Nissan L1 EVSE third-party upgrade to both 120V and 240V

Not a requirement for 120v EVSEs, I believe.
However it is required for plug-in 240v (L2) EVSEs.
Also, plug-in 240v EVSEs are only allowed for "indoor" use, not "outdoor".
(see NEC 625.13)

Question: If I were able to offer an additional upgrade level for the EVSE to a selectable 20A, would it be worth it?

I did some more digging, and I believe with some time investment I could update the unit's software such that we could add a user selectable current. (up to 20A)

All the components in the EVSE are rated to 20A, so this is possible w/o any additional hardware modifications. The Leaf would only pull ~16A on 240v, but it might pull more on 120v if permitted so that would be a reason to go over 16A. (I'll have to test this)

The time investment would be significant, so wanted to gauge interest. If you are interested, what would it be worth to you?

I would be. Let me know how much more it would cost. Thank You April deliveryJim Tubbs [email protected]

Ingineer said:

The time investment would be significant, so wanted to gauge interest. If you are interested, what would it be worth to you?

Click to expand...

A definite maybe from me. But I don't know what it would be worth.

Ingineer said:

Question: If I were able to offer an additional upgrade level for the EVSE to a selectable 20A, would it be worth it?

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I for one would love it! However how do you intend to make it selectable? One of the things I really like about the mod currently is that there are no external modifications to the case of the unit.

Would it be possible to make it 15a for 120v and 20a for 240v? For me at least this would negate the need for an external selector. I can wish can't I?

What is your cost for the current mod and the turn around time? My car will be available in three weeks. I don't have an idea what the 20 amp mod would be worth as I don't know what I would recieve from the Feds as an offset toward a EVSE if I installed it. Anyone know how this works?

fotajoye said:

What is your cost for the current mod and the turn around time? My car will be available in three weeks. I don't have an idea what the 20 amp mod would be worth as I don't know what I would recieve from the Feds as an offset toward a EVSE if I installed it. Anyone know how this works?

Click to expand...

It was mentioned to be about $200. If you tried to get a credit you possibly could get it on the cost of the mod and electrical work.

Ingineer said:

All the components in the EVSE are rated to 20A, so this is possible w/o any additional hardware modifications. The Leaf would only pull ~16A on 240v, but it might pull more on 120v if permitted so that would be a reason to go over 16A.

Click to expand...

Your wording puzzles me, but isn't it true that 20A components should never be used for more than 16A continuous? Besides, I've never heard of any 120v outlet for more than 20A. So please explain what you mean by the LEAF pulling more than 16A at 120v. I guess you might mean short-term 120v charging - if that is even meaningful.

AFAIK, the L1 EVSE as shipped is limited to 12A at 120v. Since I have installed a dedicated 20A 120v circuit at home for charging my LEAF I would be quite interested in a 16A 120v mod.

What I really want, though, is a second L1 EVSE with a NEMA 5-20 plug on it that the LEAF can pull 16A from, no switch needed. I would keep that plugged in at home, and leave the 12A Nissan-supplied EVSE in the back of the car for emergency charging. I'd be willing to spend $400 for one of those.

Ray

On 240 Volts, the LEAF's charger won't pull more than 16 Amps, so the portable EVSE's components would handle the load easily. I'd be surprised if it would pull more than that on 120V power as well, but that would have to be tested. Modifying the L1 EVSE to supply 16A at 240V would make it perform exactly like the L2 AV unit, so I would very much like that upgrade. Note that I'm only talking about the current 3.3 kW LEAF charger. Things change considerably if/when a higher power charger becomes available in the LEAF.

For 120V operation, there MUST be a way to limit the current, since the usual outlet in the USA is rated 15A at 120V. I can't see any way other than a switch to make that selection. One of the reasons that the L1 EVSE is included with the LEAF is that Nissan understood that emergency or opportunity charging is a necessity. The L1 EVSE needs to work with virtually any available 120V outlet.

-Karl

planet4ever said:

Besides, I've never heard of any 120v outlet for more than 20A.

