jwallace3
Posts: 156
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Leaf Number: 6014
Location: Tennessee

My L1 ESVE findings.....

Sat Sep 17, 2011 9:33 am

I'm an electrical engineer and have been looking for a cheap easy way to mod the panasonic esve that comes with the leaf to allow for L1 or L2 charging. Mainly so I can visit my parents down in Columbia, TN and I live in Springfield, TN which is about 64 miles each way. Anyway, I successfully made a small wiring mod last night which consisted of me changing out the 120 volt pigtail to a 240 pigtail I made and running a jumper on the inside of the unit. This will allow me to put it all back to the original setup if I need to for some other reason. Utilizing another pigtail which plugs into my new pigtail I mounted the unit I can also charge legacy L1. The entire circuit board is sealed in a rubber like potting material so I'm trying not to disturb that if possible. I will be working on a little better way to complete the 240/120 mod since the way I have it right now disables some of the safety features of the unit. I did charge successfully from 3 bars to 12 last night in 7 hours so a little slower than the 16 amp charging which would have taken about 5 or so. I will also be working on an easy way to extend the pulse width of the 1kHz square wave to allow for full 16 amp charging instead of the 12 amp that I'm currently charging at. Since I'm not modifying the existing electronics, I will probably be using a small micro to do an input capture of the pulse and extend the pulse with my micro. Space is the main constraint so it will have to be a small micro with that functionality. So just a heads up for those interested I will be posting my final results once I clean up the process and have good pics with instructions. Also as a heads up I'm currently working with my alma mater (Western Kentucky University) engineering department and am advising on a senior project to develop a portable, inexpensive 120/240 esve with 12-20 amp functionality. After the prototype is perfected they will be manufacturing some units for sale on a case by case basis. We expect the final cost to be betweek $400-$800 depenedent completely upon how inexpensive we can find the J1772 connector from a manufacturer. Please email or PM with any questions.
Jack
Last edited by jwallace3 on Fri Sep 23, 2011 9:09 pm, edited 1 time in total.
Reserved: 9/22/10
ESVE (EV Project) Approved: 3/24/11
RAQ: 3/28/11
Ordered: 3/29/11
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Delivery: 8/4 -> 8/5 -> 8/11 -> 8/4 ->8/5 -> 8/3
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jwallace3
Posts: 156
Joined: Thu Apr 28, 2011 9:35 am
Delivery Date: 01 Aug 2011
Leaf Number: 6014
Location: Tennessee

Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 10:08 am

If anyone knows where I can locate a schematic for this unit the mod would take a less time and I would be able to implement all safety features except for current leakage detection. That would only be available @ 120 charging. This is because they have a CT with the 120 hot and neutral passing though it. At 120 the current must return so the sum of the currents passing through the CT will be zero unless there is a current leakage somewhere. At 240 , however, there is no return path. All of the current is consumed by the charger so this CT method doesnt work and would have to be disabled durning 240 charging.

Edit: This statement is completely wrong. I was tired and had a crying 4 month old when I wrote this. Obviously not thinking. Please ignore.
Last edited by jwallace3 on Sun Sep 18, 2011 11:01 am, edited 1 time in total.
Reserved: 9/22/10
ESVE (EV Project) Approved: 3/24/11
RAQ: 3/28/11
Ordered: 3/29/11
Blink Install: 7/20/11
Delivery: 8/4 -> 8/5 -> 8/11 -> 8/4 ->8/5 -> 8/3
Took delivery 8/6/11 Super Black SL-e
VIN: 6014

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TomT
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Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 10:13 am

You do realize, I assume, that Ingineer did this conversion quite some months ago - while maintaining all of the safety features - and has been selling a 120/240 variable current upgrade for the Panasonic ever since... For what little he charges, it hardly seems worthwhile reinventing the wheel.
jwallace3 wrote:I'm an electrical engineer and have been looking for a cheap easy way to mod the panasonic esve that comes with the leaf to allow for L1 or L2 charging. Mainly so I can visit my parents down in Columbia, TN and I live in Springfield, TN which is about 64 miles each way. Anyway, I successfully made a small wiring mod last night which consisted of me changing out the 120 volt pigtail to a 240 pigtail I made and running a jumper on the inside of the unit. This will allow me to put it all back to the original setup if I need to for some other reason. Utilizing another pigtail which plugs into my new pigtail I mounted the unit I can also charge legacy L1. The entire circuit board is sealed in a rubber like potting material so I'm trying not to disturb that if possible. I will be working on a little better way to complete the 240/120 mod since the way I have it right now disables some of the safety features of the unit. I did charge successfully from 3 bars to 12 last night in 7 hours so a little slower than the 16 amp charging which would have taken about 5 or so. I will also be working on an easy way to extend the pulse width of the 1kHz square wave to allow for full 16 amp charging instead of the 12 amp that I'm currently charging at. Since I'm not modifying the existing electronics, I will probably be using a small micro to do an input capture of the pulse and extend the pulse with my micro. Space is the main constraint so it will have to be a small micro with that functionality. So just a heads up for those interested I will be posting my final results once I clean up the process and have good pics with instructions.
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jwallace3
Posts: 156
Joined: Thu Apr 28, 2011 9:35 am
Delivery Date: 01 Aug 2011
Leaf Number: 6014
Location: Tennessee

Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 10:22 am

I do. I just didn't feel like paying $240+ for this conversion when I can do it for $20. Plus being an electrical engineer, I just wanted to see how they did it and make the mod myself. Just like when I built an electric 36 volt 4 wheeler for my daughter, instead of buying a motor controller, I designed my own and had the board cut and components mounted by my friends at the university who have surface mount capability. It's just part of my curiosity and creativity and the info that I will post is for the rest who are like me who just want to do it themselves for the challenge. Also, my mod doesn't change any internal components or firmware. I am adding components to the existing package, so one could in theory remove those extra componets and return the internals to the factory setup and re-seal. Technically opening the unit voids your warranty, however, they wouldu never be able to tell that the unit was every modded with my method if you re-seal the unit properly.
TomT wrote:You do realize, I assume, that Ingineer did this conversion quite some months ago - while maintaining all of the safety features - and has been selling a 120/240 variable current upgrade for the Panasonic ever since... For what little he charges, it hardly seems worthwhile reinventing the wheel.
jwallace3 wrote:I'm an electrical engineer and have been looking for a cheap easy way to mod the panasonic esve that comes with the leaf to allow for L1 or L2 charging. Mainly so I can visit my parents down in Columbia, TN and I live in Springfield, TN which is about 64 miles each way. Anyway, I successfully made a small wiring mod last night which consisted of me changing out the 120 volt pigtail to a 240 pigtail I made and running a jumper on the inside of the unit. This will allow me to put it all back to the original setup if I need to for some other reason. Utilizing another pigtail which plugs into my new pigtail I mounted the unit I can also charge legacy L1. The entire circuit board is sealed in a rubber like potting material so I'm trying not to disturb that if possible. I will be working on a little better way to complete the 240/120 mod since the way I have it right now disables some of the safety features of the unit. I did charge successfully from 3 bars to 12 last night in 7 hours so a little slower than the 16 amp charging which would have taken about 5 or so. I will also be working on an easy way to extend the pulse width of the 1kHz square wave to allow for full 16 amp charging instead of the 12 amp that I'm currently charging at. Since I'm not modifying the existing electronics, I will probably be using a small micro to do an input capture of the pulse and extend the pulse with my micro. Space is the main constraint so it will have to be a small micro with that functionality. So just a heads up for those interested I will be posting my final results once I clean up the process and have good pics with instructions.
Last edited by jwallace3 on Sat Sep 17, 2011 10:41 am, edited 1 time in total.
Reserved: 9/22/10
ESVE (EV Project) Approved: 3/24/11
RAQ: 3/28/11
Ordered: 3/29/11
Blink Install: 7/20/11
Delivery: 8/4 -> 8/5 -> 8/11 -> 8/4 ->8/5 -> 8/3
Took delivery 8/6/11 Super Black SL-e
VIN: 6014

tps
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Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 10:39 am

jwallace3 wrote:I would be able to implement all safety features except for current leakage detection. That would only be available @ 120 charging. This is because they have a CT with the 120 hot and neutral passing though it. At 120 the current must return so the sum of the currents passing through the CT will be zero unless there is a current leakage somewhere. At 240 , however, there is no return path.
Not sure I understand this... Why wouldn't there be a return path at 240V; doesn't "no return path"=="open circuit"? Why wouldn't all the current flowing out on pole return through the other pole, thus creating a sum of zero at the CT regardless of the voltage. The fact that one pole is neutral at 120V while that same pole is another hot at 240V should make no difference. Current which goes somewhere else but flow through the two wires is by definition leakage, no?

jwallace3
Posts: 156
Joined: Thu Apr 28, 2011 9:35 am
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Location: Tennessee

Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 11:16 am

Yes,
this should be the case, however, the charger doesn't like single phase 240 going through the CT. It thinks there is a current leak. I am still working out the issues. Breaking out my power book. It's been a while, I am a power engineer, so I'm used to dealing with 3 phase. Single phase is different because 240 is single phase with a center tap on the secondary. I
tps wrote:
jwallace3 wrote:I would be able to implement all safety features except for current leakage detection. That would only be available @ 120 charging. This is because they have a CT with the 120 hot and neutral passing though it. At 120 the current must return so the sum of the currents passing through the CT will be zero unless there is a current leakage somewhere. At 240 , however, there is no return path.
Not sure I understand this... Why wouldn't there be a return path at 240V; doesn't "no return path"=="open circuit"? Why wouldn't all the current flowing out on pole return through the other pole, thus creating a sum of zero at the CT regardless of the voltage. The fact that one pole is neutral at 120V while that same pole is another hot at 240V should make no difference. Current which goes somewhere else but flow through the two wires is by definition leakage, no?
Reserved: 9/22/10
ESVE (EV Project) Approved: 3/24/11
RAQ: 3/28/11
Ordered: 3/29/11
Blink Install: 7/20/11
Delivery: 8/4 -> 8/5 -> 8/11 -> 8/4 ->8/5 -> 8/3
Took delivery 8/6/11 Super Black SL-e
VIN: 6014

jwallace3
Posts: 156
Joined: Thu Apr 28, 2011 9:35 am
Delivery Date: 01 Aug 2011
Leaf Number: 6014
Location: Tennessee

Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 11:37 am

There is one safety feature that I'm not sure how it can be implemented at 240. The panasonic ESVE checks to see if ground and neutral are tied together to tell the unit that the circuit is properly grounded. At 120 the existing cable has hot, neutral, and ground. If you look at any 240 charger there is still only 3 wires hot 1, hot 2, and ground. So if you modify the panasonic ESVE for 240 charging there is absolutely no way with 3 wires that this feature can be implemented because the charger would be checking to see if the previous neutral terminal (now hot/phase 2) is tied to ground. This would be a bolted fault which would trip the breaker in your panel. So this feature has to be bypassed unless you add a third relay and use a 4 wire nema 14 connector to accomplish this. But with a 3 wire nema 6 it's just not possible. I am just doing this for fun at the moment. Its actually a lot easier to just build a whole new charger. I have the SAE J1772 standard I could probably build a 120/240 universal charger prototype in a day if I had the relays I need on hand. I am letting the students at Western build one because its a good engineering exercise to design based off of a standard. I will probably go ahead and build one myself and use my current J1772 connector from my panasonic ESVE. I typically use freescale microprocessors for projects like this since it has plenty of features and is relatively cheap, but the logic required for the J1772 standard is so simple I may just use a picaxe or something of that nature. Also, the panasonic ESVE uses a transformer and bridge rectifier for the electronics DC. This is kind of an outdated method. A rectifier and swithing power supply with a closed loop control system is the cheapest way to go plus it can adapt to any input AC voltage in the design window, ie 120-240 vac. This is probably the way I will go.
Reserved: 9/22/10
ESVE (EV Project) Approved: 3/24/11
RAQ: 3/28/11
Ordered: 3/29/11
Blink Install: 7/20/11
Delivery: 8/4 -> 8/5 -> 8/11 -> 8/4 ->8/5 -> 8/3
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mitch672
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Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 12:16 pm

You can buy a controller already, and add the contactor, power supply, J-1772 cable and case... http://modularevpower.com/EVSE_module_3.htm" onclick="window.open(this.href);return false;

Of course thats probably more than you want to spend for the controller.

At this point, there are the Aerovironment units on eBay for $599, the Schnieder is at Home Depot for $729, the SPX PowerExpress (which has an adjustable Pilot signal, 12A/16A/24A/32A) is $749.

I don't think its worthwhile from a cost perspective any longer. If you want to to it for other reasons, thats fine, but you're not going to save much money building your own EVSE, once you factor in your labor.
Last edited by mitch672 on Sat Sep 17, 2011 1:13 pm, edited 1 time in total.
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Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 1:01 pm

jwallace3 wrote:I'm an electrical engineer and have been looking for a cheap easy way to mod the panasonic esve that comes with the leaf to allow for L1 or L2 charging.
Jack
Good deal Jack. One thing I don't hear anyone talking about is the EVSE temperature after some period of charging. Last night I took my Ingineer modified, 240v, 12a Panasonic EVSE and decided to charge my car from 1 bar to 12 bars at about 75% of the Blink charge rate. I did this test because I just had my car software upgraded (from a 1-4-11 purchase date) and I was hoping to reset the range-o-meter (with no practical reason to justify why it might do so) since I usually charge to 80% every day and only charge to 100% once per month.

I must say I'm very disappointed in the software upgrade. The range-o-meter AND the bars indicate I can't go as far as I've been going on a charge (the range-o-meter lost 1 bar and 6 miles from what I had been getting - oh the pendulum always swings too far when you get a rash of complaints on anything it seems).

Anyway, the temperature of the bottom of the EVSE sitting on a towel got to 129 deg F within two hours of charge start (240v, 12a) and had risen to 136 deg F at the end of the 6 hour charge cycle. That's measured on the outside of the package! I was thinking about upping the EVSE to 16a with Phil's additional upgrade but now I'm concerned about the temperature of the unit if I do so. At this point I need to test it at 120v, 12a to see what temp it gets to but I was surprised it got so high. This says the losses in the unit are greater than I expected. Hmmm...

Malcolm :geek:

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GeekEV
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Re: $20 Panasonic trickle charge mod allows 240VAC @ 12 amps

Sat Sep 17, 2011 1:55 pm

Yes, the firmware upgrade takes some off the top but gives it back to you at the bottom end int the form of a hidden "reserve". When you get low and it says you've got about 8 miles left, it's really more like 15.

As for temperature of the modified EVSE, Ingineer's done fairly extensive torture testing at significantly higher than 16a. It doesn't get much hotter than that. Lots of us have done it, you'll be fine.

I'm no electrical engineer, but this talk of jumpering things seems strange. Ingineer actually depotted the entire board and found it was all ready for 240v except for a couple components that were rated at 120v. How can you do this without replacing those components or running them way over spec (which doesn't seem safe)? Anyhow, you're free to do whatever you want with your own unit, of course. ;)

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