Why the EVSE at all?

What if the EVSE electronics were in the car, and a connector similar in safety and function to the J1772 (up to 80 amps) came out of the car and into the 240 volt receptacle in the wall? :idea:

The advantage would be that infrastructure would be simpler, the on board EVSE would be matched to the car and you would only get one to use anywhere. Most of us wouldn't even know that an EVSE exists at all.

Others in the office were asking the same thing. :?:

I know the exterior EVSE is a done deal politically, I'm just looking for the electrical engineering reasons. Thanks.

Dragging that box out of the trunk gets old, doesn't it.

I'm thinking smaller.. of a little spool of 12ga wire with a regular, normal, worked-for-generations 120v plug in the end. Enough with the EVSE.. just build it in, and give me the plug to plug in.

Nothing to steal, nothing to haul around and bang into your car, no expensive connectors.

Lift a flap, pull the plug out, plug it in, walk away.

Spring-coil retract would be bonus.

My understanding is that the EVSE adds considerably to safe operation between the EVSE box and the J1772 charging port that you otherwise would not have with a extension cord like cable between some outlet (like a 240v 30a drying outlet) and the Leaf.

I'm sure someone can provide a link to a summary of the benefits of a level 1 or 2 EVSE...

To make the universal connector work there needs to be a pilot signal from the wall.
And since most 240v circuits do not have a GFI, they put one in the wall box.

Otherwise I think the car could just plug in with a normal NEMA 6-20 plug and cord attched to the Leaf and would be fine.

Somebody must think people will get confused if the filling station does not have a cord, hose or nozzle. Just be glad every appliance is not like this :roll:

Folks, 120v.
The very same cord that people use for their engine block heaters, boombox.

I'm just not seeing the advantage to a $800 box hanging from a 6" cord with a monstrous cord and plug to the car. Not at 120v 1400W. My coffee maker seems to do just fine with a standard plug.

Some future EV will have a simple "pull out" 120v plug, and when they pull up next to me and have their car plugged in while I'm still fishing the EVSE out of the trunk, then it will be all too clear.

think 10 million people doing it.
think safety.
think doing it in the rain or snow.

Think how many RVers have plugged in each day in the rain and snow.
Non issue.

smkettner said:

Think how many RVers have plugged in each day in the rain and snow.
Non issue.

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we stay plugged in, allot.

thankyouOB said:

think 10 million people doing it.
think safety.
think doing it in the rain or snow.

Click to expand...

OK

I picture a J1772 connector getting plugged into the wall. The receptable can have a mechanical switch that keeps the juice off until the connector positively snaps in. They could then build a spring loaded switch to turn on the juice manually--a double safety--kinda like the 1911 ACP.

I've been told the J1772 is safe in the rain.

I could see the 50 amp oven connector with its giant bare metal connectors not being the safest for daily plugging in, so lets go with the J1772 like connector.

http://www.allcarselectric.com/news...nd-why-does-your-electric-car-charger-need-it

This article sheds a little light, though I'd still like to hear what some of the EE on this forum say. The early EV's didn't need the EVSE.

All great points, and.... every single part of the EVSE could be built INTO the car.

So long as the car includes a 120v EVSE, it's no safer than a pull-out cord that plugs in exactly the same way.

I'm not talking about 240v 70A here.. just the 1,400W 120v EVSE that I'm tired of dragging in and out of the car twice a day.

The Nissan EVSE is intended for occasional emergency use. An EVSE is essential to tell the car(s) it connects to how much power the circuit is capable of providing to your car. I may be able to only supply 16A so a Tesla needs to know this so it will not draw more. This is why the EVSE is not in the car, at least one of the reasons. An EVSE is not able to regulate power output, only a charger. This has been fully hashed out here before. In addition, just because EVs did not have them before did not mean it was better. The old method of charging was antiquated and not exactly safe.

DrRocket said:

The early EV's didn't need the EVSE.

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Define "early"...? EVs in the late '90s (EV1, RAV4EV, RangerEV, etc.) all used EVSEs.

