Increase from 3.3kW to 6.6 kW sooner rather than later

[Randy]

Not sure if I'll get an answer, but I sent an email to Brian Verprauskus at Nissan last night to get more information about this issue. Brian is the person whose name is on the pdf or ppt Nissan Leaf files that many of us have downloaded as he makes various presentations around the country. You'll recall that his charging chart in that document shows the 6.6kW and 3.3kW charging rates for Level 2 charging. So I asked him if that capability would be available in the first generation Leaf models...

If it's not going to be included, it seems to me that Nissan should stop touting the charging time with those 4 hour 6.6kW numbers...The fact that they have them in there offer me at least some hope that it might be included. Twice I asked the Nissan Chat folks this question, and twice they told me that as long as the EVSE has the higher rated electrical connection and breaker, they will support 6.6kW charging. I know that sometimes the chat folks don't have the technical capability to answer questions like that, but they answered the question both times. And there have been plenty of other questions I've asked that they've declined to answer until more information was available...

For me, I could probably live with the 3.3kW charging, but I'm anticipating going to a Time of Use rate that has cheap power for 5 hours (midnight to 5am). So I could probably live with just charging at 3.3kW during that period, but will have to plug in every day and settle for less than a full charge sometimes if I want to stay within that 5 hour window...

 

[darelldd]

This is not a Euro-spec car.

I never meant to imply that it was. Only that the charging system was.

All cars have different specs, components and engines for various markets, there is even more reason to have 6.6 in Europe as 240 is standard and the euro ev I owned had a switch for low power charging. This is not about outlets. It's not about more, it's actually a sweet spot and very practical, more is 12kw or the level 3.

I'm only offering up what the Nissan folks have shared with me during pre-production with the 3.3 was already locked in. They knew it was a mistake... but too late.

 

[Juiced]

I am a veteran of the MINI E program. One of the unanticipated delays in getting the MINI E program started was the home charger installation process. The logistics of getting a 240 volt 40 amp circuit to the garage of an existing home turned out to be very challenging in many cases. Does your home have extra capacity to accommodate the 240V / 40A electrical load? Wiring for a 240V / 40A circuit requires larger wire and conduit sizes than exist in most american homes. Think about where your existing electric meter and main panel is located in relationship to your garage. Now what will it take to get from point A to point B? In our case it was a 24 inch deep trench through the back yard from one end of our home to the garage on the other end. City jurisdictions in Southern California had a different interpretations of what was required to comply with the building code, simply because this was a new product that they were not familiar with. My guess in that Nissan is opting for the smaller charging system with the 20 amp load to avoid the in-home infrastructure headaches as the Leaf brand launches as well as the cost of those infrastructure upgrades. At the end of the day it is worth it however, as I have not been to a gas station in over a year.

 

[garygid]

Even if the car only uses the 3.3 kW charging now, it is probably cost-efficient (in most cases) to install the 40-amp service now.

Usually, unless the existing panel or service cannot handle the 40-amp breaker, the cost is almost the same for a 40-amp install and a 20-amp install.

 

[DeaneG]

Usually, unless the existing panel or service cannot handle the 40-amp breaker..

Do you have any idea how to judge that? I have 200-amp service which I imagine should be OK, but wasn't sure if there was an upper limit on the total ampere capacity of all the installed breakers in the panel.

 

[mitch672]

Thats not really true. I have a 60AMP subpanel in my garage, it's absolutley not going to be able to handle a 40A load for an EV charger, plus it's on an 8KW backup generator (off the main panel).

I am installing a "CSED" (Combined Service Electrical Device), so I can run a new 100A line to my garage, that is located "before" the generator transfer switch, none of this is inexpensive, although the parts are inexpensive, the whole project, is expensive when labor is added in. I am trenching myself, and "assisting" the electrician [which costs twice as much when you "help" ], it's still going to cost at least $1500-$2000 (just upgrading my 150A service to 200A alone is expensive, the aluminmum wire alone is over $4/foot)