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Just an FYI ... RV Park 30amp services are TT-30 on 120V.

kolmstead said:

On 240 Volts, the LEAF's charger won't pull more than 16 Amps, so the portable EVSE's components would handle the load easily. I'd be surprised if it would pull more than that on 120V power as well, but that would have to be tested. Modifying the L1 EVSE to supply 16A at 240V would make it perform exactly like the L2 AV unit, so I would very much like that upgrade. Note that I'm only talking about the current 3.3 kW LEAF charger. Things change considerably if/when a higher power charger becomes available in the LEAF.

For 120V operation, there MUST be a way to limit the current, since the usual outlet in the USA is rated 15A at 120V. I can't see any way other than a switch to make that selection. One of the reasons that the L1 EVSE is included with the LEAF is that Nissan understood that emergency or opportunity charging is a necessity. The L1 EVSE needs to work with virtually any available 120V outlet.

-Karl

Click to expand...

In the past EV people had to know the circuit capacity or have a way to adjust the draw on the charger when unknown. Some chargers has a dial and some EVs had a switch to limit for a 15A circuit. Most commercial outlets are 20A. I would suspect the LEAF charger can operate at 16 or even higher on 120V.

With the present 16-amp charger in the LEAF:
For a portable 120v unit, it makes sense to retain a 12a option to use for long-duration charging from a 15a breaker, but a 16a option for use on a 20a breaker would also be useful.
Adding the 16a option for 240v operation would be great, allowing (almost **) maximum use of the car's charger.

** There is some indication that the LEAF's charger might NOT draw a full 15.8 (or so) amps if only offered 16 amps, but will pull it if offered 17a or greater. See the load current vs. Control Pilot graph posted recently. The person who geneated the graph should know.

With a 32-amp charger in the "future" LEAF:
A 20a setting would be useful.

Main Question:
How would the "user-selection" be done?

The sensing of AC voltage to auto-switch from 12a to 16a is one solution that does not require a user input.

Just switching the firmware from 12a (20% duty cycle) to another fixed setting is simple, once one does the rather LARGE job of recovering the firmware program, de-compiling it, making sense of it, and discovering how the duty cycle of the PWM is controlled. This is NOT a small effort.

If one wants 2 (or 3) selectable Max-Amps settings, one has to add a "user input", and change the firmware ... substantially. Relatively easy to do IF one had the original source code, but a BIG job otherwise.

Then, the actual user-input, to avoid integrity issues with the case, could be optical, or magnetic ... but again a non-trivial job. Drilling a hole and adding a waterproof push-button is another possibility.

-------
Another (maybe/perhaps) Option:
The SPX plug-in, easily "portable", L1/L2 (universal voltage), 32a EVSE with "Field Adjustable" Max Current settings up to 32 amps would appear to be compelling, IF it ever appears, and has a reasonable price. Also, it appears to have a Reset button that COULD be used as a user-input for Max-Current setting. BUT, the Field Adjustible feature might not survive, or might require special equipment and not be a simple in-use setting.

Ingineer said:

Question: If I were able to offer an additional upgrade level for the EVSE to a selectable 20A, would it be worth it?

I did some more digging, and I believe with some time investment I could update the unit's software such that we could add a user selectable current. (up to 20A)

All the components in the EVSE are rated to 20A, so this is possible w/o any additional hardware modifications. The Leaf would only pull ~16A on 240v, but it might pull more on 120v if permitted so that would be a reason to go over 16A. (I'll have to test this)

The time investment would be significant, so wanted to gauge interest. If you are interested, what would it be worth to you?

Click to expand...

I would pay $250 for just the switchable Amperage upgrade (assuming a 16A selection is provided).
I would pay $350 for both (240V & selectable Amps).

A proper 15A circuit will withstand 15A indefinitely, which is why it's called a 15A circuit. The reason for derating down to 12A is because not all circuits are dedicated, and thus may have other loads in use on them. Based on personal experience I'd say well over half of all 120V outlets found these days are on 20A circuits. Probably all 240V circuits found will be on at least a 20A dedicated circuit.

I think 12A, 15A, and 20A make the most sense to offer. I don't see the point of a 16A mode.