I think the primary benefits are safety and durability.

Another benefit is that it is a specialized connection for EV charging, so you don't have to worry so much about other people trying to use it for RVs, space heaters in their vans, etc.

In public places where NEMA 5-15, and 14-50s are left out in the open you tend to see motor homes show up for the free power.

EVDRIVER said:

The Nissan EVSE is intended for occasional emergency use. An EVSE is essential to tell the car(s) it connects to how much power the circuit is capable of providing to your car.

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How do I reword this to be more clear?

I would like the occasional emergency-use EVSE to be "built into" the car, with only the 120v plug and some retractable cord exposed.
Am I seriously the only one that thinks this would be better than what we have now?

This way, I don't have to drag a box out of the trunk, hang it from the wall, and plug it into the front of the car every time I park at work.

So ... in a way ... you are asking for a THIRD charging port ? (std NEMA extension cord (120V, L1), J1772 (240V L1/L2), DC QC)

LEAFer said:

So ... in a way ... you are asking for a THIRD charging port ? (std NEMA extension cord (120V, L1), J1772 (240V L1/L2), DC QC)

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Yup, exactly.
In fact, I'd gladly trade my useless DC QC port for a simple 120v retractable cord. Can you guess which one would get more use?

GroundLoop's point has some validity for 120v, which, of course, is what he is talking about. The same argument does not apply at all to 240v. Receptacles for 240v are different for every amperage they support, and this is rather important, because that is the only means the receptacle has to control the maximum current going through it. We keep saying the 3.3 kW charger is too slow, and we want a 6.6 kW charger. But if you plug a 6.6 kW charger into a 20 amp circuit, and don't tell it to downrate itself, it will very quickly trip the circuit breaker. The EVSE/J1772 protocol gives a way for the charger in the car to be told how fast it can run. Without an external EVSE, and with a 6.6 kW charger, you would need three wires that you can pull out of the car: one for 15A 120v, one for 20A 240v, and one for 40A 240v. If you want to support 30A circuits, or even faster chargers, you will need even more wires.

I credited GroundLoop's argument with some validity for 120v, but not even full validity there. Our current charger limits itself to 12A at 120v, which is what is safe for a 15A circuit. But many household circuits are 20A, and could support 16A charging at 120v. To do that safely without an EVSE you would need to use a rotated prong in the plug, so it could plug only into a 20A outlet. (Those outlets have a T-shaped slot on one side so they can accept either what we think of as a "normal" plug with parallel prongs, or the special 20A plug with the rotated prong.) Now we need two different wires coming out of the LEAF just for 120v charging!

Ray

A specialized smart breaker could replace an EVSE, the first time you plug-in it sends an AC signal thru the cable, informing the car how much power it can provide.. there would have to be some high frequency filtering so the information does not backfeed to other smart breakers in the circuit (if there are any).. it probably would not even be a bad idea for all the breakers in your house.. imagine if this special breaker continually transmitted how much power it had available to the appliances plugged into its circuit.. you try to plug in a hairdryer and a led in the plug starts blinking telling you there is insufficient power available.

The main reason for the EVSE is to keep the EV connector contacts from breaking connection under load. The design of the connector prevents this by breaking the signal-current pilot connection first, which de-energizes the power contacts before they break. If this were not done, eventually the contact surfaces would degrade to the point where connector would overheat at high load. By placing the relay which breaks the current at the wall end of the cable, the cable is also de-energized when the vehicle is able to move and is most likely to drive over and damage the cable. A secondary function of the EVSE is to tell the EV how much current it can safely draw without blowing the branch circuit breaker. The EVSE also has a GFCI and ground integrity testing to protect the user.

While a savvy user might be able to deal with any of these issues, the point of the EVSE is to take care of them; when EVs are adopted by the masses it's likely that many users will not understand these safety issues.

Since the 120v connection could be to a 15A or 20A breaker, MIGHT an EV's charger be designed to follow the EVSE's Max-Current "advice" and draw 16A when "advised" that it is OK to do so (using a 20A breaker and circuit)?