Available EVSE Info (J1772 Jan 2010)

[EVDRIVER]

Why is an 240V EVSE necessary to charge the Leaf at home? As I understand from my EE friend, battery management is built into car. You can plug directly into any 110V outlet. Why not the same for any 220V outlet? Apparently the Leaf home charging station simply puts out a signal that the 220V station is being used. The battery management system in the car controls the flow of electricity into the car's battery pack.

So, are systems being developed to avoid using the expensive and rare home charging stations? For example, with multiple residences or when visiting family or friends overnight, it would be nice to be able to plug into any old 240V outlet.

Lee

You can use 120V with the supplied unit, it will take about 19 hours VS 8. The BMS has nothing to do with the EVSE or the AC supply voltage, the BMS talks to the charger which is in the car, the component you are calling a Leaf charging station is not a charger but a cord that supplies 240V to the charger which charges the pack and is regulated by the BMS. The EVSE is improperly called a charger often and that may be why you are confused.

 

[Lee]

Thank you for clarifying the terminology for me. So, returning to my original question, why is the EVSE necessary at all?

Lee

 

[DeaneG]

Thank you for clarifying the terminology for me. So, returning to my original question, why is the EVSE necessary at all?

It has two main purposes: 1) to keep the operator from getting hurt (like a GFCI outlet in a kitchen or bath), and 2) to tell the car what maximum charging power it is allowed to draw from that plug.

 

[Lee]

How would I get hurt plugging into a 240V socket? Can't the Leaf charger and BMS detect a 240V source without needing an EVSE?

 

[EVDRIVER]

How would I get hurt plugging into a 240V socket? Can't the Leaf charger and BMS detect a 240V source without needing an EVSE?

Again, the EVSE and AC supply has nothing to do with BMS. The charger detects 120 or 240. The 240V home EVSE provides extra safety and the proper signaling for the on board charger as well as the J1772 cable. You don't need it as you can use the 120V EVSE that is included with the car but you it will take about 19 hours to charge. If you want 8 hour charging you will need some brand of 240V EVSE.

 

[Lee]

Sorry, I am still having trouble with the technical jargon; thanks again for clarifying

1. If you can plug directly into 110V, why not the same for 220V? As you noted, the LEAF charger can detect 110V or 220V.

2. What is so dangerous about plugging into a 220V socket?

It just sounds to me like Nissan has added a needless layer of cost and complexity with the EVSE.

 

[DeaneG]

How would I get hurt plugging into a 240V socket?

Most 240v sockets do not have a ground fault interrupter, which would cut off current flow if for some reason the 240v went through you into the ground (on a rainy day for example), instead of into the car. The EVSE provides this function.

 

[DeaneG]

Sorry, I am still having trouble with the technical jargon; thanks again for clarifying

1. If you can plug directly into 110V, why not the same for 220V? As you noted, the LEAF charger can detect 110V or 220V.

2. What is so dangerous about plugging into a 220V socket?

It just sounds to me like Nissan has added a needless layer of cost and complexity with the EVSE.

1) You can't plug the car directly into a 120v socket. Your friend was incorrect when he told you that you could. You have to use an EVSE. That's the cord with dongle which comes included in a pouch in the trunk of the Leaf. The included EVSE is only rated for 120V/12A.
2) See previous post. EV car manufacturers have standardized the charging accessories' functions and operation to protect the car and the operator (us).

 

[EVDRIVER]

Sorry, I am still having trouble with the technical jargon; thanks again for clarifying

1. If you can plug directly into 110V, why not the same for 220V? As you noted, the LEAF charger can detect 110V or 220V.

2. What is so dangerous about plugging into a 220V socket?

It just sounds to me like Nissan has added a needless layer of cost and complexity with the EVSE.

It's an industry standard. If you want more info you can search the threads, this topic has been beaten to death. You need a 120 or 240 EVSE, it's not a Nissan thing.

 

[evnow]

1) You can't plug the car directly into a 120v socket. Your friend was incorrect when he told you that you could.

Well, that is just semantics. You can plug the car directly into 120V socket - using the appropriate cable.

 

[DeaneG]

1) You can't plug the car directly into a 120v socket. Your friend was incorrect when he told you that you could.

Well, that is just semantics. You can plug the car directly into 120V socket - using the appropriate cable.

Fair enough, but I was trying out for a junior membership in the EVSE nomenclature police committee

 

[garygid]

Using the same "jargon", you can "just" plug the car into any
240 volt socket as well, as long as you have the appropriate "cord".

Basically, an EVSE is that "cord".

 

[smkettner]

Yes Leviton 16a plugs into 6-20R (240v) and the 32a plugs into the 6-50R also 240 volt.
Just make an adapter from the 240v supply that you have.

 

[evnow]

Using the same "jargon", you can "just" plug the car into any
240 volt socket as well, as long as you have the appropriate "cord".

Basically, an EVSE is that "cord".

Right. Once the prices come down and get smaller that is how we will look at it.

Just the way people think of a laptop "cord" now.

 

[tps]

Thank you for clarifying the terminology for me. So, returning to my original question, why is the EVSE necessary at all?

It has two main purposes: 1) to keep the operator from getting hurt (like a GFCI outlet in a kitchen or bath), and 2) to tell the car what maximum charging power it is allowed to draw from that plug.

Actually, it has a third important purpose, which seems to be overlooked a lot: 3) When the plug is disconnected, the current is automatically shut off before the current-carrying contacts disengage. This is done to prevent arcing, which would degrade the contact surface were it allowed to occur. If not for this feature, the operator would have to shut off the disconnect switch or breaker each time the connector was disconnected.

 

[Coffee_Slurry]

I'm going to take a wild guess that an ambitious hardware hacker could convert the supplied 120v adapter into a 220v adapter.

There's probably very little in the unit that cares about voltage.. the heavy lifting is done by the car's charger anyway.

Just saying..

 

[DarkStar]

I'm going to take a wild guess that an ambitious hardware hacker could convert the supplied 120v adapter into a 220v adapter.

There's probably very little in the unit that cares about voltage.. the heavy lifting is done by the car's charger anyway.

Just saying..

It all depends on how the GFCI and the internal power supply for the pilot signal function. If the internal power supply is dual voltage (120/240) in theory the GFCI could just be defeated and all would be good. Personally, I'm not sure that the GFCI will even need to be defeated as I don't know what the differences are between the 120 volt and the 240 volt versions.

The car just checks the L1 and L2/Neutral for the voltage, checks the pilot signal for the amperage rating, and then starts charging!

I'm acquiring a 240 volt EVSE in a week or two and plan on opening it up to determine how to connect it to 120 volts for demonstration purposes, however I will expect it to be able to be a fully functional EVSE at 120 volts.

 

[smkettner]

The risk I see in converting the 120v to 240v is the smoke will come out of the signal generator.
I thought there was just a relay in the 120v.... No GFI. I think it is designed to plug into a GFI outlet.

 

[DarkStar]

The risk I see in converting the 120v to 240v is the smoke will come out of the signal generator.
I thought there was just a relay in the 120v.... No GFI. I think it is designed to plug into a GFI outlet.

All J1772 EVSEs are required to have internal GFCIs. They may have reduced costs by using a dual voltage DC converter for the pilot signal, which would help. But we won't know until we can open one...