My L1 ESVE findings.....

[chris1howell]

Good work ... so my first theory was mostly correct about the small relay. The 120v tvs diodes would be fine if they go to ground. As either Hot to ground is only 120v. If they tie the hots together in the case of 240 they need to be replaced...

[lincomatic]

Alright guys, so the 2 main relays are controlled by transistors and the third smaller relay places a 4.26~ k ohm resistance between hot and neutral on the output of the 2 main relays. So it closes the mains and checks the current path or it would be looking for a voltage source (lack there of really) before closing the mains. What's interesting is the it takes the hot leg prior to the gfi CT and the neutral leg after the CT. So it's using the CT to check for a current path. 120vac and 4.27 k the CT should read around 28 mA.

I wonder why it needs to look for a current between hot/neutral instead of hot/gnd? GFI self trip test?
So we still don't know how it's checking the ground integrity.

BTW, do you have a part number for the microcontroller it's using?

[Ingineer]

The small relay is used for the Ground Fault prove out. This simulates an unbalanced current situation which tests the CT and GF circuitry. The failure mode for most GF circuits is the CT or the buffer/detect circuitry, so without prove-out, you would be risking the dangerous situation where the GF detection could fail and still allow the EVSE to energize the load.

They also perform a relay "stuck" test to detect if one or the other relays have welded contacts, and if so, the opposing relay will be de-energized. The ground verification test passes a small current through ground to verify a low impedance path.

This is why all your simple bypasses and re-routes failed, and if you bypass or fake any of the prove-outs, you are creating a dangerous situation. So again I will stress that you should not explore this path.

You will find, as I did, there is no $20 path to convert this EVSE to 240v operation, let alone a SAFE method. It can be done relatively easily with the right methods, but by the time you add up all the costs, you will find it well outside of your $20.

I spent several weeks reverse-engineering the circuitry and firmware so I could write a new version to enable the 16A pilot. Any other way will require addition of a lot of extra circuitry most likely including another microcontroller. By the time you do all this you will probably have spent 100 man-hours and at least $50 in parts. In any event, not an upgrade recommended for the hobbyist.

Then if you hope to sell your upgrades, by the time you pay your insurance, answer all the emails and phones, and all the other overhead, you will find there is not much to be made. I hope to be out of the upgrade business as soon as there are enough EV's on the road to warrant a business case to make a better EVSE for lower cost. The main thing I've gained from EVSEupgrade is less sleep.

I've been supporting the EV movement for almost 20 years, and I saw the availability of a low-cost solution for charging the LEAF as a stumbling block that may impact it's success, so this was my motivation for going down the upgrade path, something normally considered silly. I thought about "open-sourcing" my design, but if just one person got hurt because someone did something wrong, it would all be for nothing, and I'm not sure I'd want to live with that. If you are competent enough to modify your own EVSE, then it's pretty obvious how to do it, but I am not going to be irresponsible and release details to the general public on how to do so which could easily encourage someone to do something dangerous.

Keep in mind if you encourage people to do just that and someone gets hurt or killed attempting to follow your instructions, YOU could be sued and held liable for the death or injury.

-Phil

[LEAFfan]

Then if you hope to sell your upgrades, by the time you pay your insurance, answer all the emails and phones, and all the other overhead, you will find there is not much to be made.
-Phil

I really don't believe Jack was doing this to make any money. I feel he was just trying to help us with a less expensive alternative. I just wanted something that I could use IF my Blink went on the blink. I doubt if I would use it for anything else, plus I may have to give my Nissan EVSE back after the lease if I decide not to buy so I would like a temporary fix if possible. I think yours is great for someone who doesn't have a 240V charging station and isn't leasing. One forum member I know made his Nissan EVSE 120/240V for only $90, and he said it still had all the safety features, but I don't know how or what he did to it.

[downeykp]

Phil, I am very appreciative of the fact that for under $300 I was able to have a true level 2 charger. Your product saved me over $1700 over what AV wanted. Your product is great and works flawlessly. Mahalo.

[Ingineer]

I really don't believe Jack was doing this to make any money. I feel he was just trying to help us with a less expensive alternative. I just wanted something that I could use IF my Blink went on the blink. I doubt if I would use it for anything else, plus I may have to give my Nissan EVSE back after the lease if I decide not to buy so I would like a temporary fix if possible. I think yours is great for someone who doesn't have a 240V charging station and isn't leasing. One forum member I know made his Nissan EVSE 120/240V for only $90, and he said it still had all the safety features, but I don't know how or what he did to it.

I support anyone making money for their efforts, the reason I posed that bit, is because a few people called my comments "greed induced", which is definitely not the case.

Plenty of our customers are leasing. We offer a free exchange with a unmodified unit at the end of your lease, and also, almost anyone with a new LEAF would be happy to swap you. Hell, you can probably sell it, buy a new one at the Nissan parts counter, and even make a few $.

There is no way you can easily modify the EVSE, then return it to stock. For starters, there are the plastic plugs they use to seal the unit. You cannot extract those intact and put them back. Any dealer will be able to instantly tell you took the unit apart, even if you get it completely back to stock otherwise. Once you have depotted your PCB and soldered on it, you definitely aren't getting it back to stock. If you just make it "look" stock, and the dealer sells the car to a used car customer with your hacked up unit in there, and something goes wrong, guess where the detectives will end up?

