Leaf Disclosure and trickle charging

[dvdmon]

Ok, so I'm supposed to be going to pick up my new Leaf tomorrow. The dealer sent me the disclosure to read over so I wouldn't have to do it at the dealership. I passed it onto my wife before looking at it, and unfortunately she freaked out a bit and is thinking we need to hire an electrician before we buy the car now. Here's the topic that got her:

Trickle Charge. Although not recommended for regular use,a dedicated 120 outlet maybe used with the supplied charging
cord or an SAE J1 772 complaint cord. Charging by this method will take much 10 ger than 240V charging. Warning: to protect
against electrical hazard, serious personal injury or death: (1) Do not plug in the c arging cord until it is inspected by a licensed
electrician to confirm that the electrical circuit can accept a continuous 12 amp raw and (2) Do not use this charging cord in
structures more than 40 years old, or structures using fuse-based circuit protection, nd use only with an electrical circuit protected
by a dedicated circuit breaker See your owner's manualfor additional warnings.

My father-in-law lives with us and he's our handyman and he looked at the garage. Apparently everything in the garage, as well as the room above the garage which holds my office, is on one line. It's a 110V line. We have a stand-up freezer in the garage which he thinks at least temporarily could get hooked up via extension cord to an outlet in the main part of the house. Our house is not 40 years, old, it's about 36 years old. Anyway, any thoughts? THis is the first I've heard of such concerns. I know this is a liability issue, but how serious is this, do we really need to be very careful? We have level-2 charging stations within a mile or two of hour house, and at my office, so we can always charge at these if we have to for the time being, but I was counting on using the line in the garage for the most part. I'd love to get an electrician to run a 240V line in there just for the car, and then get my charger upgraded via EVSEUgpgrade, but I think then we're talking another $600+ which we don't really have right now after our $2K downpayment. Anyway, if you have any insights on this, I'd love to hear them.

 

[TonyWilliams]

Where is you breaker box in relation to the garage? If its mounted on a wall shared by the garage (either inside or outside) it should NOT cost $600 to run a 40 amp circuit for 240 volt service.

 

[LeftieBiker]

Basically, it comes down to whether you have a 110-120 volt circuit that can safely charge the car. It doesn't actually have to have only the car on it, but if you are running both lights and power tools from the same circuit you'll be using on the car, you have a problem. If it's just lights and the car, replace the bulbs with LEDs or compact flourescents, and make sure you have a modern, plastic-covered, grounded cable, in good shape, supplying the garage. It doesn't have to be new, just in good condition and not overloaded. If that isn't going to work, it isn't expensive to have a single 120 volt circuit added if the service box is near the garage. If it is far away, look at how long and how difficult the cable run would be. Since it's the same kind of work to run a 220 volt cable (you do need two free breaker slots in the breaker box instead of one, though) it should only be slightly more expensive to run a 220 volt line. In that case, though, you'd also need to have your EVSE (the cable for the car) upgraded, for about $300, to run on 240. That would charge the car much faster. The cheapest solution is a dedicated 120 volt, 15 amp circuit added to the garage.

I'm charging from an older 120 volt outlet in my garage.

 

[cwerdna]

FWIW, I've asked a bunch of times to no avail for someone to inspect wiring in the Bay Area at http://www.mynissanleaf.com/viewtopic.php?p=305748#p305748.." onclick="window.open(this.href);return false;.

I would at least make sure the 120 volt outlet is on a dedicated 15 amp circuit that is not loaded (or only very lightly loaded) when the car's charging. Also, check to make sure you don't have aluminum wiring. See http://www.mynissanleaf.com/viewtopic.php?f=26&t=10887" onclick="window.open(this.href);return false;.

I checked the wiring at the houses at both places where I might charge at and confirm the wiring at the outlet's not aluminum and the 15 amp circuit. Given my current situation and commute length, I will mostly be charging at work for free.

I would definitely monitor the outlet and area for unusual heating or smells when first charging.

 

[LeftieBiker]

FWIW, I have a Kill O Watt meter on my EVSE and it says the 2013 EVSE for my Leaf draws 11.4 amps.

 

[planet4ever]

Apparently everything in the garage, as well as the room above the garage which holds my office, is on one line.

Ouch! That doesn't sound good. At least if the house was built in the 70's I would expect that to be a 20A circuit, not 15A. I suggest two sanity checks: 1) What amperage is listed on the breaker switch? 2) Do the outlets have a T-shaped slot on one side? T-shaped slots should only be used on 20A circuits, and normally 20A circuits should have T-shaped slots.

We have a stand-up freezer in the garage which he thinks at least temporarily could get hooked up via extension cord to an outlet in the main part of the house.

