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Finally finished up the conversion to Open EVSE of my dead Voltec 240V EVSE:



Viewing two threads in particular, this one by Steverino and this one by Neromanceres, I decided to go ahead and tackle this project.

I ordered the individual parts from the OpenEVSE Store for the 30A DIY kit, except the case and J1772 cable, since I reused those from my Voltec.

Like Neromanceres, I used clear Lexan for the base to mount the components, and used nylon insert nuts to hold things tight. I even used the wire from the old Voltec board when I wired up the new components, which explains why the wire color on the left input side isn't exactly correct. :p



To make the flashlight work:



I used a 680 ohm resistor (thanks, Neromanceres!) going from the 12V DC Relay Common connection on the OpenEVSE board, as there is always 12V DC there:



You could also power the two green front panel LEDs from there, and they would stay on as long as there was power to the EVSE.

I wanted to try incorporating the RGB LCD display and Menu/Select button from the DIY kit, so I had to make some holes in the front cover:



I ended up cutting the Voltec front panel 2 LED board just below the original connector to make it fit, and I powered the LEDs from the nearby 5V DC pad above the four wire LCD connector (the one black wire and heat shrinked 100 ohm resistor going up to the top of the LED board). After cutting the LED board down to size, I just soldered wires directly to the LEDs so they would light up.

I had to lengthen the four wire LCD to OpenEVSE board cable to make it reach the front cover, and allow the cover to be easily attached.

I cut a second piece of Lexan to mount the LCD board to the front panel, and to protect the LCD screen. I then used epoxy around the perimeter of the Lexan and glued it to the back of the front panel.

The LCD display shows the charger status, and the backlight color for the LCD display changes color depending on status. It will also tell me if one of the safety checks fails, which will make any troubleshooting easier.



The status, current being used by the Volt, total watt-hours for the current charge session, and total kilowatt-hours on the charger are shown here.

Happy Charging!
 

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Very nice job! Neat and orderly. Well done
 

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Yes, very nicely done.

My second L2 Voltec recently failed as well (completely dead); I found it has a blown fuse and replaced it, but haven't had a chance to see if it works now (I had a spare OpenEVSE charge station, so wasn't in a hurry). I'm second-guessing my decision to replace the fuse; I might try to convert it to OpenEVSE as I did the first one, but use your display mounting technique.
 

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Well done! As an EE and having built my own EVSE (see my post in the forums), I see that your construction was a great job. The use of a Lexan base plate makes planning the layout better as it adds surface area with insulation, and mounting all the components easier. Remember that each wire crimp add two weak points in a circuit, so those crimps must be very tight, crushing the strands to get the best contact with the least resistance. For anyone using #8 or greater gage (I did for my 16 kW rated EVSE), you must use a heavy tool to get the best crimps, and use the best screw-on connections possible without stripping the threads.
 

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Good work. I will have an option for my 2 and a half year old Voltec when the time comes.
The Star Trek styling of the Voltec L2 may be it's only redeeming quality. As you said the 30 amp box inside doesn't make it totally capable of 30 amp charging. Those white nylon terminal strips are an unfortunate carry-over. Flimsy. Is that #10 feeding the L2? It won't take #8. It doesn't show but the ribbon feeding the lights is still there? Ribbon fell out on my Voltec.
Most people would want to do this to reuse the J cord (the most expensive part). The rubber cord is the weak link in all EVSEs. Replacing them should become a cottage industry in the future. There has been a post about taking apart the Voltec plug. Exposed screws would be better. The rubber cord can be bought at Home Depot and customized in length. That Voltec coiled cord is a monstrosity. You can't stretch it to half it's length without an unacceptable strain on the ends. In particular, the strain on the receptacle in your car (the one thing you don't want to wreck).
It's a project I might consider but I don't think I will be saving money.
 

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...

That Voltec coiled cord is a monstrosity. You can't stretch it to half it's length without an unacceptable strain on the ends. In particular, the strain on the receptacle in your car (the one thing you don't want to wreck).
...
The very reason I went with a Nissan branded AeroVironment EVSE back when they were surplussed due to over-charging electricians in the early days of the Leaf. I recently loaned it out to my brother for his Spark, after getting the free Bosch for our Spark. My Volt is happy with a 10A OpenEVSE that uses the original 16 AWG 120V Voltec cable. If either one fails, I will be replacing the innards with OpenEVSE, it's good to see some examples of how it's done.
 

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Discussion Starter #9
Thanks everyone for the replies.



Still going strong! This is the display after a charging session completes.

Very nice job! Neat and orderly. Well done
What a quick reply, Steverino! Thank you for the compliment.

Yes, very nicely done.

