Level 1 Charger - does it work on 240v?

Yes, it is standard practice in a scenario like this to use a white wire as a "hot" lead.
Black tape is wrapped around the white wire (at both ends) so that it is no longer white to signify that it is now 'hot'.

 

I've always wanted to know this. I have a dedicated Level-II EVSE that I use at home (I rarely charge anywhere else) but it would be nice to press my OEM charger into service at a Campground or RV hookup while travelling. Most KOA facilities have a NEMA 14-50R receptacle.
Naturally, the 100% safe way of doing this is to buy an inline EVSE with the right plug, but then my OEM unit will hardly ever be used. Besides, I'm cheap, and do not want to spend another $300+ for an aftermarket EVSE. I may just roll the dice on this. The worst thing that will happen is that I smoke my Honda OEM EVSE, which would be a pity, because the thing is built like a tank.

In theory, it could work. I have built EVSEs and I am also an electrical engineer. The main components of any EVSE are:

1. Heavy-Duty Relay (contactor) that connects the AC Mains to the vehicle. It turns on and off via an electromagnet (coil). The heft of this contactor is determined chiefly by the rated current. The higher the current, the beefier the contacts must be to safely carry it. The applied voltage determines some of the physical dimensions of the contactor parts like spacing and creepage distance. The vast majority of relays used in these types of devices can safely switch up to 250VAC at the rated current.

2. Protocol Controller: This is a microprocessor-controlled circuit that "advertises" to a connected vehicle how much current can be safely supplied by the EVSE. That information is used by the vehicle's onboard charger to set an upper limit of how much current will be drawn by the vehicle. The Protocol Controller also detects when the EVSE is plugged into a vehicle and performs all of the sequencing and control activities that eventually result in energizing the contactor coil.

3. DC Power Supply. This is a switching power supply not unlike the one used to power a laptop PC or a smartphone. It takes the AC Mains voltage, and converts it into a regulated low-voltage DC for powering the Protocol Converter, and in turn, the contactor coil. Most modern power supplies are capable of accepting a wide range of input voltages, typically 100VAC to 240VAC. The DC output voltage is always the same.

Now, for the OEM charger:

It makes sense for an OEM to have as few versions of a device as possible to hold down costs. Computer manufacturers have been doing that for years. An external power supply for a Lenovo laptop PC is exactly the same the world over. The only thing that changes is the removable power cord that is plugged into the outlet of whatever type and voltage exist in your country. Anywhere in the world, that voltage will be between 100 and 240V. For this reason alone, I strongly suspect that the Honda OEM EVSE is designed that way.

To make a Universal EVSE (100-240V) you need only:

1. A DC power supply with universal input.
2. A two-pole contactor. In theory, a single-pole unit is sufficient to cut the current, but for safety's sake, both current-carrying wires must be interrupted when switching power on and off for North American 240VAC systems.

Since the Protocol Controller operates entirely on low-voltage DC, it has no awareness of the Mains voltage if the DC is coming from a Universal power supply.

The pilot signal will still "advertise" a maximum current of 12A, (for most OEM Level-I EVSE). If, however, the EVSE is plugged into a 240VAC mains, the contactor will now switch 240VAC to the vehicle, and you will charge twice as fast (same current, twice the voltage = twice the power).

About the Plug:
The Honda OEM charger comes with a NEMA 5-15 standard plug for 120VAC circuits. This is the same type of plug you will find on common household appliances. There is a twist, however. The plug has embedded inside, a sensor that monitors the temperature of the two current-carrying blades. If they get too hot, it will cut off the charger. This is a safety feature to prevent outlets from overheating. Outlet contacts wear out with time and become loose, increasing the resistance of the connection which makes them get warmer as more current flows through them. The EVSE will draw 80% of the maximum rated capacity of a brand-new NEMA 5-15 outlet, so there isn't much wiggle room. If your outlet is old and flabby, it will get hot quickly.
This means that the OEM plug CANNOT be removed and replaced with a 240V plug, such as a NEMA 6-15. Without the temperature sensor, the charger will not operate, and it will present a safety hazard besides.

I examined my charger and noticed that the input cord (pigtail) is removable, much like the power cord on a computer power supply. To remove the cord, the cover must first be removed. I have a set of 3-point security screw bits, so that was easy. Once removed, depress a little locking spring, and screw off the connector at the box. The pigtail pulls right out, revealing a weird, proprietary 5-blade connector. (Two for the current-carrying wires, one for the safety ground, and two for the sensor) Certainly, other pigtails could be offered by the OEM to suit different kinds of outlets. I have looked high and low for a 240V pigtail that will fit the box, but have been unsuccessful so far.