He's right to focus on that. A freezer can start up at any time of the night, and it has a fairly high starting load. With everything else on that circuit I'm afraid you'd have a good chance of the breaker tripping if the freezer starts up while the car is charging. Then you end up with a warm freezer and a car that isn't charged.

I know this is a liability issue, but how serious is this, do we really need to be very careful?

I think it is more a matter of practicality than liability. Assuming the wire size is proper for the breaker (i.e. that some previous handyman hasn't decided to put in a 30A breaker, or something) the breaker should trip before there is any likelihood of a fire.

Ray

 

[LeftieBiker]

What I'm curious about is the insistence on not having a fuse box. There are fairly modern fuse boxes out there that were still being installed after circuit breakers made their way into the home wiring scene. There are also circuit breakers that will screw in as replacements for fuses...

 

[QueenBee]

What I'm curious about is the insistence on not having a fuse box. There are fairly modern fuse boxes out there that were still being installed after circuit breakers made their way into the home wiring scene. There are also circuit breakers that will screw in as replacements for fuses...

But the vast majority are connected to old wiring. The other big issue is in the last six decades did any of those fuses blow and get replaced with the incorrect size for the wiring?

 

[clayton72]

Our society is so heavily dependent on electricity, it's a wonder basic safety isn't taught in grade school. Most houses have 20 amp circuits in kitchen and sometimes bathroom and garage. It'd save lives.

volts * amps = maximum watts per circuit. My house has 121 volts, on 15amp = maximum 1830 watt load. Most refrigerators and air conditioners run at <750 watts, but spike a heavy load to start and should have their own circuit. Microwaves and space heaters have a heavy load. Hair dryers of course.

3 things can happen when you overload a circuit... 1) the breaker trips 2) the circuit can overheat causing a catastrophic drop in resistance which leads to a fire 3) the starved device dies.

Anyone who's tried to use an power tool on a long thin power cord may have experienced that last. For me my first experience was an electric lawn mower on a couple 14 gauge, 100 foot extension cords.

For maximum performance and safety always underload circuits. 12 amps is a good place to stop on a 15 amp circuit. A cell phone charger isn't going to be an issue, but a fridge will. Avoid extension cords with all any load over 7 amps. The higher the load, the heavier and shorter the extension should be. At 12 amps, don't use an extension cord. I have 25 and 50 foot garden hose thick cords I might resort to in a pinch, but a car is a might thing to gamble.

If you have a 240v circuit put in, get an outlet installed and use an EVSE that you can plug in. Run 6 - 2 or 6 - 3 cable so you can plug in larger EVSE's in the future. Some go up to 70amps already. You don't want to have to call an electrician after your next vehicle purchase.

 

[dvdmon]

Ok, I just took myself at the breaker boxes and outlets. We have two. The right one has the stuff going to the garage. I took photos of the breakers and the outlets and put them up on my Dropbox account here:

https://www.dropbox.com/sh/03bbdabvfqujhnk/fpFyN9YCXt" onclick="window.open(this.href);return false;

We've always run the freezer since moving to this house, and I've been running at least two PC's (one of which is a desktop) in the room above the garage for a while with no issues. In addition to that, I've periodically ran an electric lawnmower and an electric leaf blowervac from the garage outlet, with no issues either.

Is the "150 Ampere" on the breakers essentially saying that they are 15 Amps?

 

[dvdmon]

Ok, I just took myself at the breaker boxes and outlets. We have two. The right one has the stuff going to the garage. I took photos of the breakers and the outlets and put them up on my Dropbox account here:

https://www.dropbox.com/sh/03bbdabvfqujhnk/fpFyN9YCXt" onclick="window.open(this.href);return false;

We've always run the freezer since moving to this house, and I've been running at least two PC's (one of which is a desktop) in the room above the garage for a while with no issues. In addition to that, I've periodically ran an electric lawnmower and an electric leaf blowervac from the garage outlet, with no issues either.

Is the "150 Ampere" on the breakers essentially saying that they are 15 Amps?

Ok, so, it looks like with DO have a 240V line going into the garage! We have an AC unit in the room above the garage and we looked and it has the T-shape outlet! (I just added a picture of the outlet to the dropbox folder) So I guess that won't be a huge deal to get it routed to somewhere in the garage?

As for the "150 Ampere" - my father-in-law says that is the total amount coming into the house. He also says that the 240V line is actually 2 120V lines tied together...

 

[Ingineer]

The last picture in your series shows a NEMA 6-20 outlet which is 240V at 20A. You can get your EVSE upgraded and charge your LEAF safely using this outlet needing only an adapter. The electrical code says to limit your draw to no more than 16A continuous for this type, but that will still charge your LEAF in under 7 hours.

You will need a NEMA 6-20 to either L6-20 or L6-30 depending on which upgrade you choose. I'd recommend the high-power version (L6-30 equipped) and you can always dial the amperage down to 16A if desired.

