Revision 2 upgrade for Nissan EVSE - Allows full level 2!

Do we know the gauge of wire from the "control box" to the J1772 handle? Is it suitable for 30A? 24A? 20A? 16A?
Aside from modifying the PWM control signal, what are other limiting factors in the box that would prevent you from going all the way to 30A?
( I assume 30A is the hard limit due to the UL certification of the actual J1772 plug used. )

Obviously the current version of the Leaf means that rates over 16A are of marginal interest, but I wonder if the components in the box and cables are of suitable capability to support 6.6kW for future Leaf's and other 6.6kW capable vehicles?

( In my case being able to charge the RangerEV at full rate would be very handy. )

Another random idea for a rate select... A mercury switch inside the box. Mount flat or vertically for 12A. Position the box upside down (and let gravity do the work) if you want 16A. Or maybe it just defaults to 12A, but each time you rotate the box (during charging) it steps up to the next level. I guess you could use a gyro-sensor instead of a mercury switch. Or make it like the iPod shuffle mechanism where you shake the box vigorously to change rates.

I don't so much like the idea of shorting J1772 pins, or doing a secret handshake with the plug in sequence to select rate.

Another idea - a RF or IR receiver... They make very small close range transmitters and receivers. Maybe one of those "turn off the TV" one button remotes, or an RF doorbell mechanism or garage door opener. Hmmm. Maybe you could program the homelink in the vehicle to send the signal to change rates. There is already a programmable button on the rearview mirror for this! Then the box could have a small piezo speaker to beep different chimes to tell you what rate just got selected. (Higher octaves for higher rates.) Cycle in a loop between 12->16->20->

Sorry, just brainstorming out loud.

Seems the main concern with selectable modes is the 120v operation on a foreign car (since the current LEAF will always do 12a on 120v regardless of what the EVSE tells it), right? How often do you see a 240v circuit that ISN'T at least 20a? Would it be possible to have the programming know it's 120v and set the pilot to 12a, but 20a on 240v? That would alleviate the concerns, if I'm grasping them correctly.

EDIT: Oh, for the Quick220 users, duh. Sorry, wasn't thinking...

GeekEV said:

How often do you see a 240v circuit that ISN'T at least 20a? Would it be possible to have the programming know it's 120v and set the pilot to 12a, but 20a on 240v?

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A 20A continuos load on a 20A circuit is most likely going to trip the breaker and is beyond the NEC 125% rule. 16A continuos load on a 20A circuit is the maximum allowed according to the NEC 125% rule. Phil suggested the following in the first post:

Ingineer said:

4. Presently the unit charges at the standard 12A when used on 120 volt outlets and the full 16A when used on 240 volts.

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Phil, perhaps you could create a forum poll to gauge interest in the options you are proposing. 12A/120V and 16A/240V still seems like the sweet spot to me.

Spies said:

A 20A continuos load on a 20A circuit is most likely going to trip the breaker and is beyond the NEC 125% rule. 16A continuos load on a 20A circuit is the maximum allowed according to the NEC 125% rule.

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Granted. However most of the common 240v sources we would be using this modified EVSE with are at least 30A... I think it's rare that you'd see a raw L6-20 outlet in the wild and if you installed one yourself just for this, you have control over the breaker.

Of course, flexibility is a good thing, but I'm also a fan of the KISS philosophy...

TEG said:

Do we know the gauge of wire from the "control box" to the J1772 handle? Is it suitable for 30A? 24A? 20A? 16A?
Aside from modifying the PWM control signal, what are other limiting factors in the box that would prevent you from going all the way to 30A?
( I assume 30A is the hard limit due to the UL certification of the actual J1772 plug used. )

Obviously the current version of the Leaf means that rates over 16A are of marginal interest, but I wonder if the components in the box and cables are of suitable capability to support 6.6kW for future Leaf's and other 6.6kW capable vehicles?

( In my case being able to charge the RangerEV at full rate would be very handy. )

Click to expand...

As I mentioned before the wiring is #12 AWG throughout. I'm simply not going to consider exceeding 20A with this hardware, so lets take this off the table. I recommend you buy an AV.

-Phil

Spies said:

GeekEV said:

How often do you see a 240v circuit that ISN'T at least 20a? Would it be possible to have the programming know it's 120v and set the pilot to 12a, but 20a on 240v?

Click to expand...

A 20A continuos load on a 20A circuit is most likely going to trip the breaker and is beyond the NEC 125% rule. 16A continuos load on a 20A circuit is the maximum allowed according to the NEC 125% rule. Phil suggested the following in the first post:

Ingineer said:

4. Presently the unit charges at the standard 12A when used on 120 volt outlets and the full 16A when used on 240 volts.

Click to expand...

Phil, perhaps you could create a forum poll to gauge interest in the options you are proposing. 12A/120V and 16A/240V still seems like the sweet spot to me.

Click to expand...

If I implement selectable modes, then we can have a 20A setting, otherwise we will go with 16A for the reasons above.

-Phil

davewill said:

Wouldn't the plug/unplug sequence idea open up the possibility of having only a 15amp circuit available, but the device in 16amp mode with no way to change it but plugging it into the car and blowing the breaker? I guess you'd have to assume a 120v socket is always available in those cases. I like both the magnet and paperclip ideas, myself, and can see that the paperclip one is much simpler to execute. I can see where some people might be squeamish about poking around the J1772 with a paperclip, but we're enthusiasts, aren't we!

