Surprise: No Level-2 High charging for LEAF? 15A maximum!

[planet4ever]

If one buys the L3 DC option and the onboard charger can handle it's 50KW, why is level 2 so limited?

There is your misunderstanding, right there. The onboard charger does not handle L3 charging. The primary purpose of the charger is to convert AC current to DC so it can be used to charge the battery. The onboard charger is a little guy that can handle a (relatively) little bit of AC current. The L3 charger is outside the car, and it is a big hulking piece of machinery with major cooling requirements. The DC port bypasses the onboard charger, and goes straight to the "Battery Management System" which is the final gatekeeper for all forms of charging.

On the question of 3.3kW vs. 6.6kW, here is what the LEAF website says under charging FAQs:

Q: Will it plug into a regular household outlet?
A: It will charge on a regular 110/120V 20-Amp dedicated outlet. This is considered a "trickle charge," which means it would charge at a slower rate. For home charging, we recommend a home charging dock on a dedicated 220/240V, 40A circuit.
Q: How long does it take to charge?
A: Most people will charge it like a cell phone overnight at home. A full charge will take 8h on a 220/240V home charging station. A 480V quick-charging capability will eventually be available in many markets once a standard is set.

Nary a mention of four-hour charging on 240v.

 

[LTLFTcomposite]

Looks to me like Nissan is doing everything they can to keep the charging rates low until they see how the batteries hold up.

 

[EVDRIVER]

Looks to me like Nissan is doing everything they can to keep the charging rates low until they see how the batteries hold up.

If the Leaf would have issues with even 7.2kw charging then the pack is junk, period. If they were concerned about charging issues there would be NO L3 port on the car. This is purely a cost cutting decision.

 

[ttweed]

I will certainly get the heavier wiring sorted out to have 30A to the Blink charger, but I'm still disappointed in the 3.3kW L2 charge limit.

Do we have a choice in this if we are in the EV project? I have not seen exactly how my installation is spec'd out--those details seem to be between Ecotality and the contractor, and have not been shared with me. I have no idea what gauge wire is going to be pulled for the circuit to the EVSE or what size breaker will be installed. Does anyone know the spec for sure? I would hope that if the Blink unit is programmable for 30 amps max. that the installation will be "future-proofed" with a 40-amp breaker and large enough wire gauge to support max. service levels, even if the Leaf isn't capable of drawing max. power from it at this point, and the unit is initially programmed to deliver power at a lesser level. This seems the only prudent and safe way to install it, but I could also see that if Ecotality owns/controls the equipment, they might "cheap-out" for economic reasons on the installation.

Am I being paranoid?
TT

 

[DarkStar]

Does anyone know the spec for sure?

From BlinkNetwork.com (http://blinknetwork.com/media/kit/Blink%20L2%20Wall%20Mount%20Charger.pdf):

Input Voltage: 208 VAC to 240 VAC +/- 10%
Input Phase: Single
Frequency: 50/60 Hz
Input Current: 30 Amps (maximum); 12A, 16A, 24A available
Breaker Size: 40 Amps; settings at 15A/20A/30A available
Output Voltage: 208 VAC - 240 VAC +/- 10%
Output Phase: Single
Pilot: SAE J1772-compliant
Connector/Cable: SAE J1772-compliant; UL-rated at 30A maximum
Cable Length: 18 feet (estimated)
Exterior Dimensions: Wall Mount: 18” W x 22” H x 5-9/16” D; Cord Mount: 18” Diameter
Temperature Rating: -22o F (-30o C) to +122o F (+50o C)
Enclosure: NEMA Type 3R; sun-and-heat-resistant
Mounting: Wall-mount or pedestal

When the electrical contractor came out to my house to see if I qualified, he stated that they would be going with 40 amp service to the unit with 8 gauge Romex.

 

[aleph5]

The Blink charger installed by Ecotality is programmable:
http://www.blinknetwork.com/media/kit/Blink%20L2%20Wall%20Mount%20Charger.pdf

Input Current: 30A max , 12A, 16A, 24A available
Breaker size: 40A with settings for 15A/20A/30A

If I understood the Leviton guy correctly, the first Leviton EVSE to be introduced (and maybe their ONLY one out by the end of the year!--hint, hint for tax credit) will be the 16A version.