Now, if one is brave (and doesn't mind creating a major electrical code violation and possible safety hazard), they can make a home-brew adapter as follows:
1. Get a 240V plug, such as a NEMA 14-50
2. A short length of 12/3 portable cord
3. An inline NEMA 5-15R receptacle

Use the green wire to connect the Ground pin of the plug to the ground pin of the inline socket.
Wire the two Hot contacts of the plug to the remaining two contacts of the socket. (THIS IS A BIG NO-NO by the code book because the silver screw is supposed to be neutral, never hot. Do this at your own risk!)
Leave the Neutral contact of the 240V plug unconnected.

The stock NEMA 5-15 plug on your EVSE will mate with the socket on your adapter, which will now supply 240VAC to the two current-carrying conductors.

Rolling the dice:
When you plug the adapter into a 240V outlet, one of two things will happen:

1. You will learn for sure if the internal DC power supply in your EVSE is capable of functioning on 240V. If it's not, you will immediately smoke the charger. Most likely, the worst thing that will happen is that an internal fuse will blow. It is highly unlikely that the unit will catch fire, but you'll now have a $400 brick.
2. The EVSE will work like a champ, and happily send 240VAC at 12A to your vehicle, charging it at twice the rate. (2880 Watts, or about 8 miles/hour).

Now- there are two practical problems with this approach:
1. The adapter is a hazard if someone attempts to plug some OTHER 120VAC rated device into it. The device may be damaged, and there could be a shock hazard. This is why 240V plugs have a different blade configuration.
2. The built-in sensor will still detect a hot plug, but will have no awareness of the 240V plug blade temperature. That is not likely a problem, because a NEMA 14-50 plug can carry 50A, so it would have to be really worn-out to get hot at a measly 12A

For a chart of common NEMA flat-blade plugs:
https://www.menards.com/main/buying-guides/electrical-buying-guides/plugs-connectors-buying-guide/c-1467312433250.htm

 

@Daniel Sandoval,
Hello, and welcome to the Forum !

Although I have not done this personally, there are many here in the forum who do this. These pioneers have saved you from the anxiety of "rolling the dice" and waiting to see whether the smoke appears or not !

And yes... Your list of "practical problems" must certainly be considered carefully. I kind of feel like anyone who understands this as well as you do, can certainly do this safely. You just have to be careful to never have the "240V" NEMA 15-5R receptacle powered and laying around such that somebody who is uninformed might plug a 120V device in. If someone reading this does not understand it 100%, then don't mess with this.

My suggestion would be to attach your homemade adapter to the OEM EVSE and secure them together (maybe with zip-ties or similar) so someone could not casually de-mate them exposing the improper voltage. In effect, you have made the NEMA 14-50 almost an integral part of the EVSE.

 

My friend uses the below adapter from Amazon everyday with his Ford OEM EVSE and his Ford Fusion Energi PHEV. I did a quick 10 minute test with this adapter on my OEM Clarity EVSE cord with my Clarity and everything seemed like a perfectly normal charge at 240 volts. I already have a 240 EVSE at home and a portable 120/240 EVSE I keep in the trunk so I do not have any need for it but it is good to know I can.

https://smile.amazon.com/dp/B075FTC9RT/ref=cm_sw_em_r_mt_dp_ABANSR0QBP192PYBPT23?_encoding=UTF8&psc=1

 

This is fine with a compatable 240V outlet (NEMA 6-15R).

The OP had expressed a desire to connect to a campground receptacle (typically NEMA 14-50R). It may be possible to find a pre-made adapter similar to the one in your link, but most ready-made adapters with NEMA14-50 at one end, would have either a different style of 240V or multiple 120V outlets at the other end which would not serve the purpose. I would strongly recommend against using 2 adapters to get there...

 

I’ve shown this before, but here’s my home made adapter cable:



Each blade carries 120v, the pin is ground and I left off the neutral blade to avoid confusion. It’s handy when charging midday for a couple hours to pick up 20 miles of EV range as opposed to 8 miles.

And here it is in use the other day with a 50A RV pedestal:

 

Daniel: That's a lot of work. It's way easier to run your OEM Honda evse on 240v: I've used my Honda OEM evse countless times on 240v power.

I used a NEMA 6-20 extension cord, cut off the receptacle end and replaced it with a NEMA 5-20 receptacle. Plug the Honda OEM evse into the modified extension cord... at the plug end I have a NEMA 14-50 to NEMA 6-20 adapter to connect to 240v power. I then plug my 6-20 cord into the adapter from the outlet. Since the Honda evse is only pulling 11 amps, the 20 amp rating of the 6-20 extension cord (it's only 6' long) is enough to easily handle the electrical load.

I chose the NEMA 6-20 cord as they are relatively inexpensive and the cord is flexible enough to easily cut and graft a NEMA 5-20 outlet on the end of the cord.

No modification of the Honda evse is needed, allowing you to still use it on 120v outlets. Takes about 5.5 hours to charge a fully 'empty' battery. Pulls ~11amps @ 240vac.

