Power Trip
(Click to enlarge)
Upgraded Onboard EVSE
for my Nissan Leaf

April 8, 2012

Mark D Larsen

Let me make one thing clear clear right up front: electricity can kill you. It seems prudent to remind others of that danger from the outset, since there are so many candidates ripe for a Darwin Award in this world.

With that disclaimer, let me say that I’ve never understood the paranoia about charging electric vehicles among those who work for the UL (Underwriters Laboratory), the NEC (National Electrical Code), or the SAE (Society of Automative Engineers). In countries like New Zealand, Australia, all of Europe, drivers can simply plug their electric vehicles into standard 240V outlets. Yet in this country those organizations have fought against it, insisting instead that EVSEs should be permanently hardwired into the electrical supply. Even more inexplicable, however, is the double standard that those organizations apply to RV parks and marinas, where they do allow people to use 240V plugs and outlets each and every day. Are campers, boaters, Europeans, Australians, New Zealanders simply smarter than average American drivers? I seriously doubt it. It is therefore inevitable that, as the number of EVs proliferate on our roads, those drivers will likewise want to be able to plug their vehicles into 240V outlets, if for nothing else that to charge their battery packs at those same RV parks and marinas.

The Nissan Leaf comes with a “trickle” EVSE cordset onboard, so that, in an emergency, owners can at least charge the vehicle from a standard 120V outlet —albeit much slower than when using a dedicated 240V EVSE. One enterprising member of the My Nissan Leaf Forum, Phil Sadow, akaIngineer,” is an electrical engineer by profession and a born tinkerer at heart. After taking delivery of his own Leaf, he took a peek inside the trickle EVSE to see what made it tick. He discovered that, in reality, the cordset was already equipped with the proper wiring and circuits to handle 240V. With a minor modification, he was thus able to alter the unit to sense the amount of current available and charge at that level automatically. He then invented a way to also increase the amps from 12 to 16 when charging at the higher 240V so that the “trickle” EVSE (now misnamed!) could charge at the same rate as a dedicated, hardwired EVSE.

“Ingineer” offered to upgrade other Leaf owners’ cordsets for a fee, and thus set up EVSEUpgrade.com to handle the requests. He has been swamped with orders every since! His moonlighting business not only upgrades the onboard EVSE, but installs a locking NEMA L6-20 receptacle on its cord, ready to accommodate whatever adapters are necessary to plug into the wide variety of outlets available.

The very day I took delivery of my Leaf, I sent its cordset to EVSEUpgrade.com to purchase the upgrade and three L6-20 adapter cords, one of them already equipped with a standard 120V plug. I received the upgraded unit and connectors in just a couple of days. In the photo at the top of this page you can see the updated onboard EVSE, with its 120V “trickle” plug attached via the L6-20 connector.

To take advantage of the cordset’s upgraded 240V capability, I would need also other plugs for 240V outlets. There are actually a surprising number of different “standards” according to use: backup generators, welders and industrial power tools, electric stoves, farm equipment, clothes dryers, amplifiers, RV parks and marinas all seem to use different shapes, sizes, and numbers of blades. Probably the most common of these, however, is the 50-amp NEMA 14-50, nowadays used for dryer outlets and at most RV parks. There are also 14-30 and 14-60 variations for lower and higher amps, with different blades and slots on the bottom, as illustrated here:




In reality, however, the differing lower blades are for the neutral wire on these plugs, and thus unnecessary. It is consequently possible to simply remove that blade entirely from a 14-50 plug so that you can use it with all three of the corresponding NEMA 14 receptacles.

Long time EV advocate Stefano Paris recommends using a Camco PowerGrip Plug with its hand grip on the back for added safety, so I ordered a PowerGrip 14-50 to install on one of the L6-20 adapter cords I had purchased from EVSEUpgrade.com.

I am by no means an electrician, and was unsure exactly how to wire the L6-20 adapter cord to the PowerGrip, so I contacted EVSEUpgrade.com to ask a couple of questions. First, I noticed that the wiring in the cord included a small metal cable, along with the green (ground), white and black (power) wires. I supposed that this was what one might normally connect to the neutral blade in a 14-50 plug. Since the upgraded EVSE would not need that blade, I wondered what I should do with that metal cable. EVSEUpgrade.com told me to just cut it off. Which I did, as shown below on the left.

Wire you needed?
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Dia'grim Diagram
(Click to enlarge)

I was also hesitant about attaching the remaining wires, since they obviously didn’t match the diagram provided with the PowerGrip plug, as show above on the right. There was no red wire in the L6-20 adapter cable, so I assumed that its white wire should be attached to that blade instead. EVSEUpgrade.com confirmed that assumption, and below on the left is my edited version of the diagram to guide others who might wish to duplicate the project in the future.

Dia'grin Diagram
(Click to enlarge)

We’re screwed
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On the right above, you can see that this is exactly how I wired the cable to the plug. You can also see that there is a translucent glob in the slot for the missing neutral blade. This is silicone sealant that I used to fill that hole to help keep dirt and moisture out of the housing. On the left below you can see that silicone inside the slot from the front of the plug.

The hole truth
(Click to enlarge)

Capable cable
(Click to enlarge)

Voilà! On the right is the finished L6-20 to 14-30/-50/-60 cable, ready to put to good use with all those corresponding 240V outlets. In point of fact, the dryer outlet in my laundry room is a 14-30, and my Milbank RV panel has a 14-50 receptacle, so this cable will work with both. To test it out, one night I unplugged my hardwired EVSE, and plugged in the onboard unit to the Milbank panel using this adapter instead. The next morning I was happy to see that my Leaf had charged as usual on its timer during the night —and just as quickly.

I decided to wire the remaining L6-20 adapter cable to the next most common 240V plugs one might encounter: a NEMA 10-30 (for dryers in older homes) and 10-50 (for older stoves). You can see that they are almost identical, but in this case have different shaped blades for the ground wire:



The bad news is that Camco does not offer a PowerGrip model for these plugs, since they are not typically used in RV parks or marinas. The good news is that one can buy a single Leviton plug with interchangable -30 and -50 blades from most home improvement stores like Home Depot or Lowe’s. I surmise that I might run across an older style dryer outlet more often than one for a stove, so I installed the "L" shaped blade as the default plug, shown below on the left.

Gimme an "L"
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Blade Runner
(Click to enlarge)

On the right above is the assembled L6-20 to 10-30 cable. You can see the straight -50 blade lying next to it. I will keep it with the three adapter cables and onboard charger in my Leaf, as well as a small screwdriver, just in case I ever need to exchange those blades.

I doubt that will ever happen, but if Leaf owners do anticipate using both -30 and -50 outlets on a regular basis, it is possible to buy an adapter cable with a modified plug that will fit either outlet from EVSEadapters.com, yet another moonlighting business started by a My Nissan Leaf forum member. You will see that they also offer many more types of adapters, to fit practically any type of 120V or 240V outlet available in this country.