 

[EVDRIVER]

The Blink charger installed by Ecotality is programmable:
http://www.blinknetwork.com/media/kit/Blink%20L2%20Wall%20Mount%20Charger.pdf

Input Current: 30A max , 12A, 16A, 24A available
Breaker size: 40A with settings for 15A/20A/30A

If I understood the Leviton guy correctly, the first Leviton EVSE to be introduced (and maybe their ONLY one out by the end of the year!--hint, hint for tax credit) will be the 16A version.

Pointless for a Leaf, there are other ways to get the credit in the tax year and buy the EVSE in the next. No thanks on anything less than 6.6 min.

 

[aleph5]

Pointless for a Leaf, there are other ways to get the credit in the tax year and buy the EVSE in the next...

How would one do that?

 

[smkettner]

IMO anything above 16a is pointless for Leaf.
I am really looking for the Leviton at a lower price than AV before year end.

 

[DeaneG]

IMO anything above 16a is pointless for Leaf.
I am really looking for the Leviton at a lower price than AV before year end.

+1 for me, given that there will be no 24A Leviton unit to plug into my existing 30A dryer breaker. I'll conduct my personal EV experiment as cheaply as possible (except for the 3kW solar PV system ).

 

[planet4ever]

Oops, deleted. I misread.

 

[pgrovetom]

Yes, it is possible to build your own L2 EVSE, not even too difficult if you have a good design and the right skills.

Currently, there seems to be no "public" designs available, so one would need to find sufficient EE skills to create a good, safe design (non-trivial job).

I've looked at the problem and it's not terribly difficult. Everything attached to the AC path can be UL approved with only the pilot signal and controller connection to the pilot lead custom. It can be opto-isolated and powered by a UL approved +5v/+12V power lump plugged into the 120V outlet.

But, it would still be illegal to use it for residential charging, since the NEC says it must be "listed". Presumably that means tested by a lab like UL.

There is some question as to whether the rules/laws regarding testing and NEC code compliance apply to a homeowner hobbyist. If one intends to sell a product, then UL or similar listing is required. Any hobbyist can legally build an electronic device that plugs into AC power without certification if it's for personal use. As far as the NEC code, a homeowner may have NEC compliant 240V 15A circuits installed or 2 out of phase 120V outlets installed both with GFCI circuits and then plug the EVSE into them, similar to the Leviton approach. Of course anyone not thoroughly familiar with the safety and design issues should not attempt this. For someone with extensive design background, it's actually extremely simple.

The design of a L3 "charger" system is much more difficult, since a LOT of power is involved. It is not even clear to me if the complete "communication" protocol is in the public domain.

My suggestion, unless you have considerable skills in the "power supply" area: do not even consider trying a L3 BIY project.

The L3 is quite another beast and I agree. Its not clear to me how the L3 actually works. Most Lithium charging systems clamp and monitor each cell so its not clear how an external charger would understand that cell level problem without extensive signaling. I would love to see how they plan on implementing an external charger or is it just an external rectifier to move rectification heat away from the EV, charger and batteries. Does anyone actually know how exactly the L3 is structured? Does it just supply a DC voltage and the charger is in the car or is the charging also external? If the charging is external, how does it clamp and monitor each cell?

 

[garygid]

For the L2 internal power supply, +12v and -12v are needed for the
Control Pilot signal. I would use a "universal" (100v to 260v AC input)
power supply so that one EVSE design could be run on 120v or 240v.

-----
The L3 system has a high-power external DC power supply.
Presumably it is current-controlled, where the BMS in the car monitors
battery cells, and then a L3 "charging controller" in the car tells the external
"power supply" how much current to send in at any given moment.

The car would be the only part of the system that would know what kind
of a charging (current) profile was desired (best) for the battery pack.
At some point the BMS would detect near-full, and the car would ask that
the external-sourced current be reduced. When full, or done, the
current request would be reduced to zero.

I do not know what commands and information the DC QC specifications
define, but it would seem that the car MUST be able to control the
charge-rate profile, for the safety of the car's battery pack.

 

[mxp]

Could someone explain how does the Leaf achieve fast charging (with the L3 option) to 80% capacity in 30 minutes with 440V electric chargers given the internal system is only rated at 3.3kW ?

Thanks.

 

[evnow]

Could someone explain how does the Leaf achieve fast charging (with the L3 option) to 80% capacity in 30 minutes with 440V electric chargers given the internal system is only rated at 3.3kW ?

External DC charger will be used, bypassing internal AC charger.

