How to charge 2013 Leaf at 3.3 kw instead of 6.6 kw?

[Arvind]

I have a 2013 SV with a 6.6 kw on board charger, and just got a Chargepoint CT500 in the garage. Now I am noticing that I get much less range charging with the Chargepoint at 240v/6.6 kw than I do with trickle charging at 110v. Is this real? I am wondering if this is due the higher wattage, or voltage, or both.

Is it possible to make this 2013 Leaf charge at 3.3 kw instead of 6.6 kw but still at 240v? How?

 

[fooljoe]

Yes, it's possible to charge at a lower rate on 240v, but you can't make that adjustment from the car - you need an adjustable / lower power EVSE. Look into evseupgrade.

No, it's not possible that you get less range charging one way vs another. I assume what you refer to as "range" is the "Guess-O-Meter" (GOM) miles remaining display. Pay no attention to that. It varies based on how efficiently you most recently drove, so means nothing at all about how much range you will get on your next drive. Look for Tony's range chart and pay attention to your miles/kwh to get a real picture of how much range you can expect.

 

[planet4ever]

I have a 2013 SV with a 6.6 kw on board charger, and just got a Chargepoint CT500 in the garage. Now I am noticing that I get much less range charging with the Chargepoint at 240v/6.6 kw than I do with trickle charging at 110v. Is this real? I am wondering if this is due the higher wattage, or voltage, or both.

As fooljoe says, it is not real. You can't draw any legitimate conclusions from GOM values after charging. If you want to know how completely your battery is charged, look at the State of Charge display that the Trip Computer provides. It shows you a percentage inside an outline of a battery. Use the top left button in the group of four to the left of the steering wheel to page through the various displays in the bottom center of the dash. I'm willing to bet the charge display will provide results within 1% whether charging at 120v or 240v, and whether using a 16A 240v EVSE or a 30A 240v EVSE.

Ray

 

[MikeD]

Some 30a 240v EVSEs have the ability to be dialed back to charge at a lesser charge rate -- the Siemens VersaCharge is one that comes to mind (settable to 6, 7.5, 15, 22.5, and 30 amps) and also the Ecotality Blink (settable to 12, 16, 24, or 30 amps -- in this case, the setting means is not made public). In both of these cases, this rate is typically set at installation of the EVSE and is not readily changeable.

It is VERY important to know that both are required by their UL listing to ALWAYS be installed on a 40 amp circuit, i.e. they are NOT to be used on a circuit with less than 8 gauge wire or less than a 40a circuit breaker even if dialed back. I can only assume this is for safety reasons related to the possibility that the charging rate is dialed up later (either deliberately or inadvertently) to a charging rate the circuit cannot safely handle.

I think this "dial-back" capability is designed mainly for service that is not quite adequate if the EVSE is operated at full power, but it deemed OK is it is operated at the dialed-back power level. Another use is your situation, although I expect there will be times you will want to charge at the fastest rate.

 

[kentuckyleaf]

Some 30a 240v EVSEs have the ability to be dialed back to charge at a lesser charge rate -- the Siemens VersaCharge is one that comes to mind (settable to 6, 7.5, 15, 22.5, and 30 amps) and also the Ecotality Blink (settable to 12, 16, 24, or 30 amps -- in this case, the setting means is not made public). In both of these cases, this rate is typically set at installation of the EVSE and is not readily changeable.

It is VERY important to know that both are required by their UL listing to ALWAYS be installed on a 40 amp circuit, i.e. they are NOT to be used on a circuit with less than 8 gauge wire or less than a 40a circuit breaker even if dialed back. I can only assume this is for safety reasons related to the possibility that the charging rate is dialed up later (either deliberately or inadvertently) to a charging rate the circuit cannot safely handle.

I think this "dial-back" capability is designed mainly for service that is not quite adequate if the EVSE is operated at full power, but it deemed OK is it is operated at the dialed-back power level. Another use is your situation, although I expect there will be times you will want to charge at the fastest rate.

Question here about the UL listing you mention. If you dial a 30A EVSE back to say 20A, and use a 30A breaker with 8 AWG wire, that wouldn't really be a problem would it? I can see that keeping things at 8 AWG is a good idea, but why the 40A breaker?

 

[MikeD]

kentuckyleaf: You ask a good question. Perhaps the underlying principle is to not unnecessarily risk stressing (overheating) circuit components -- not even the circuit breaker. But I really don't know the underlying reasons.

As far as the prevailing code is concerned, perhaps this is answered by the general 2011 NEC Article 210.23 Branch Circuits -- Permissible Loads: "In no case shall the load exceed the branch-circuit ampere rating. An individual branch circuit shall be permitted to supply any load for which it is rated."