What I'm considering is you plug the EVSE into the wall, then connect the J-plug to the car. At this point it's in 12A default mode. The "Ready" LED will be solid as in a stock EVSE. If you hit the release button for a second (or unplug the J-plug from the car, then reconnect it), it will advance to 15A mode which is signified by the ready LED flashing at about 2 flashes per second. After a brief delay the car will now begin charging at 15A. If you repeat the button cycle again then you will be in 20A mode, which will be a faster ready LED flash of about 4 times per second. A final repeat of the cycle will land you back in 12A mode.

Easy-peezy and no switches or other hardware mods needed. For safety, If the EVSE loses power it will default to the 12A position. This is so if you trip someone's breaker, hopefully then it will not re-trip and you can still charge when power is restored.

Since the microcontroller has flash, I could even add more user-programmable functions, simply by using a paperclip to bridge the two small holes in the J-plug, then using the latch switch to select modes, etc. There really is no limit... Say if you wanted the unit to default to 15A instead of 12A or have the first mode be 8A instead of 12A. This could all be done by morse-code style button clicks.

Gary is right; it's a lot of work to take on this level of reverse-engineering, so I'm not going to attempt it unless there is decent interest.

-Phil

Ingineer said:

A proper 15A circuit will withstand 15A indefinitely, which is why it's called a 15A circuit. The reason for derating down to 12A is because not all circuits are dedicated, and thus may have other loads in use on them.

Click to expand...

I thought the reason they went with 12A is because the EVSE is a continuous load and would be calculated using the 125% rule which comes out to 15A.

evdriver: folks using kill a watt have been reporting 11.5 to 12A using L1 EVSE. Have you seen reports of higher currents?

ingineer: I don't know how you are going to keep track of feedback, but here's my vote: I'd like 16A capability at both voltages. Regarding price, I paid about $830 for the AV EVSE, so $300 for your modification, giving me a portable L2 EVSE sounds like a good deal to me. Selectable current would be somewhat useful, probably not worth a lot.

-Karl

Spies said:

Ingineer said:

A proper 15A circuit will withstand 15A indefinitely, which is why it's called a 15A circuit. The reason for derating down to 12A is because not all circuits are dedicated, and thus may have other loads in use on them.

Click to expand...

I thought the reason they went with 12A is because the EVSE is a continuous load and would be calculated using the 125% rule which comes out to 15A.

Click to expand...

I admit I haven't looked at the code lately, but the things I remember about the 125% "rule" were that it's a conductor and service equipment uprating for commercial continuous loads. They basically tell you where a continuous load is installed (note "installed") you need to size the service equipment and conductors at 125%. A portable "plug in" load is not affected by this rule specifically. Take this 1800 watt space heater as example, they sell these as plug-in units which pull 15A but have standard NEMA 5-15 plugs on them which will be used on 15A circuits, and a heater is definitely a continuous load.

While I admit it's not a good thing to load a circuit to it's full load, but if the design of the system were such that a 15A circuit could only handle 12A continuous, it would have a 12A breaker.

I thought that American circuit breakers SHOULD handle their rated current for roughly an hour or two, but MIGHT trip (after some hours) if a continuous load of more that 80% of their rating is used. Some 15-amp breakers MIGHT handle 15 amps for a "long" time, but are not required to do so.

I also heard that European Breakers will handle the rated current long term, in contrast to the USA circuit breaker specs.

Is that information on circuit breakers old, obsolete, or incorrect?

Signaling the EVSE to switch modes using the e-nozzle is a workable idea, but apparently some people have trouble just getting the J1772 plug to connect to their vehicle fully.

If one used the nozzle-release button (with the 2 small pins jumpered) to signal the EVSE to change Max-Amps, for better safety the EVSE should probably be modified to detect the no-diode condition so that the 120/240v AC is not delivered to the nozzle while "signaling".

Ingineer said:

A proper 15A circuit will withstand 15A indefinitely, which is why it's called a 15A circuit.

Click to expand...

That is not correct for standard circuit breakers, which include all residential circuit breakers. Loading at 100% for an extended period may trip the thermal mechanism. It is designed to hold indefinitely at 80% load or for at least 3 hours at 100% load, at an ambient temperature of 40C. So in practice it may hold indefinitely at higher loads for a typical ambient temperature, but there is no guarantee. Anything designed as a continuous load (over 3 hours) should only use 80% of the circuit ampacity.

Yours, Wayne