The cost is $287 plus shipping to have this done. We don't stock the NEMA 6-20 adapter, but we do sell bare pigtail cords and all you'd need is the plug end (available from your local hardware store). If you aren't comfortable installing the end, shoot us an email and we can help you out.

-Phil

 

[dvdmon]

The last picture in your series shows a NEMA 6-20 outlet which is 240V at 20A. You can get your EVSE upgraded and charge your LEAF safely using this outlet needing only an adapter. The electrical code says to limit your draw to no more than 16A continuous for this type, but that will still charge your LEAF in under 7 hours.

You will need a NEMA 6-20 to either L6-20 or L6-30 depending on which upgrade you choose. I'd recommend the high-power version (L6-30 equipped) and you can always dial the amperage down to 16A if desired.

The cost is $287 plus shipping to have this done. We don't stock the NEMA 6-20 adapter, but we do sell bare pigtail cords and all you'd need is the plug end (available from your local hardware store). If you aren't comfortable installing the end, shoot us an email and we can help you out.

-Phil

Thanks, Phil. I don't feel comfortable doing any wiring myself. Also, the outlet that I showed was the one in the room above the garage, so we can't use that for charging, but I thought it was good that this was in the same area so that we could just get someone to extend that into the garage itself and put a new outlet there. If that's the case, should it be the same type of outlet or if they are doing work anyway, would it make more sense to get a different type? Also, is it a lot harder to get an outlet put on the outside of the garage vs. the inside? And in general, what can I expect to pay for, ballpark, doing this kind of work? I just want to know so that if someone is charging me double what they should, I'll know they are ripping me off.

 

[Assaf]

Can anyone in the know chime in on why Nissan says "110V charging is not recommended on a regular basis?"

I thought that the slower and gentler the charging, the less impact on batter life, not so?

Or is it because they fear people's regular 110V circuits might be unreliable, old, etc. etc.?

I wonder.

 

[Levenkay]

Clayton's remarks are mostly correct, except for

3 things can happen when you overload a circuit... 1) the breaker trips 2) the circuit can overheat causing a catastrophic drop in resistance which leads to a fire 3) the starved device dies.

The potential for a mild thermal runaway arises from the fact that copper has a POSITIVE temperature coefficient of resistance. Overloading a circuit will tend to warm up the wires, which INCREASES their resistance, and, since the power dissipated in the wires is proportional to their resistance, tends to warm them still more. Generally, the effective resistance of the circuit's load swamps out the wiring resistance, so you just get a shifted equilibrium point, and things are only a problem if that results in the wires becoming so hot that they can ignite combustible materials, or maybe weaken their plastic insulation to a failure condition. There are some loads, though, that exhibit "constant power demand" tendencies. Devices with fancy power conversion will attempt to draw higher currents as the supplied voltage drops, and that can further aggravate the problem. Usually though, fancy powersupplies are designed to have "brownout limits" on the amount of extra current they'll try to draw to compensate. I imagine that an EV's on-board charger would respect the current limit as specified by the EVSE's control signal, though, and, in any case, there's supposed to be a current breaker in the supply circuit too.

 

[dgpcolorado]

Can anyone in the know chime in on why Nissan says "110V charging is not recommended on a regular basis?"

I thought that the slower and gentler the charging, the less impact on batter life, not so?

Or is it because they fear people's regular 110V circuits might be unreliable, old, etc. etc.?

I wonder.

That's easy: Nissan was/is concerned that very slow "trickle charging" would prove a nuisance and reduce the utility of the LEAF. For those who drive ten miles a day Level 1 charging can work fine. For those who drive more than fifty miles a day Level 1 charging would be a lot of trouble, although it can be done.

 

[Levenkay]

Can anyone in the know chime in on why Nissan says "110V charging is not recommended on a regular basis?"

I thought that the slower and gentler the charging, the less impact on batter life, not so?

Or is it because they fear people's regular 110V circuits might be unreliable, old, etc. etc.?

I wonder.

The lower charge rate ought to be less stressful to the battery, all right. Here are a few semi-plausible arguments for why 240V charging would be preferable, though. Most of them have been discussed on the forums before.