CSED: http://www.lowes.com/pd_79498-296-RC816F200C_0_?zipCode=02368&ddkey=http%3ASearchCatalogDisplay&newSearch=true&firstReferURL=http%3A%2F%2Fwww.lowes.com%2Fpd_79498-296-RC816F200C_0_%3FnewSearch%3Dtrue%26catalogId%3D10051%26productId%3D1196613%26Ntt%3Drc816f200c%2B%26N%3D0%26langId%3D-1%26Ns%3Dp_product_price%257C0%26storeId%3D10151%26Ntk%3Di_products%26ddkey%3Dhttp%3ASearchCatalogDisplay&catalogId=10051&productId=1196613&findStoreErrorURL=StoreLocatorDisplayView&selectedLocalStoreBeanArray=%5Bcom.lowes.commerce.storelocator.beans.LocatorStoreBean%4034f6e67d%2C+com.lowes.commerce.storelocator.beans.LocatorStoreBean%403427267d%2C+com.lowes.commerce.storelocator.beans.LocatorStoreBean%4034c6a67d%2C+com.lowes.commerce.storelocator.beans.LocatorStoreBean%4030afa67d%2C+com.lowes.commerce.storelocator.beans.LocatorStoreBean%402b6e67d%5D&Ntt=rc816f200c+&N=0&URL=TopCategoriesDisplayView&langId=-1&Ns=p_product_price%7C0&storeId=10151&Ntk=i_products

 

[EVDRIVER]

This is not a Euro-spec car.

I never meant to imply that it was. Only that the charging system was.

All cars have different specs, components and engines for various markets, there is even more reason to have 6.6 in Europe as 240 is standard and the euro ev I owned had a switch for low power charging. This is not about outlets. It's not about more, it's actually a sweet spot and very practical, more is 12kw or the level 3.

I'm only offering up what the Nissan folks have shared with me during pre-production with the 3.3 was already locked in. They knew it was a mistake... but too late.

If they are only using 3.3kw then I may wait and keep my options open. At 65 MPH with no AC they leaf is likely to get about 65 miles of range or less, 50 with loads, hills and passengers so the need for a larger charger is key for some. If the leaf ends up being 3500 lbs it is no surprise why the range numbers are what they are. Some people discount weight and the impact on range, it is a very big factor in real-world driving.

 

[garygid]

Apparently there is no simple way, like adding up all the breakers and dividing by two.

It appears that, most likely, each load type, and when it might be ON, is considered to arrive at some indication of maximum symultaneous loading.

Biggest loads, pool, heating, A/C, EV charging, spa, cooking, dryer, etc. would be fairly typical to consider first. Heating and A/C would rarely be on at the same time.

 

[IceRaven]

Does the 6.6 kW charger make any difference in the recharge time for a standard(US) outlet (like the ones used to power some electric lawnmowers and block heater) compared to the initial 3.3kW?

 

[EVDRIVER]

Does the 6.6 kW charger make any difference in the recharge time for a standard(US) outlet (like the ones used to power some electric lawnmowers and block heater) compared to the initial 3.3kW?

It will cut the time in half, for the 3.3kw charger but if you use a standard outlet you are not going to get half of the 3.3kw output. 3.3kw is only available with 240 volts. I would estimate charging the Leaf with the standard cord at about 20 hours, 8 with the 3.3kw charger and about half that if there were a 6.6kw charger.

 

[DaveEV]

Do you have any idea how to judge that? I have 200-amp service which I imagine should be OK, but wasn't sure if there was an upper limit on the total ampere capacity of all the installed breakers in the panel.

As Gary said, it's not as easy as adding up all your breakers and applying a simple calculation factor.

There's a couple formulas that the NEC uses for calculating this (usually called a "Load Service Calculation"), to determine the minimum service power that should be supplied to your house to avoid accidentally tripping the main breaker.

One version goes something like this, assuming 2000 sqft house:

Lighting loads - dwelling size (sqft) * 3: 2000*3: 6000 VA
Small appliance (kitchen): 3000 VA
Laundry: 1500 VA
Range: 10000 VA
Dishwasher: 800VA
Disposal: 800VA
Microwave: 1700VA
Dryer: 6000VA
Subtotal: 29800VA
AC/heat: 5000VA

So the first 10k VA of the subtotal is counted at 100%, then the rest (20k) is counted at 40%.
Any heating/cooling loads are counted at 100%.

So we end up with:
10000VA + 7920VA + 5000VA = 22920VA

Divide that by 240V to get the minimum size of your main breaker/feed = 95.5A - would round up to 100A

Any hard-wired appliances have to be added to the load calculation sub-total (like the disposal, dishwasher, microwave, dryer, etc), so if you add a 6600VA car charger, that would add 11000VA of load (11A@240V) to your house if they count it at 40% so now you'd need a 110A main feed minimum. If they count it at 100% (which they might since it could be running at full load 4-8 hours/day), you'd need to have your service upgraded to 125A main feed minimum.

Anyway, once you have 100A service, typically most will simply upgrade to 200A - sizes in between are not that common from what I understand (125A and 150A are possible but not common) and typically the cost difference between upgrading to one of the various sizes is not significant meaning upgrading from 100A to 150A is not much different than upgrading from 100A to 200A. The only case where it might be significant is if your service wires are underground and sized for 150A so only going to 150A might save you the cost of having to dig a new trench out to the street to run new conduit/wire.