Also Article 210.3 Branch Circuits -- Rating: "Branch circuits recognized by this article shall be rated in accordance with the maximum permitted ampere rating or setting of the overcurrent device. ... Where conductors of higher ampacity are used for any reason, the ampere rating or setting of the specified overcurrent device shall determine the circuit rating."

I don't have a VersaCharge to look at, but I expect the label on it to read 208/240v and 30a (perhaps someone can verify this) and this how its "load" is determined, I believe.

Also from the Siemens VersaCharge (models VC30BLKR and VC30BLKB) Installation and Operations Manual (Document Number: 813540), page 12:

"A 2-pole, 40 A dedicated branch breaker is required for both cord-and-plug installation and hard wired installations."

I just assumed "required" meant "required by UL listing".

And on page 35:

"Recommended Branch Breaker -- 40 Ampere double pole for Permanent Installation (Siemens P/N Q240, B240) -- 40 Ampere double pole GFCI for Non-Permanent (Siemens P/N QF240)"

I take "Recommended" in context to mean if you have a compatible Siemens breaker panel, but also recommending the (much more expensive!) GFCI breaker for safer cord-and-plug operation -- but it is not a UL listing requirement.

 

[kentuckyleaf]

MikeD

Thanks for the answer. In terms of codes and safety, I would ask the local inspector to answer this question. If you are pulling the circuit from a 50A subpanel, and you are using 20 amps of 240 from your subpanel for other uses, say outdoor lighting, you might want to limit a VersaCharge to 20 amps (and 30A breaker) even if it doesn't strictly meet NEC codes. Your local code inspector might grant you a variance for a 30A breaker if you can properly demonstrate that the EVSE only draws 20A regardless of the label on the device. I would think this would echo the principle of installing ten 500W light fixtures with 28W CFL's on a 15 amp circuit. We know the fixtures could pull 5000W total if you used 500W bulbs, but since you intend to use only 280W total, the ten 500W fixtures really are not a problem. If someone later decides to replace your CFL's with 500W bulbs, the breaker trips, no fire, no sparks, just a tripped breaker (understand that I'm not suggesting codes or an inspector would allow installing this many lights on one circuit, just that it would not be electrically hazardous) On the other hand, the inspector could ask that you simply use a 20A EVSE, and skip the VersaCharge.

Regardless, if you use a 30A breaker, 8 AWG wire, and the VersaCharger is limited to 20A, in no way would this be hazardous. If somehow the VersaCharger reset itself to 30A, the worst thing that would happen is the breaker trips.

I could see where someone that was overly cautious might use a 25A breaker on a 30A EVSE if they have a 2011 or 2012 Leaf in order to protect the Leaf, not the EVSE. If for some reason your 3.3Kw charger in the Leaf exceeds 25A, the breaker trips.

What the NEC code does provide is consistency. When an electrical engineer with a quazi code compliant (but electrically safe) home sells their home, the electrical systems need to meet code. That is why my EVSE is on a 40A circuit, even though the Leaf draws maybe 16A. I could have used a 25A breaker on the 8AWG wire, and just replaced it with a 40A breaker when I moved, but since I do plan on moving at some point, might as well meet codes during the install. Even though we understand that a 25A breaker and 10 AWG wire (6 foot pigtail, not run in walls) to a EVSE charging 16A Leaf would be safe, that doesn't mean that it is a "best practice" when meeting code takes exactly the same time, just a few $$ more in material, and my EVSE is also 6.6WK ready!

 

[MikeD]

kentuckyleaf: It is unclear to me what the safety risk is in the situation you mention. BTW I did find this NEC article:

Article 422.10(A) Appliances -- Installation -- Branch-Circuit Rating -- Individual Circuits: "The rating of an individual branch circuit shall not be less than the marked rating of the appliance...[or] for an appliance that is a continuous load ... not less than 125 percent of the marked rating...".

and

Article 110.3(B) Requirements for Electrical Installations -- Installation and Use: "Listed or labelled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.".

Just because the safety risks are unstated and unclear doesn't mean it's OK to ignore clearly stated installation instructions. It may very well mean that I lack the experience, knowledge, and imagination to appreciate certain (subtle?) dangers.

Maybe the reason that the 40a breaker is required is not so much because of safety issues but because they wanted to reduce the possibility of breaker tripping to an absolute minimum because it otherwise risks damage to the EVSE and/or EV as opposed to a normal controlled charging shutdown. There does seem to be evidence that abrupt EVSE shutdown can cause charger (diode?) damage.