-P

[Ingineer]

Phil, I am very appreciative of the fact that for under $300 I was able to have a true level 2 charger. Your product saved me over $1700 over what AV wanted. Your product is great and works flawlessly. Mahalo.

Thanks!

Sorry if I'm ranting about this, I just wanted to be crystal clear that attempting modifications, especially ones that defeat any safety circuits, should not be undertaken by unqualified people.

Also, having an engineering degree does not automatically make you qualified, if you have no experience with current practices in this field. For instance, claiming that an upstream 240v outlet has "protection" is false. It's almost never the case where an existing 240v outlet (and most that are added) are protected by a GFCI as Jack claims. In any event, his hack would instantly trip it if it were to exist, as it is returning all the EVSE internal load to neutral.

It's obvious to me (And anyone else reading this) that Jack didn't even understand how the GFCI functioned, and what it's purpose was. Thankfully Chris pointed it out to him. How hard is it to research things like this before you begin trying to alter a design that incorporates one?

Jack, please read this article.

-P

[jwallace3]

Look dude, if you don't like what I have to say, don't read. Just because I'm reverse engineering the charger after you had and I'm telling what I fond for scrutiny and brainstorming doesn't mean you have to act like I'm an idiot. That is a scientists way. You find something you put it out there for minds to pick apart, ask questions, and solve problems. I've done nothing but say you have a good product and I'm not trying to replace you or what you're doing, I'm not trying to make money either. I make plenty of that at my real job. I know what a gfi is and how it works. I know AC power like the bsk of my hand, that's my specialty homie. Microprocessors and signals were my emphasis in college, I may not have my PE in that area of expertise but I'm still actively engaged with my university's engineering department and consult for fun on many projects in many areas. I built a damn rov submersible as a junior. That's putting electronics into water under high pressure. You don't think I can figure out an extension cord that has brains and offer safe instructions to mod, if I do in fact discover that there is a simple mod? Notice I haven't given any instructions yet on how to do anything and yet all you have to offer to my early research is "don't listen to this guy", "just because you have an engineering degree doesnt make you qualified". What is your area of expertise if I might ask? Do you have your PE? Is it in power, electronics? What? I make desings every day for people working on extremely high voltages, currents, and ultimately power. And I do it safely and peoples' lights stay on and are more reliable because of what I do in smart grid. As far as my "by pass circuit" as you call it, it didnt bypass anything. I introduced a 3rd relay to deal with the second phase of 120, which I'm still convinced should work just fine. The ground check is not the reason it didn't work at first glance, I always had a path from hot to ground and from hit to neutral. The factory path was never disturbed. I was simply adding another relay to route the second 120 phase through the gfi CT an out to the charger if the 240 second leg was present. I Wilkins find my solution and I will tell all the results, if it's not possible to do as I'm proposing with a third relay and keeping all the safety featured in tact I'll say it. For now, I'm reverse engineering to see if I'm missi anything and while I have it out and depotted I'll answer the many questions people have about parts and how it works. I'm glad you're doing what you're doing and I like your product. If we didn't ever ask the same question twice we would never advance in science . Sorry I'm that guy asking the question again. If you had posted all you knowledge you gained from reverse engineering before me and code and schematics I probalbly wouldnt be doing this. I'd be using what you put out there to do whatever it was I was trying to do. For now though this thread is for my results, findings, for people to ask questions about the circuits, and for me to answer them, and if I come to the result of having a inexpensive safe alternative I'll post plans and instructions. Until then unless you have something constructive you're willing to share, back off please.

[GeekEV]

Might all this angst be resolved with a simple title change of this thread? The current title seems to imply a viable product for $20 when that's not really what you're saying. May I suggest "experiments on the Panasonic trickle charger trying to enable cheap DIY L2"?

[jwallace3]

And just for the record, I was a second away from buying your upgrade when it occurred to me, why can't I find a solution myself? I have plenty of resources at home and I have all the university equipment at my disposal. This isn't just for me, I'm letting anyone who wants to know what I find and this is upfront knowledge for my students who are developing a portable ESVE for their senior project. After all it's better to learn from what others have done. Isn't that what engineering is about, solving problems or coming up with a better solution? That's wha IEEE is about, sharing ideas and getting constructive criticism. And why from one engineer to another are you dogging me on a problem I have yet to begin to solve? I thought I had a simple solution, and I'm still convinced I do. It was probably a silly mistake I made in my routing of current through the CT so the net current was zero. And yes, it occurred to me after my post about the third relay last night that it was probably a CT check for the gfi. I didnt design the circuit so I have no idea what the engineers were thinking. I have no code with comments to look through to find out what their internal process was for the ESVE. After all, it is an engineer's nature to ask questions and look for a solution or a better solution. Hell we just learned that particles at CERN traveled faster than the speed of light, pending they repeat the experiment, but the put theyre results out there and are looking for ideas as to how this could have happened. After all if they're right Einstein was wrong. Einstein didn't have the tools to accelerate sub-atomic particles to what they thought would be less than the speed of light. But that is what experimentation is about, learning and proving and disproving your ideas. I'm not Einstein, but if i prove my idea I'll have results. If I'm wrong, I'll say my idea is not a viable option.