Does the Leaf have a radiator?

Wire cooling in the LEAF sounds like BS (incorrect information) to me.

It might be difficult for newcomers to sort out what is true?

Message board is more conversation than encyclopedia

garygid said:

Wire cooling in the LEAF sounds like BS (incorrect information) to me.

It might be difficult for newcomers to sort out what is true?

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As long as manufacturers hire PR firms that spout utter nonsense people will think it's true. EVs are very simple machines and are all built about the same, there is no magic tech, no radical cooling deviation and no miracle motor that doubles range. When these people and the Nissan CS do this type of thing it explains why cords are called chargers and cables have water cooling. Non-tech people should just stop making things up, because someone can change their air cleaner on their car it does not make them a mechanic and reading all the hype on ABG or forums does not make one an EV expert. The problem with forums is that people unknowingly post inaccurate info or things they read on the web. It's easy to get accurate EV info via books and the web, just skip the articles from people who are "experts" because the drove one and wrote a review, we see that every day.

palmermd said:

EVDRIVER said:

I do need to clarify to avoid confusion about one wire, the wires to the usb port are likely cooled, a computer expert told me that is typical on high-speed connections. I'm sure the CAN bus is as well for speed, surely a loop to the inverter cooler.

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I think he was talking about this wire cooling (rack) that comes with the accessory NA721 which is the solar cooking option.

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You always know what I'm thinking! It's been difficult to get things straight since my coiled EVSE cord gave me a bad dose of EMF and burst into flames from heat while just sitting on the ground! I also have a detached retina from looking directly into an LED tail light too long, don't do that! I'm also going to put a bank of fans on the front of the car to generate power to charge the pack when I drive on the freeway

It appears that the charger is also cooled. In a video at work it shows coolant lines under the car going into the bottom of the charger.

wgs1912 said:

It appears that the charger is also cooled. In a video at work it shows coolant lines under the car going into the bottom of the charger.

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That is very common on factory cooled EVs with water cooled inverters and motors. This allows chargers to be placed in confined spaces and when charging there is no loud fan noise since the radiator fan is not needed and the pump is silent.

To clear everything up:

there are two seperate glycol based systems in the Nissan Leaf.
#1 HV cooling system. This is exactly as it sounds. Think ICE, but in place of the actual engine you have the traction motor, invertor, DC-DC convertor, on-board charger, etc.

There are two coolant pumps that are run in unision, albeit at different speeds (to prevent harmonics/NVH issues). Both pumps always run unless there is a pump failure, in which case the remaining pump is run at 100% duty cycle to prevent HV overtemperature conditions.
There is a traditional radiator, though it is a cross-flow style... and appears to be a triple pass unit!
The actual HV battery is air cooled.

#2 cabin heater system. This consists of a coolant pump and the actual "heater assembly". There is no heat exchanger (radiator) for the heating system.

Both systems have seperate swirl pots (burp tanks, call it what you like - with pressure caps), but share an overflow bottle.

Both systems use the "super dooper" new Nissan LLC - this is blue (not the old school green) and comes premixed in a 50/50 solution from Nissan. Both systems are claimed to be "lifetime" - worded proplery - maintanence free.

The A/C system is exactly like Altima Hybrid - uses a HV compressor and has a traditional system layout.


Hope that clears everything up!

-n-

there is absolutely no wire cooling of any sort in this vehicle. that is obsurd and i would mope around all day if i had to deal with diagnosing that nonsense!!

drees said:

DarkStar said:

The difference in the Leaf is that the coolant isn't under pressure like a traditional engine radiator system, thus it is very unlikely to develop a leak. Sure, you'll have to glance it, but it shouldn't need anything more than annual maintenance.

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You probably don't need to do more than check the fluid levels more than a couple times a year.

Coolant these days typically lasts at least 3-years 36k miles before a change - and usually a lot longer. For example, on the Prius, you only need to change the engine and inverter coolant after 10 years / 100,000 miles and every 5 years / 50,000 miles after the first one.

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I believe the service manual said 125,000 for first fluid change and 75,000 thereafter.
Forgot the related time interval.

Excellent info! Thanks!

I am curious about the design of the cabin heater, and why it benefits from having an indirect (coolant) stage. Why not just resistive heat in the cabin airflow directly? Seems like it would take longer to heat fluid than just glow into a fan.

The A/C compressor.. runs directly of HV battery pack power?

GroundLoop said:

Excellent info! Thanks!

