GCFI as an option, will be 50ft long, it will be intended for L1 use and be about half the cost as any commercial EVSE. It also will not be damaged if the end user decides to try 240V for whatever reason.
I will also have a version with a switch to be able to control the pilot duty signal, all the electronics and relays are housed in the charger head. (no ugly box on the wire, with the exception of the GFCI if added on)

I am currently debating if I should make it open source or not. I guess it depends on the feedback I get from locals who I will get to test my v1.0 units.
Click to expand...


I am struggling to think of a downside to making it open source, unless you are planning on selling it.
If you open it up, you will get all sorts of feedback. It'll be on you to differentiate the bullshit from the gems, but undoubtedly there will be some gems in there (even if hidden under the aforementioned). The feedback will allow you to improve your design, and will give others more confidence in your design, hence widening your audience

So +1 for opening up your designs!

Dave
 
BetterLeaf, THANK YOU FOR SHARING!!

I am a Mercedes Smart Electric car owner and the EVSE that came with it doesn't work on my garage, even after the electrician told everything is ok. But the EVSE works on others garages.

I am looking to make a cheap and simple EVSE for me, and I want something OpenSource. I mean cheap mostly in time and risk to build it and have it working. OpenEVSE would be ok for me if I could buy it as any other product, if I could get it assembled and tested, have it in 5 days in my home. Since it is not the current state of OpenEVSE, I need to wait a lot or build it by myself, so, your BareEVSE is cheap in time and simplicity - that's what I am looking for.

Also latest OpenEVSE is BIG, uses an LCD that I would not use most of the time - I am looking for someting very small (just as you did) and that works with the same current - maybe no more than some little switchs to choose from 4 different current values.

Again, thank you for sharing, you helped me a lot! Thanks.

Pictures of my Mercedes Smart Electric car.
 
8bits said:
BetterLeaf, THANK YOU FOR SHARING!!

I am a Mercedes Smart Electric car owner and the EVSE that came with it doesn't work on my garage, even after the electrician told everything is ok. But the EVSE works on others garages.

I am looking to make a cheap and simple EVSE for me, and I want something OpenSource. I mean cheap mostly in time and risk to build it and have it working. OpenEVSE would be ok for me if I could buy it as any other product, if I could get it assembled and tested, have it in 5 days in my home. Since it is not the current state of OpenEVSE, I need to wait a lot or build it by myself, so, your BareEVSE is cheap in time and simplicity - that's what I am looking for.

Also latest OpenEVSE is BIG, uses an LCD that I would not use most of the time - I am looking for someting very small (just as you did) and that works with the same current - maybe no more than some little switchs to choose from 4 different current values.

Again, thank you for sharing, you helped me a lot! Thanks.

Pictures of my Mercedes Smart Electric car.
Click to expand...

I would consider making an open EVSE or buy something that is made properly. Since you are not in the USA you don't have to worry about the liability and code violations this presents but it lacks basic common sense design and safety. I know products are expensive there but you may have better options. Also, reliability is something to consider as well.
 
EVDRIVER said:
I would consider making an open EVSE or buy something that is made properly. Since you are not in the USA you don't have to worry about the liability and code violations this presents but it lacks basic common sense design and safety. I know products are expensive there but you may have better options. Also, reliability is something to consider as well.
Click to expand...
"buy something that is made properly" ---> can you please suggest me? as I told, the original from my car doesn't work and so I will need to "disable" some safety, probably the earth resistance measure.

I have experience to program firmware (for ARM mainly) and I can make my own small prototype boards -- I will do for sure my EVSE using OpenEVSE and BareEVSE information!!! :) -- I am thankfull to both projects!
 
8bits said:
as I told, the original from my car doesn't work and so I will need to "disable" some safety, probably the earth resistance measure
Click to expand...

Did your electrician have any ideas on why your garages electrical system is different than normal and thus why the EVSE enters a fault state?
 
QueenBee said:
8bits said:
as I told, the original from my car doesn't work and so I will need to "disable" some safety, probably the earth resistance measure
Click to expand...

Did your electrician have any ideas on why your garages electrical system is different than normal and thus why the EVSE enters a fault state?
Click to expand...
Earth resistance value may be a bit out of the max specification.
 
8bits said:
QueenBee said:
8bits said:
as I told, the original from my car doesn't work and so I will need to "disable" some safety, probably the earth resistance measure
Click to expand...