• You don't have to wait as long for the car to charge on 240V, and so can enjoy it more/more often. I imagine Nissan would prefer that any recommendation/discussion of the car you have with other parties would come from as satisfied a viewpoint as possible.
• Others have pointed out that there's a fixed power overhead involved in running/cooling the on-board charger. That fixed overhead diverts a larger fraction of the energy extracted from a 120VAC electrical service away from charging the battery, relative to the energy from a 240VAC supply. So the car's operating cost will be slightly higher on a 120V diet than on a 240V one. (See item "a").
• Assuming that you'd be using the Nissan-supplied portable EVSE to do the 120V charging, the business of unpacking and repacking the EVSE each day would quickly become wearisome (Again, see item "a"). Nissan has to assume that you'd still be carrying the portable EVSE in the car..
• Related to the above, the portable EVSE's connector would be undergoing a great many more connect/disconnect cycles, and its cables wound and unwound many times more often than Nissan expects. You could wear it out.
• This is pretty far-fetched, but there's a reasonable consensus that a LEAF's battery degrades as some complex function of many variables, including "total time spent in high-charge states". And an operating profile that involves significant daily recharges results in the battery being at higher levels of charge for longer periods of time when the total charge time itself is longer. (Note: this assumes that one is responsibly using an "end timer" to delay recharging until just before each day's use) Roseannadanna logic would caution that squirting higher recharge current through the battery has to be bad too, though, so who can say which is better?

 

[Assaf]

Thanks to both of you for your responses.

All explanations sound plausible, but none of them or even all of them combine do *not* IMHO rise to the level of the car maker writing black-on-white that they "do not recommend" using trickle-charging as the predominant mode. Unless some other evidence comes to light, this is not a truthful description of reality on the part of Nissan.

As to myself, I enjoy not having to spend >$2k on L2 apparatus to charge in front of our home (where we usually park), or having to inconveniently park it outside the garage in our back alley (where the installation would be cheaper).

We also rarely pack the EVSE into its original bag. It just stays in a big plastic container (together with its extension cord) near the front of the house, and gets stretched out to the street when we charge. Not a big deal.

Finally as to inefficiencies and overhead, in our experience the trickle charge time actually needed is usually some 20% shorter than what our car computer says, so it's quite efficient for our needs.

In short, I'm quite satisfied with trickle, and would prefer Nissan not to pre-emptively define what gives me enjoyment. They should focus on tips and full disclosure on practices that increase battery and EVSE life, and of course driving range, and leave the specific consumer choices to the consumer.

 

[dgpcolorado]

...Finally as to inefficiencies and overhead, in our experience the trickle charge time actually needed is usually some 20% shorter than what our car computer says, so it's quite efficient for our needs.

:?: Why you consider the charging finishing a bit early to be "efficient" is a puzzle. Efficiency of charging has to do with how much of the power coming from the wall gets to the battery. Charging at 120 Volts, 12 Amps, is about 75% efficient. Charging at 240 Volts, 16 Amps is about 86% efficient. Charging a 2013 model at 27.5 Amps would be a bit more efficient than that, as will charging to 80%, as opposed to 100%. (The reason has to do with the fixed overhead to charging the car, involving pumps, cooling and the like. Shorter charging time, less overhead.)

If you want to make the argument that the cost of the electricity wasted with Level 1 charging is small compared to the cost of installing a Level 2 charge station, then few would disagree. The advantages of Level 2 charging have to do with speed and convenience. If you don't need much charge each day and don't need to preheat the car in a very cold climate, then trickle charging will suffice, as you have found.

In short, I'm quite satisfied with trickle, and would prefer Nissan not to pre-emptively define what gives me enjoyment. They should focus on tips and full disclosure on practices that increase battery and EVSE life, and of course driving range, and leave the specific consumer choices to the consumer.

Consider the possibility that some people buy the LEAF, expecting to use it for a 50+ mile commute using the supplied trickle charge EVSE (because that's what Nissan includes with the car, right?). How happy are they going to be when they find that they charge all the time and still can't seem to fill up the car? Nissan expected that LEAF drivers would use the Level 2 charging for which the car was designed and which was likely to provide a more satisfying user experience. The Level 1 EVSE was provided for opportunity charging where Level 2 was unavailable and Nissan didn't want new LEAF owners to assume that the very very slow trickle charge EVSE was the only way they could charge the car.

If you manage ok with Level 1 charging fine. But knocking Nissan for recommending against it, for quite valid reasons, seems unwarranted.

 

[planet4ever]

All explanations sound plausible, but none of them or even all of them combine do *not* IMHO rise to the level of the car maker writing black-on-white that they "do not recommend" using trickle-charging as the predominant mode. Unless some other evidence comes to light, this is not a truthful description of reality on the part of Nissan.

I am not usually one for conspiracy theories, but I have long suspected that Nissan is required to say this by their contract with AeroVironment.

As to myself, I enjoy not having to spend >$2k on L2 apparatus to charge in front of our home (where we usually park)

That sounds like a great argument for the EVSE Upgrade. I, too, park and charge in front of the home, and always with my upgraded EVSE. It is plugged in to an outlet which is weather protected in an enclosure on the side of the garage. The outlet is behind our side fence, but most of the cable is looped on a hose rack outside the fence, ready for easy use at any time.

Ray