Click to expand...

If I implement the plug-sequence mode switch, then I simply delay output of any pilot signal until the mode switch selection time was passed. Since there will be no pilot signal for the car to acknowledge, there will be no current flowing when changing modes. I could also start off all modes at 8 amps and ramp up over a minute or so.

-Phil

Ingineer said:

If I implement selectable modes, then we can have a 20A setting, otherwise we will go with 16A for the reasons above.

Click to expand...

That makes the most sense. I don't know why we're all fixating on the 20A anyway, like you said, the LEAF can't use it. But more is better right? :lol:

.

I would also vote for 120v/12a 240v/16a. I hope you offer this by the time my leaf shows up.

rawhog said:

Don't you normally see two ganged 20 amp breakers to create a 240 circuit?

Click to expand...

Yes

Ingineer said:

I'm simply not going to consider exceeding 20A with this hardware, so lets take this off the table. I recommend you buy an AV.
-Phil

Click to expand...

Agreed. Looking forward to a mod that can do 240V@16A just for the Leaf.
( The old RangerEV isn't likely to go on any long road-trips anyways. )

Perhaps you could do current selection based on plug attached to the twist-lock? This is what Tesla mobile adapter's do.
(They put some diodes and/or resistors in the custom twist lock adapters so the box knows what is attached. )

If it were a NEMA14-50 end then 16A for campgrounds and such.
If it was a Quick220 then 12A since many of the 5-15s have only 15A breakers.

Perhaps default is 12A, but the NEMA14-50 pigtail adapter could have a diode to ground to force the box into 16A mode?

http://www.teslamotorsclub.com/showthread.php/5424-how-do-the-cables-work-technically

...The {Tesla} RFMC allows for three different signal levels. The processor is configured by placing a diode between the unused neutral (white) wire in the adapter and the ground wire. The absence of a diode signals the processor to produce a 16 amp signal. A diode in position in one orientation while signal a 24 amp signal and in the other orientation it will signal the processor to supply a 40 amp signal...

Click to expand...

Ingineer:

What I am about to propose is "blue sky" and is probably impossibly flawed/too complex, etc but here goes: For those who are interested in a Nissan EVSE Rev 2 upgrade that allows 120v to be selectable between 12a and 16a and 240v to be selectable between 16a and 20a (not useful for the current 3.3kW Leaf, but perhaps for future/upgraded charger Leafs or other >= 6.6kW charger EVs), consider the input plug to the EVSE being an L14-20P (or 30P required?) (4 wire) instead of an L6-20P (3 wire) with the use of specially wired pigtails being required to signal to the EVSE whether the higher or lower amperage output is desired, i.e. the ground and neutral in the L14-20R of the pigtail are shorted together ==> the higher amperage is desired and the other end of the pigtail being a 20a 120v plug like NEMA 5-20P or 30a 240v plug like NEMA 6-30P or 50a 240v plug like NEMA 6-50P, etc. When the lower amperage is desired the ground and neutral in the L14-20R are not shorted together and the other end of the pigtail would be a 15a 120v plug like NEMA 5-15P or 20a 240v plug like NEMA L6-20P. Note a neutral wire is not used in any of these (3 wire) pigtails.

Phil, if not feasible for any reason, it is sufficient to say NOT FEASIBLE!

An interesting idea. Though the "Phil standard" L6-20 doesn't have a neutral wire at all. It's two hots and a ground (or one hot, a neutral and ground when used in 120v mode) so I'm not sure that's feasible. Plus it would require you to have multiple adapters for similar outlets (where you can now get away with one). But it does raise an interesting possibility of using a 4 wire to the L6-20 and using the fourth wire to embed the selector switch in (or near) the L6-20 itself. You wouldn't have to penetrate the EVSE housing itself then...

Unfortunately it's not feasible to add a bunch of hardware for Rev 2. Definitely not going to install new cordsets and detection circuitry for adapter id!

Keep in mind in order to make this upgrade workable, it has to be low parts and labor cost. If we have to depot the board to add components or other circuitry, that would drive up to cost so much it wouldn't be reasonable.

I'm leaning toward a low-cost fixed 16a rev 2 option for those that want to use the unit as a replacement for a permanently installed EVSE. Those that are using their unit in a wide variety of situations, with possible Quick220 use, can just keep the rev 1 and be safe at 12a.

If I can easily implement a hardware-less mode switch, then I will.

-Phil

excellent work Phil

you will have another customer for Rev2 (as soon as Nissan can sell me a Leaf!)

FYI, I have heard there will be NO changes to the battery and charger on the 2012 Leaf.(stick with the 3.3kw)

no one can be sure but this seems to be likely and the source was reliable.

Kevin

Ingineer:

I am in favor of your "Rev 2" EVSE without mode select logic (KISS!).

However, I am interested how you might have designed the broad features of this EVSE if hypothetically you had been given the original design task at Panasonic...

I'll buy the new 12A/120v and 16A/240V model, if you are still offering this when the forgotten 36 get their Leafs. I don't see a general need for 12A/240V version. Maybe you could offer the original version as an option for customers with unique circumstances. I would perfer that the model I buy NOT be switchable for different amperages at 240V. Simpler means longer life and less possibility of problems.

Phil, you've got another customer for 240V@16A. I'm currently using your mod as my only EVSE, but parting with it to decrease charge times by 25% or so is a no-brainer. Agreed simplicity is best.