 

[vsiev]

I believe the versacharger requires 40a circuit (input) but outputs 30a. If you dialed down the output (20a), I believe the input will still need more amps (~30a) to output the 20a you want. So regardless, I would go with a 8 gauge circuit and 40a breaker since using a 30a breaker could trip the breaker most of the time.

http://w3.usa.siemens.com/powerdistribution/us/en/product-portfolio/electricvehicle/versicharge/Pages/versicharge.aspx" onclick="window.open(this.href);return false;

 

[TomT]

There is something else going on. There should be no detectable difference in range. By the way, it is 6.0 Kw charger, not 6.6...

I have a 2013 SV with a 6.6 kw on board charger, and just got a Chargepoint CT500 in the garage. Now I am noticing that I get much less range charging with the Chargepoint at 240v/6.6 kw than I do with trickle charging at 110v. Is this real? I am wondering if this is due the higher wattage, or voltage, or both.

 

[kentuckyleaf]

There is something else going on. There should be no detectable difference in range. By the way, it is 6.0 Kw charger, not 6.6...

And yet Nissan is still telling us it is a 6.6Kw. From their website, Today (edit, removed extra carriage returns, otherwise, copy and paste from Nissan website):

2013 NISSAN LEAF® SV
As low as$24,320Net value after federal tax savings*
107 Horsepower
129/102 city/hwy MPGe*
5 Seats / 4 Doors

Features:
•Includes S features plus:
•Nissan Navigation System [*]
•CARWINGS® [*]
•16" Aluminum-alloy wheels
•6.6 kW Onboard Charger

Hopefully you can understand the confusion over the 6.0 - 6.6Kw statements. Do we believe Nissan, or not? If they are lying (for the past several months), can't we sue them?

 

[kentuckyleaf]

kentuckyleaf: It is unclear to me what the safety risk is in the situation you mention. BTW I did find this NEC article:

Article 422.10(A) Appliances -- Installation -- Branch-Circuit Rating -- Individual Circuits: "The rating of an individual branch circuit shall not be less than the marked rating of the appliance...[or] for an appliance that is a continuous load ... not less than 125 percent of the marked rating...".

and

Article 110.3(B) Requirements for Electrical Installations -- Installation and Use: "Listed or labelled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.".

Just because the safety risks are unstated and unclear doesn't mean it's OK to ignore clearly stated installation instructions. It may very well mean that I lack the experience, knowledge, and imagination to appreciate certain (subtle?) dangers.

Maybe the reason that the 40a breaker is required is not so much because of safety issues but because they wanted to reduce the possibility of breaker tripping to an absolute minimum because it otherwise risks damage to the EVSE and/or EV as opposed to a normal controlled charging shutdown. There does seem to be evidence that abrupt EVSE shutdown can cause charger (diode?) damage.

And I agree with you completely. Recommending that someone with zero electrical background try to decode why a national electrical code is what it is, is a bad plan! On the other hand, if you understand that the Leaf's 3.3Kw charger, at continuous load draws ~16 amps (metered) is roughly 64% load on a 25A circuit, and that meets code for a continuous load. The Leaf is the appliance, not the cable and relays you connect to the Leaf. The EVSE itself draws practically no load from circuit. No matter what the code states, a 2011 or 2012 Leaf will have no problems on a 25 amp circuit. Plug in your 2013, with the 6.6Kw charger (let's assume for a minute that Nissan is correct, it is 6.6Kw) and you can draw 27.5A continuous. Now you are tripping breakers, making branch circuits hot (assuming 10 AWG on a 30A breaker), and you no longer meet code, assuming you allow the car to draw all 30 amps. The VersaCharger can tell the car to draw less than 30A, but there is a chance that the car doesn't listen properly and takes all 6.6Kw. If you stick with 40A wiring (6 or 8AWG, depends on length of the run) and a 30 amp breaker, if the communications fail and the car takes all 30 amps, the breaker trips. Wires don't get warm or anything, electrically it is safe, but as a practically, you don't want the breaker to trip, and it might very well hurt the car (due to a bad design that hopefully has been fully resolved in the 2013)

This gets back to why the code is what it is. Code states that a home EVSE is installed on a 40A branch circuit. The EVSE manufacturer and the auto manufacturer understand that 30A is all they can supply the car, so everyone makes the car and the EVSE to meet the code. No matter what car you plug in to the EVSE, it works, houses don't burn down, breakers don't trip. Everyone is the same. You move out, the next owner moves in, they don't need to worry about your experimental physics project, your home meets code. People like me, and maybe you, and of course many others on here, have a strong electrical background. I work with 480v 3 phase every work day, or some days 36KVDC at 6A (created from 480V 3Phase). I know what a Jesus Stick is, and how to use it.