My second L2 Voltec recently failed as well (completely dead); I found it has a blown fuse and replaced it, but haven't had a chance to see if it works now (I had a spare OpenEVSE charge station, so wasn't in a hurry). I'm second-guessing my decision to replace the fuse; I might try to convert it to OpenEVSE as I did the first one, but use your display mounting technique.
The first thing I did was check the fuses and MOVs for failure. Both tested okay, so I figured it must be the switching power supply. The choice to convert to OpenEVSE was easy after that.

Well done! As an EE and having built my own EVSE (see my post in the forums), I see that your construction was a great job. The use of a Lexan base plate makes planning the layout better as it adds surface area with insulation, and mounting all the components easier. Remember that each wire crimp add two weak points in a circuit, so those crimps must be very tight, crushing the strands to get the best contact with the least resistance. For anyone using #8 or greater gage (I did for my 16 kW rated EVSE), you must use a heavy tool to get the best crimps, and use the best screw-on connections possible without stripping the threads.
Thanks, Raymond. I do like how your EVSE turned out, just wish you could be using it!

As for the crimp connections, I do have a fairly heavy crimp tool that I've used for years when working on the wiring of full size arcade pinball machines from the 1990's. They used plastic or nylon IDCs (Insulation Displacement Connectors) for the lighting in the backbox (where the score is) and over time, the connectors could burn due to not enough surface area making contact for the load. Replacing those IDCs with crimp connectors fixed that problem, so I made sure the crimps in my EVSE were good and tight, as were the screw terminals. I only plan on using my fixed Voltec with my Volt, so I've set it to a maximum of 16A, and I've only ever seen my Volt pull a maximum of 14A while charging in my 93 degree F ambient attached garage here in Texas. I leave the garage door cracked open to let some of that heat out while charging at that temperature!

Good work. I will have an option for my 2 and a half year old Voltec when the time comes.
The Star Trek styling of the Voltec L2 may be it's only redeeming quality. As you said the 30 amp box inside doesn't make it totally capable of 30 amp charging. Those white nylon terminal strips are an unfortunate carry-over. Flimsy. Is that #10 feeding the L2? It won't take #8. It doesn't show but the ribbon feeding the lights is still there? Ribbon fell out on my Voltec.
Most people would want to do this to reuse the J cord (the most expensive part). The rubber cord is the weak link in all EVSEs. Replacing them should become a cottage industry in the future. There has been a post about taking apart the Voltec plug. Exposed screws would be better. The rubber cord can be bought at Home Depot and customized in length. That Voltec coiled cord is a monstrosity. You can't stretch it to half it's length without an unacceptable strain on the ends. In particular, the strain on the receptacle in your car (the one thing you don't want to wreck).
It's a project I might consider but I don't think I will be saving money.
Atomic, the OpenEVSE Plus 2.5 is capable of 30A (24A continuous) charging when using heavy enough gauge wire and a properly wired circuit. It can also auto detect between 240V and 120V connections. As I'm only charging my Volt with it, I set the current limit to 16A, as it is connected at the breaker box to 20A breakers.
I don't recall if I used #10 or #12 solid copper wire to power it. The breaker box is on the same wall as my Voltec, so the run is pretty short.
I ended up not using the ribbon cable from the Voltec. At one point I was going to use it as the disconnect for the front panel, but that wasn't necessary after I cut the PCB holding the two LEDs down to size.
The rubber strain relief on the car side of the cord cracked long ago, so I have it zip-tied together. The coiled cord is quite heavy, but it can stretch quite far, and the flashlight is handy.
You're right - this project doesn't really save money (it would've been cheaper to not get the push button and display, or pay extra for the "built" components from the OpenEVSE store), but it was still a fun project to build. Hopefully, if anything wears out, I can just order the pieces I need instead of another entire EVSE. Time will tell.

Awesome!!!
Thanks, Noel. I take it your busted Voltec went to a good home?

Wow that looks really good. Makes me want to possibly go back and modify mine with the current sensor, button and LCD display.
The cutout for the LCD screen was definitely the hardest part. It was done freehand, and I had to file it afterwards to make it somewhat straight. Not the easiest piece to cut straight lines in!

Also gave me an excuse to buy a new jig saw... ;)
 

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I have a busted Voltec and did a quick replace with a Clipper Creek. I have been considering do much the same as you did with it. Surprisingly the second Voltec I have is still operational after 3.5 years (knock on wood).
 

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I have a busted Voltec and did a quick replace with a Clipper Creek. I have been considering do much the same as you did with it. Surprisingly the second Voltec I have is still operational after 3.5 years (knock on wood).
I figure I got about 4 years use out of mine, which is better than the average around here.

After checking fuses and seeing what this guy found wrong on another 240V Voltec:

http://blog.coppelltvrepair.com/2014/05/repairing-chevy-volt-charging-station.html?m=1

The decision to go OpenEVSE was easy.
 
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