Nissan Leaf Charger

[hausdok]

Last week I ran into a charger for a Nissan Leaf in a customer's garage. I'd never run into one before. I normally wouldn't have even looked at it, 'cuz such things are outside the scope, but being the curious type I checked it out anyway. That's when I got really cornfoozed.

A 40-amp two-pole breaker protects it and a #6 copper cable runs to a 50-amp plug on the wall of the garage which that charger is plugged into. Then there's the label; if I'm reading this thing right, it draws 30 amps and is supposed to have a maximum fuse of 30 amps (see below).

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So, I thought by using a 40-amp breaker they'd over-fused the thing. To confirm that, I came home and googled the thing on the net and got to the the site. The site says that the input current is 40-amps and that a 40-amp 2-pole breaker is appropriate.????

Any of you electrical whizzes want to help dispel my cornfoosiosition?

ONE TEAM -ONE FIGHT!!!

Mike

[John Kogel]

I can only say what I see there, not being an expert or whizz.

The Rating and Output appear to be saying the same thing - the charger puts out 30 amps of charging current.

If the instruction manual calls for a 40 amp supply current, then that is what it needs to produce that 30 amps. A dead battery pack might draw 30 amps from the charger, but the breaker won't blow and the cable won't overheat because that house wiring is rated at 40 amps, for safety. I think.

I wonder why they don't tell us that the output is direct current, which it needs to be AFAIK. Converting AC to DC has losses, which I will let Marc explain. So for an output of 30 amps DC the charger needs to recieve more than 30 amps AC.

[Richard Moore]

I can only say what I see there, not being an expert or whizz.

The Rating and Output appear to be saying the same thing - the charger puts out 30 amps of charging current.

If the instruction manual calls for a 40 amp supply current, then that is what it needs to produce that 30 amps. A dead battery pack might draw 30 amps from the charger, but the breaker won't blow and the cable won't overheat because that house wiring is rated at 40 amps, for safety. I think.

I wonder why they don't tell us that the output is direct current, which it needs to be AFAIK. Converting AC to DC has losses, which I will let Marc explain. So for an output of 30 amps DC the charger needs to recieve more than 30 amps AC.

OK, so just last Friday I installed one of these myself, after a bunch of research. Not the Leaf one but a Clipper Creek LCS-25. Let me take John's last comment first. The wall unit is miss-named. It's a charging station, not a charger. The output is 240 volts AC, not DC. The actual charger is in the car, the unit on the wall is effectively a large on/off switch for the AC current. It has some other functions, but perhaps the primary one is to prevent the AC current just sitting in the cord until it it is plugged in and the car communicates with the box.

The Leaf station is a 7.2 KW unit, capable of putting out a full 30 amps should the vehicle charger be capable of taking it. A 30-amp circuit/breaker would be too close to that, hence the 40-amp requirement. The Leaf car actually has a 6.6 KW on-board charger. The car I just bought for the wife is a plug-in hybrid, a Ford C-Max Energi with a smaller battery pack, but still capable of 21+ miles on battery alone (my record in the first few days we have had it is 22.4 before the hybrid engine had to start). It's perfect for her daily commute but also has an unlimited range on gas. Like a Chevy Volt.

Anyway, the C-Max only has a 3.3 KW on-board charger (on 240 volt), about 14-amps. The Clipper creek can put out as much as 4.8 KW but our car will only demand the 3.3. Takes just over 2 hours to charge from empty as opposed to 7+ if I used the included 120-volt "charger". The LCS-25 calls for a 25-amp circuit for hard wire or a 30-amp for their plug-in model (same unit but portable). I could also plug into a Leaf or other larger charging station but, again, the draw is dependent on the charger demand in the car and the charge time would be the same. On the other hand, a Leaf could use my charging station but would be restricted by the station to 4.8 kw even though it can take 6.6. I don't know every in and out, but I do know that's how it works.

[hausdok]

Hi Richard,

Thanks for your response. I agree that it is called a charging station but since I first posted this I found their installation operations manual online and in there they repeatedly refer to it as a charger. There is a bit of a difference; your car is a hybrid; the leaf is 100% electric. No gas motor; no on-board charging system. I specifically asked him whether it had the ability to charge itself like a Prius or other hybrid - it doesn't. In fact, the wife returned hom and rolled the car up behind me while I was standing in front of the house and I never heard it. I asked the guy if it use any gas and he said it didn't.

I eventually found the answer in the manual. It says the output from the "charger" is 30Amps but that a 2-pole 40-amp breaker is necessary.

Guess I should have done some more research.

ONE TEAM - ONE FIGHT!!!

Mike

[Richard Moore]

1st of all...Not Kurt. Yeah, they all call them chargers, but they really are just "stations". Whether it's the Leaf, Volt or the C-Max Energi, the actual charger (transformer?) is on-board. Not sure about the Tesla with their huge battery bank and their fast charge system. I am fully aware of the difference between BEVs (Leaf, Tesla, Focus Electric), PHEVs (Volt, Ford Energis, Prius Plug-in) and all the regular Hybrids. There is a C-max that is just a Hybrid, but the Energi model is a plug-in hybrid which can operate just like the Leaf, albeit for shorter distances, in all battery mode using household voltage to charge the larger section of the battery. The ICE (internal combustion engine) in a plug-in hybrid like the C-Max Energi spends a lot of the first few miles after a charge just sitting there as a heavy lump of metal at the front of the car, but it is instantly available to be used in addition to the big battery pack for extra oomph if needed or wanted. It's actually a fun drive.

A plug-in hybrid is a compromise between an all electric car like the Leaf and a regular hybrid. More limited miles on battery alone but without the range anxiety that comes from having no back-up. I looked at them all and settled on the Ford as something we could both enjoy, and use for trips short and long. Frankly, it makes no sense at all financially, but the wife wanted to go electric for her commute. We have a "vehicle" that gets less than 2 miles to the gallon so perhaps this is making up for that a bit?

[Marc]

The air conditioner in my house is in two parts, inside and outside. If I don't make it clear whether I'm referring to the evaporator section or condenser section, confusion may result.

I think the situation with these plug-in and hybrid cars is similar in that the manufacturer doesn't make it clear that the charger is in two parts. The stationary section which is simply the interface in the wall for the AC supply and the converter/control section which is in the car.

It makes sense that the car manufacturer would put the converter/charge section in the car so that wherever you go, if you're in a bind, need a charge and there's a 240V AC supply available, you have a chance to charge it - if you can figure out how to make the connection.

The conversion into DC current doesn't come into play until we get inside the car.

Pretty much what Richard said. An single electrical load should not exceed 80% of the rating of the supply circuit.

Marc

[Scottpat]

The Leaf is made down the road from me and was first introduced in Nashville, I see several a day. We also have charging stations at most of the Cracker Barrels around the state. Nissan put them in for free! They have about a 70 mile range on a charge, then you are dead in the middle of the road stinking to high heaven...

[hausdok]

Sorry Richard,

Please note time of response? Was getting foggy-brained. Well, nah, that's not true - I'm always foggy brained. I guess you could say I was on the verge of falling asleep sitting at my desk.

Anyway, the manual answered the question, though John K. had answered it looooong before that.

This thing was configured as a plug-in but I see in the manual that they can hard wire them. What's next - a friggin' windmill?

ONE TEAM - ONE FIGHT!!!

Mike