Not too many convenience chargers accept 240V, almost all are set up for
110V only (in USA).
When you only provide an outlet, the EV driver needs to use their EVSE
instead of just plugging in the cord.
NOTE that the situation is radically different in Europe, where you only
find a pole sitting at the edge of a parking slot
with a Mennekes plug (if I am not mistaken).
The EV driver brings the cord to plug into the charging pole and into
the car. It is just a wire though, not a complete EVSE.
I have considered installing an EVSE at work without the cord (as we
have frequent events of copper thieves passing by)
by installing a standard plug on the EVSE such as a L14-50 socket and
make the cord available at the front lobby for anyone who
needs to plug in - just the cord with the L14-50 plug on one end and the
J1772 at the other end.
Without exposed wire, the copper thieves will not bother the charger.

-----Original Message-----
From: EV [] On Behalf Of Haudy Kazemi
via EV
Sent: Thursday, December 14, 2017 10:30 AM
To: Electric Vehicle Discussion List; Bill Dube via EV;
Cc: Haudy Kazemi
Subject: Re: [EVDL] Combating ICED EV parking spaces

A mix of options would be preferable IMO. L1 outlets in most places, and
some L2 stations marked with signs saying 4 hour limits. A notification
system that charging is done or that a space is available would be a
nice enhancement.

One thing is I'm not convinced that providing L1 120v outlets is
actually much less expensive than providing L2 240v outlets (note I said
outlet here, not EVSE/station). Why? Because the wire and conduit will
need to be sized according to the continuous current demand. This in
turn means using at least 10 or 12 gauge wire to keep voltage drop at 12
amps over some distances. Big parking areas could need even larger wire
just to handle voltage drop. At 240v, voltage drop will have less of an
effect (percentage wise) for the same distance. In short, 240v outlets
like NEMA 6-20 allow for smaller wire or longer distances. 
The other aspect the number of outlets per circuit. 240v is commonly
done as 1 outlet per circuit wheres 120v often has several outlets per
circuit. This works for 120v because most loads are intermittent high
loads (microwave, vacuum) or low continuous (lights, TV). EVSE loads are
generally high continous. L1 EVSEs usually limit themselves to 12 amps;
in a parking lot, that would need one circuit per parking space assuming
EVSEs all were active at once together. In short, 240v needs the same
number of circuits. (One difference, though, is 240v will use 2x the
electric panel circuit breaker slots.)

It is also possible to do this with power rationing. Several OpenEVSE
based solutions have been developed to allow multiple vehicles to share
a single 240v circuit. Tesla has also done this with their high power
wall chargers that allows up to 4 be linked together.

My recommendation: run wire/conduit that allows for an easy conversion
from 120v to 240v circuits. If providing dedicated outlets, plan on 12
amps per actively used parking space. If using linked EVSEs then check
the EVSE specs to see its sharing capabilities.

Last consideration: I am getting the impression that newer EV owners
tend not to be as interested in pulling out an EVSE each day to connect
their cars. Doing so is a hassle (esp rolling cord up afterwards) and it
leaves their personal EVSE vulnerable to incidents.

On December 14, 2017 11:32:32 AM CST, Bill Dube via EV
<> wrote:
>I tend to agree with Paul.
>The installation of 120vac outlets are a tiny fraction of the price of 
>the installation of L2 charging pedestals.
>If you spread them around over many parking places, (like they do in 
>the great white north for block heater outlets) there will be less 
>competition and contention over them.
>Keep in mind that a single 120vac 20 amp outlet can easily supply an EV
>with 50 or 60 or perhaps 70 miles of charge over a 8 hour workday. This
>covers 99% of commutes.
>Level 2 or 3 may be what is sexy and flashy, but Level 1 is probably 
>optimal for charging at work, given all the constraints. The ~$7k you 
>would spend on installation a Level 2 charger pedestal would easily pay
>for 20 Level 1 outlets spread over 20 parking places.
>Bill D.
>On 12/14/2017 6:13 AM, paul dove via EV wrote:
>> I say put 120v outlets in every spot and let people park where they
>> Sent from my iPhone
>>> On Dec 13, 2017, at 3:55 PM, Cor van de Water via EV
><> wrote:
>>> Correct,
>>> Green means "available" so you would instinctively expect an empty
>>> at a green light.
>>> I would suggest a slight change to the meaning of the colors:
>>> Red = charging (no matter how fast/slow) Yellow = charging ended, 
>>> spot should be vacated as soon as possible (grace timer) Green = 
>>> charging and grace timer ended, spot is available (even if
>>> EV still plugged in).
>>> Anybody parked in a "green light" spot is suceptible to ticketing
>>> towing.
>>> Grace time can be tuned to match need/demand, with appropriate
>>> When a "yellow" charging space is vacated, an EV can immediately
>plug in
>>> and turn the
>>> spot to "Red" again.
>>> If a spot next to the EV charging spot is available and an EV
>>> that urgently needs a charge,
>>> it should be perfectly fine to unplug a "Yellow" or "Green" charger.
>>> Preferably he leaves a note at the car, how to contact him and how
>>> he needs to charge
>>> before it is OK to unplug when the official EV charging spot is in
>>> again.
>>> Note that it is possible to implement a max charging time with this
>>> well:
>>> Towards the end of the max charge time the light turns yellow and
>>> the charge time
>>> has expired, it stops charging but may allow an additional grace
>>> before the light
>>> turns green again and you should be on your way (or moved out of the

>>> spot at least).
>>> At companies with high contention for too few spaces, it makes sense
>>> force everyone
>>> to switch during lunch time (for example max 4 hours charging).
>>> Many EVs already announce how long charging is going to take, so it 
>>> should be no surprise how long one can leave the car before it needs

>>> to be
>>> Obviously it is user friendly if the charging station sends you a
>>> when charging ends
>>> and the grace time starts.
>>> -----Original Message-----
>>> From: EV [] On Behalf Of EVDL 
>>> Administrator via EV
>>> Sent: Wednesday, December 13, 2017 1:40 PM
>>> To: Electric Vehicle Discussion List
>>> Cc: EVDL Administrator
>>> Subject: Re: [EVDL] Combating ICED EV parking spaces
>>>> On 13 Dec 2017 at 13:08, Lawrence Harris via EV wrote:
>>>> I would love to see a big light on the top of the charge head that 
>>>> goes green while charging, amber when the charger ramps down to the

>>>> end of charge and red when done.
>>> Outstanding idea, but I'd recomment the exact opposite of the colors
>>> red for bulk charging, amber for absorption (last 20%), and green
>>> charged.
>>> That's  because almost every other charger used on personal gadgets 
>>> (phones, cordless drills, and so on) uses those colors or something 
>>> similar. It's read for charging, green for done, and sometimes you
>>> yellow or flashing green during the absorption phase.  I don't think

>>> I've ever seen any other charger that was lit up red when it was 
>>> finished, except for a couple that never changed color.
>>> David Roden - Akron, Ohio, USA
>>> EVDL Administrator
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