 

Are you staying in an RV while the car is parked at the campground? We recently did a 10-day, 3-stop trip of about 600 miles total. I drove the coach and the wife drove the Clarity. The drives between stops were only 2-4 hours, so we decided not to tow the Jeep. We just used the 15A outlet on the pedestal for the car and kept the coach plugged in to the 50A service. Other than the rolling days, we used no gas.

 

I should have mentioned my friend also has a 14-50 RV type 240 volt outlet in his garage. He purchased an adapter at Home Depot. He wanted the 50 Amp outlet for future proofing and is fine with commonly available high quality adapters in the meantime. https://www.homedepot.com/p/AC-WORKS-10-3-STW-1-ft-14-50P-50-Amp-RV-Range-Generator-Plug-to-6-15-20R-20-Amp-250-Volt-T-Blade-Connector-S1450620-012/303873836

 

You can buy that same adapter on Amazon for $30: https://www.amazon.com/14-50P-T-Blade-adapter-4-Prong-Adapter/dp/B081PZCR65/ref=sr_1_2_sspa?dchild=1&keywords=nema+14-50+to+6-20+adapter&qid=1630946402&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyUlcxMUhSSlU4UlVYJmVuY3J5cHRlZElkPUEwNzAxMjQ5MTJEQUZQSEFLMjg3OSZlbmNyeXB0ZWRBZElkPUEwMzMyMTk4MklGVVg1QjI1NVdVUSZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

Looking at both the Amazon and Home Depot items, it looks to me like the stock EVSE cable would not plug into either, given one of the receptacle slots is horizontal, not vertical. Or am I missing something.

 

No, not directly. I used a custom NEMA 6-20 to NEMA 5-20 to adapt that to my honda evse.

 

Got it.

 

Last June I took a 6000 mile trip in our Clarity - CA to Western NY and back. I stayed in campgrounds, usually with either RV 14-50 or a 120 volt outlet. I took both the Level I EVSE and my Juicebox 40 plug-in EVSE. I used both, but found the Juicebox to be heavy and awkward to use while traveling. (It's been great for home use.). Next time, I'll only take the Level I EVSE and an adapter for RV 14-50, 240 volt use. I'd still want that shorter charge time with the adapter to guarantee a full charge overnight. BTW, the Clarity was a great car for that cross-country trip.

 

The Home Depot adapter fits it directly. The female end has a slot that accommodates both the horizontal blade from a 15 amp plug and the vertical blade of the 20 am plug. Look carefully.

 

Interesting. You stayed in campgrounds. Did you sleep in the car or did you bring a tent? I'm curious to see your route. Did you publish it anywhere?

 

@The Gadgeteer,

The Home Depot adapter you reference will not work with the OEM EVSE.

The Home Depot Adapter has an NEMA 6-15 / 6-20 receptacle that looks like this:

You cannot plug a standard 120V plug into this receptacle (for good reason, because this receptacle is 240V). I realize that is the intention here, but in general, it is not safe so the keying does not permit it...

Here is the plug on the Honda OEM EVSE. It is a regular 120V plug (NEMA 5-15p):


Note that the horizontal receptacle contact blocks the vertical blade of the plug.


You may be fooled by the appearance that a "20 amp" 120V plug could fit into the NEMA 6-20R...
Here is a 20A 120V plug (this is a NEMA 5-20p, but I have never seen one in real life):

At first glance, this "appears" to have the same configuration, but it does NOT. Again the horizontal receptacle contact will block the vertical blade on the plug.

The NEMA standards are totally oriented around safey, and it is virtially never safe to plug a 120V device into a 240V receptacle so the contact configurations do not permit it.

The EV community has found a rare exception, but you need to build (or buy) a specialized adapter to do it !

 

MrFixit, thanks for taking the time to explain it so well.

By the time you bought either the Home Depot or linked Amazon part and then added some sort of adapter to force it to work, one could just as easily make up an adapter cable with the appropriate plug and receptacle.

On Amazon, the plug is about $12, and I don’t think it was much more at Home Depot. The receptacle appears to be about $4. The cost of the 10ga 2 conductor plus ground cable will depend on the length you choose, but altogether you’d probably be in for less than $30 for one like mine.

As an aside, I made up two - the one discussed for the 50A RV receptacle and another for an existing 30A RV receptacle I have in the hangar of my TN home.



Both have worked flawlessly…with one exception. As I’ve mentioned before one of the screw connections on the 50A plug came loose, causing overheating and some melting of the receptacle. Just be sure your connections are rock solid and be sure to check them once in a while.

 

I completely agree with you with one caveat -

You and I (and MANY others in this forum) are electrically and mechanically savvy.
For those with no mechanical or electrical knowledge, skills, or experience, I suggest leaving this alone.

There are lots of people who shouldn't change the plug on a lamp. Everyone needs to be aware of their own strengths and weaknesses !

 

Good point. I might add “…or find a qualified friend to help you”.