 

[EVDRIVER]

My suggestion, unless you have considerable skills in the "power supply" area: do not even consider trying a L3 BIY project.[/quote]

The L3 is quite another beast and I agree. Its not clear to me how the L3 actually works. Most Lithium charging systems clamp and monitor each cell so its not clear how an external charger would understand that cell level problem without extensive signaling. I would love to see how they plan on implementing an external charger or is it just an external rectifier to move rectification heat away from the EV, charger and batteries. Does anyone actually know how exactly the L3 is structured? Does it just supply a DC voltage and the charger is in the car or is the charging also external? If the charging is external, how does it clamp and monitor each cell?[/quote]


The same as L2, the L2 charger does not have connections to all the modules it gets basic info from the BMS to stop or throttle back. L3 will have a communication to the external charger that will do the same, perhaps CAN but not sure at this point. It would be the same principal, what changes is where the charger is located.

 

[LTLFTcomposite]

I'm still soaking up the information from this forum.

I suppose the reason I'm surprised is that the EV Project estimator was saying they need to add a 30A or 40A breaker to my panel, and how there's little room.
It seems like adding a 15A or 20A load is simpler, especially since there's already one for the Solar Panels that's backfeed only. I'd rather sort out a subpanel for the *next* electric car if the LEAF isn't going to tap more than 15A.

It's also a bit misleading that Nissan sends out the Level info above when anyone asks "how long does it take to charge". If Level2 High is not an option (ever), then that might be nice to point out.

But yeah, 3.3kW is what it is, and I should have known.

Adding a (15A or 20A) single pole breaker is only easier than adding a double pole breaker (of any rating) in the case where you only have one open slot. If you don't have two open slots it should be a fairly trivial matter to switch out some single pole breakers for tandem breakers, but the situation could be complicated if the panel has a lot of GFIs and arc fault breakers or doesn't support tandem breakers. There could also be some total load limits you could bump up against.

 

[LTLFTcomposite]

Looks to me like Nissan is doing everything they can to keep the charging rates low until they see how the batteries hold up.

If the Leaf would have issues with even 7.2kw charging then the pack is junk, period. If they were concerned about charging issues there would be NO L3 port on the car. This is purely a cost cutting decision.

I wouldn't be so sure.

Why did they decide to only offer the L3 charger on the SL model?

The goals appear to be:
1) minimize the charging rate on the batteries for most of the population
2) keep the number of units in the population that are using any fast charging small (but enough so you can gather stats on how they hold up
3) throw some extra $$$ in the warranty "kitty" for the ones that are doing fast charging

 

[planet4ever]

It's also a bit misleading that Nissan sends out the Level info above when anyone asks "how long does it take to charge". If Level2 High is not an option (ever), then that might be nice to point out.

This statement keeps bugging me. What information is Nissan sending out or has it sent out any time recently about Level2 high? I just now stumbled across a Q&A snapshot that I took from nissanusa.com/leaf-electric-car on Apr 22. It's the same basic story as I posted yesterday, except that they have now backed off from the claim of 16-18 hours at 110v:

Q: What is the estimated time for full charging with 110v, 220v and fast charge stations?
A: Starting from a depleted battery, 16-18 hours at 110V, 8 hours at 220V (depending on amperage), 26 minutes to 80% at a quick-charge station.

 

[EVDRIVER]

Looks to me like Nissan is doing everything they can to keep the charging rates low until they see how the batteries hold up.

If the Leaf would have issues with even 7.2kw charging then the pack is junk, period. If they were concerned about charging issues there would be NO L3 port on the car. This is purely a cost cutting decision.

I wouldn't be so sure.

Why did they decide to only offer the L3 charger on the SL model?

The goals appear to be:
1) minimize the charging rate on the batteries for most of the population
2) keep the number of units in the population that are using any fast charging small (but enough so you can gather stats on how they hold up
3) throw some extra $$$ in the warranty "kitty" for the ones that are doing fast charging

Car marketing 101- it gets them to sell more SL models and ONLY SL will be wired initially per the nissan Rep. 7.2 kw charging won't hurt the pack, if it did then L3 would destroy it shortly, there is a HUGE difference in heat on those two. Driving the car at a constant speed is harder on the pack then 7.2 kw charging. Most Leaf orders are SL so that blows the "limit" the fast charging option. 7.2 kw is only 30A, thats low current considering hill climbs will pull closer to 200A plus.