That's just an example using information I learned when researching upgrading my 100A underground service to something larger... One quote I got to upgrade to 200A was $4000-$6000 because of the need to dig a new trench, lay new conduit and run larger wires from the utility "handhole" to my house. One case where having above ground service feed greatly simplifies things.

 

[Bicster]

I guess if they have to, they can disconnect my dryer outlet. I have a gas dryer. I can't imagine what it would cost to upgrade my 200A service!

 

[sjfotos]

I guess if they have to, they can disconnect my dryer outlet. I have a gas dryer. I can't imagine what it would cost to upgrade my 200A service!

Last time I upgraded my half of a Duplex about 3 years ago, from 100 to 200 AMP service, including re-wiring in several rooms, it was about $4,500. This is two story unit with one bathroom, a kitchen, living room, dining room and 3 small bedrooms.

 

[muus]

To answer IceRaven's question:

Does the 6.6 kW charger make any difference in the recharge time for a standard(US) outlet (like the ones used to power some electric lawnmowers and block heater) compared to the initial 3.3kW?

If by standard outlet you mean 120v, then no it makes no difference. The Leaf will only draw 1.4kW from a "standard" 120v outlet, which is the maximum permitted from a 15A plug. However, charging a completely dead battery could take up to 19 hours.

 

[planet4ever]

If by standard outlet you mean 120v, then no it makes no difference. The Leaf will only draw 1.4kW from a "standard" 120v outlet, which is the maximum permitted from a 15A plug. However, charging a completely dead battery could take up to 19 hours.

True, and that limit is going to be enforced even if you happen to plug into 20A circuit, because neither the car nor the charging cable know the size of the wire inside your wall or the amperage of your circuit breaker.

Two slight quibbles: (1) Hopefully you will never have a "completely dead" battery, because if you do, its lifetime will have been severely compromised. Because of that, the charging controller in the Leaf never lets the battery go completely dead. What muus meant was a battery that was down to minimum usable charge. (2) Nissan has in the past said 20 hours, rather than 19, to recharge completely, and more recently I have been seeing 22 hours. I think this is because charging slows when the battery approaches maximum capacity. I would guess you could get to 95% capacity in 19 hours.

 

[househippie]

I just read through this thread and was wondering whether the design is to extend battery life. I remember reading somewhere the Level 3 fast charge will decrease battery life, so it stands to reason that charging at 3.3kW versus 6.6kW would be gentler on the battery.

 

[EVDRIVER]

I just read through this thread and was wondering whether the design is to extend battery life. I remember reading somewhere the Level 3 fast charge will decrease battery life, so it stands to reason that charging at 3.3kW versus 6.6kW would be gentler on the battery.

That's not the issue, it was cost. Expect a 6.6kw charger to be implemented. There is a significant difference in heat and current between 6.6kw level 2 charging and level 3. The difference between 3.3 and 6.6 is not going to impact the pack, 27 amps is nothing on a pack that size vs the potential 125A from the level 3.

 

[kahlepj]

This was all news to me the other day. I even got on to chat with Nissan yesterday and they are still talking about Level 2 (high) charging being capable of 6.6 kW and 4 hours to recharge. This even though Nissan has clearly indicated that is not a current option. They also told me not to think about upgrading the charger to 6.6 using a third party because it would void the warranty. This seems very short sighted on Nissan's part.

Ford has now made it clear that the Focus will come out of the shoot with a 6.6 kW charger and made it a major factor in their advertising campaign. I would hope that increases the urgency of this issue for Nissan That linked with the news I got this week that I won't see my Leaf until April is making me rethink a lot of this. Maybe leasing is the way to go, turn in the car when I can get a better charger.

My house will easily support the higher charging rates at night when I'm not using any other appliance and I bet just about everyone else in this discussion is in the same boat. The only time you have to worry about the capacity of your panel would be during the day. Then you might have to charge at a lower rate.

 

[planet4ever]

Sure, but why do you care? Doesn't your car usually sit at home for at least 7 hours at night? The only argument for 6.6 I've heard which sounds valid to me is faster charging when someplace away from home.

 

[EVDRIVER]

Sure, but why do you care? Doesn't your car usually sit at home for at least 7 hours at night? The only argument for 6.6 I've heard which sounds valid to me is faster charging when someplace away from home.

Primarily but also grabbing shorter super off peak times for some. In some cases one will also need a quicker charge at home.