So yes, absolutely stick to the letter of the code, it exists for some very good reasons.

 

[QueenBee]

This gets back to why the code is what it is. Code states that a home EVSE is installed on a 40A branch circuit.

Could you reference where NEC requires that home EVSEs be installed on 40 amp branch circuits?

 

[smkettner]

Leviton 160 will get you charging at 3.3 kW
evseupgrade.com will also provide a solution.

 

[DaveinOlyWA]

There is something else going on. There should be no detectable difference in range. By the way, it is 6.0 Kw charger, not 6.6...

And yet Nissan is still telling us it is a 6.6Kw. From their website, Today (edit, removed extra carriage returns, otherwise, copy and paste from Nissan website):

2013 NISSAN LEAF® SV
As low as$24,320Net value after federal tax savings*
107 Horsepower
129/102 city/hwy MPGe*
5 Seats / 4 Doors

Features:
•Includes S features plus:
•Nissan Navigation System [*]
•CARWINGS® [*]
•16" Aluminum-alloy wheels
•6.6 kW Onboard Charger

Hopefully you can understand the confusion over the 6.0 - 6.6Kw statements. Do we believe Nissan, or not? If they are lying (for the past several months), can't we sue them?

it is confusing (trying to clear that one up on Bay Area FB ) especially when the first charger was a 3.8 but input to battery was 3.3 and everyone called it a 3.3

now we have a 6.6 that inputs 6.0 so if we keep the same parameters as the first then its a 6.0 charger. either way, not really important. we have other fish to catch here

 

[Arvind]

As fooljoe says, it is not real. You can't draw any legitimate conclusions from GOM values after charging. If you want to know how completely your battery is charged, look at the State of Charge display that the Trip Computer provides. It shows you a percentage inside an outline of a battery. Use the top left button in the group of four to the left of the steering wheel to page through the various displays in the bottom center of the dash. I'm willing to bet the charge display will provide results within 1% whether charging at 120v or 240v, and whether using a 16A 240v EVSE or a 30A 240v EVSE.

Ray

OK, I will start monitoring SOC% and report back. Currently my GOM reading in miles matches SOC% to within +/-1 and has been like that for days with a 4.9 mi/kwh average. My commute is totally predictable, same route 5-6 days a week, and I am driving very conservatively in B ECO mode.

 

[TomT]

Nissan also claimed - and still does in many arenas - a 100 mile range for the Leaf... :lol:

The old charger was 3.8 Kw INPUT and 3.3 Kw OUTPUT.
The new charger is 6.6 Kw INPUT but 6.0 Kw OUTPUT...

There are playing somewhat loose and fancy free with the numbers...

There is something else going on. There should be no detectable difference in range. By the way, it is 6.0 Kw charger, not 6.6...

And yet Nissan is still telling us it is a 6.6Kw. From their website, Today (edit, removed extra carriage returns, otherwise, copy and paste from Nissan website):

 

[TomT]

I don't know the exact reference number in the NEC but the code states that the continuous current on a leg can not exceed 80% of it's breaker rating. Thus, the next breaker step up from 30 amps is 40 amps which allows 32 amps continuous... If the EVSE was internally set to allow a lower charging current - say 20 amps - it could then be legally be used on a smaller size wire and breaker than 40 amps (30 amps in this example as that is the next highest common breaker size)...

This gets back to why the code is what it is. Code states that a home EVSE is installed on a 40A branch circuit.

Could you reference where NEC requires that home EVSEs be installed on 40 amp branch circuits?

 

[kentuckyleaf]

This gets back to why the code is what it is. Code states that a home EVSE is installed on a 40A branch circuit.

Could you reference where NEC requires that home EVSEs be installed on 40 amp branch circuits?

I believe code (NEC 625) simply states 125% rating for continuous load. I do recall reading a requirement for a 40A circuit for residential EVSE, but it may well have been a local code. I'd spend time to google it, but my wife thinks I should be working in the yard, and she's getting mad that I'm on the computer.

 

[QueenBee]

I don't know the exact reference number in the NEC but the code states that the continuous current on a leg can not exceed 80% of it's breaker rating. Thus, the next breaker step up from 30 amps is 40 amps which allows 32 amps continuous... If the EVSE was internally set to allow a lower charging current - say 20 amps - it could then be legally be used on a smaller size wire and breaker than 40 amps (30 amps in this example as that is the next highest common breaker size)...

This gets back to why the code is what it is. Code states that a home EVSE is installed on a 40A branch circuit.

Could you reference where NEC requires that home EVSEs be installed on 40 amp branch circuits?

Correct but that doesn't mean "code states that a" 16 amp "home EVSE is installed on a 40A branch circuit."