Did your electrician have any ideas on why your garages electrical system is different than normal and thus why the EVSE enters a fault state?
Click to expand...
Earth resistance value may be a bit out of the max specification.
Click to expand...

I think an easier approach might be outlined here: http://www.mynissanleaf.com/viewtopic.php?p=205127#p205127" onclick="window.open(this.href);return false;

Please note that I do not have the proper knowledge nor information about your situation to determine if this is a safe solution for you so please ensure that you've consulted someone familiar with your situation and who has the experience to properly determine the safety.
 
QueenBee said:
I think an easier approach might be outlined here: http://www.mynissanleaf.com/viewtopic.php?p=205127#p205127" onclick="window.open(this.href);return false;

Please note that I do not have the proper knowledge nor information about your situation to determine if this is a safe solution for you so please ensure that you've consulted someone familiar with your situation and who has the experience to properly determine the safety.
Click to expand...
THANKS!! I will explore this option.
 
My EVSE, of my Smart electric car still doesn't work. I designed the NE555 circuit so I can visualize how I will prototype it. I also used LTSpice to simulate and it seems to have the output I am looking for - ~5us --> ~8A current charge.

evse.png


evse_simul.png
 
8bits said:
My EVSE, of my Smart electric car still doesn't work. I designed the NE555 circuit so I can visualize how I will prototype it. I also used LTSpice to simulate and it seems to have the output I am looking for - ~5us --> ~8A current charge.
Click to expand...
Your Smart EV is probably smart enough not to work with this circuit. The LEAF really shouldn't. This design cuts many, many corners and I would expect if to fail with a lot of EVs.
 
8bits said:
Also latest OpenEVSE is BIG, uses an LCD that I would not use most of the time - I am looking for someting very small (just as you did) and that works with the same current - maybe no more than some little switchs to choose from 4 different current values.
Click to expand...

This marks the first time I have been told the current OpenEVSE board is BIG (and in all caps)... at 2.2"x 1.75"x 3/4" it includes an integrated Power Supply most comment on how tiny it is. I do not think much can be done to make it smaller while maintaining all the important J1772 safety features (GFCI, Ground check, Stuck Relay detection, etc.)

The LCD is also optional, it works great without a display.
 
davewill said:
Your Smart EV is probably smart enough not to work with this circuit. The LEAF really shouldn't. This design cuts many, many corners and I would expect if to fail with a lot of EVs.
Click to expand...
What do you think is the minimum for an EVSE work on a car like mine?

I must say I prototyped that small and simple circuit and I couldn't get any wave out of it :-( :-( --- maybe I will go with a microcontroller...
 
chris1howell said:
8bits said:
Also latest OpenEVSE is BIG, uses an LCD that I would not use most of the time - I am looking for someting very small (just as you did) and that works with the same current - maybe no more than some little switchs to choose from 4 different current values.
Click to expand...

This marks the first time I have been told the current OpenEVSE board is BIG (and in all caps)... at 2.2"x 1.75"x 3/4" it includes an integrated Power Supply most comment on how tiny it is. I do not think much can be done to make it smaller while maintaining all the important J1772 safety features (GFCI, Ground check, Stuck Relay detection, etc.)

The LCD is also optional, it works great without a display.
Click to expand...
Hello chris1howell!!

Thank you for all of your work in OpenSource! - your work inspires me, thanks.

I would like to get an "EVSE" small enough and cheap, to fit into a J1772 plug, just like BareEVSE. Also I am not looking for the safety features - thanks to them, the original EVSE that came with my car doesn't work. My electric circuit is ok and have protections.

I wish I could buy OpenEVSE assembled and tested, and get it at my home in 5 days.
 

Similar threads

M
Gaining remote-control of the windows
Replies
0
Views
388
macgeeknz
M
knightmb
Leaf Service EV System Adventures with P0AA6-1A and a Suspect 12V Battery
3 4 5
Replies
80
Views
4K
CaptLarry
C
D
Emporia EVSE
Replies
4
Views
5K
Daklein
D
E
Heater Failed 2011 Gen 1
Replies
6
Views
1K
BillAinCT
B
E
OBC no output power - L1 charging
Replies
6
Views
2K
evanagon
E

Latest posts

Back
Top