I am curious about the design of the cabin heater, and why it benefits from having an indirect (coolant) stage. Why not just resistive heat in the cabin airflow directly? Seems like it would take longer to heat fluid than just glow into a fan.

The A/C compressor.. runs directly of HV battery pack power?

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Heater is safer as water coolant instead of coil , also provides more consistent temp and holds some heat when the heating elemnt is de activated
This is good news

kmp647 said:

GroundLoop said:

Excellent info! Thanks!

I am curious about the design of the cabin heater, and why it benefits from having an indirect (coolant) stage. Why not just resistive heat in the cabin airflow directly? Seems like it would take longer to heat fluid than just glow into a fan.

The A/C compressor.. runs directly of HV battery pack power?

Click to expand...

Heater is safer as water coolant instead of coil , also provides more consistent temp and holds some heat when the heating elemnt is de activated
This is good news

Click to expand...

I see. A thermal buffer, of sorts. Makes sense if you're trying to keep hot wires out of the passenger area.

Do you know if the heater is also HV powered?

Also, do you know if a service tool (Nissan Consult-II?) is able to adjust the convenience options, like unlocking all the doors together?

GroundLoop said:

kmp647 said:

GroundLoop said:

Excellent info! Thanks!

I am curious about the design of the cabin heater, and why it benefits from having an indirect (coolant) stage. Why not just resistive heat in the cabin airflow directly? Seems like it would take longer to heat fluid than just glow into a fan.

The A/C compressor.. runs directly of HV battery pack power?

Click to expand...

Heater is safer as water coolant instead of coil , also provides more consistent temp and holds some heat when the heating elemnt is de activated
This is good news

Click to expand...

I see. A thermal buffer, of sorts. Makes sense if you're trying to keep hot wires out of the passenger area.

Do you know if the heater is also HV powered?

Also, do you know if a service tool (Nissan Consult-II?) is able to adjust the convenience options, like unlocking all the doors together?

Click to expand...

Heating water is far less efficient and a traditional heater is perfectly safe when sealed in an enclosure. It will run off pack voltage as it would be ridiculous to use 12V, that would mean something like 300 amps. Heaters that use water based systems also have a lag time. AC also off pack.

I agree, a hot water heater seems inefficient, unless one is heating a "thermal mass" of water while plugged in.

Perhaps there is also a hot water tap for that early-morning refill of hot chocolate?

Going over the owners manual, I'm a bit mystified at the coolant system(s) design.

I find reference to the 7 quart capacity cooling system and water pump. Seems like a lot of mass and hardware.

Is the only purpose of this system to cool the charger and inverter?

Is this system in any way connected to the cabin heater?

Is there a separate coolant ("heat-ant") fluid reservoir for climate control, entirely separate from the coolant system?

Sure seems like the heat stored in the thermal mass of 7 quarts of coolant could come in handy on a cold day.

edatoakrun said:

Is the only purpose of this system to cool the charger and inverter?
Is this system in any way connected to the cabin heater?
Is there a separate coolant ("heat-ant") fluid reservoir for climate control, entirely separate from the coolant system?

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Yes (and maybe the motor, but probably just the charger and inverter)
No
Yes (heat is electrictric, but apparently goes through some water)

Last answer edited - I do not know what I'm talking about and should only answer things I am sure about

THE heater uses water to conduct heat to the cabin thru a typical heater core

the heater element is resistive coil in a tank under hood

it uses a pump, resivoir and heater core and is a seperate system from the inverter-charger-motor coolant circuit.

"it uses a pump, resivoir and heater core and is a seperate system from the inverter-charger-motor coolant circuit."

And there is no heat exchange between the two systems?

edatoakrun said:

And there is no heat exchange between the two systems?

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Would be a shame if there wasn't, IMHO. That's a very simple thing to do and it's potentially "free" heating. Although exactly how much heat the motor/inverter throws off is questionable, if it's enough that they went with liquid cooling in the first place then it's enough to provide some degree cabin heating/defrost air.
=Smidge=

We believe the primary coolant cools the Inverter and Electrical Motor.

Some conjecture about it cooling the hump-located Charger, but I doubt it ... but it could. If it does, the coolant pump (and perhaps radiator fan) would need to come on, at least when the charger was getting "too" hot.

The heater fluid system appears to be entirely separate from the motor/inverter coolant system.

In cold weather, when you need heat in the cabin, the main coolant system might be quite cold, so of no use in heating the cabin.

garygid said:

Some conjecture about it cooling the hump-located Charger, but I doubt it ... but it could. If it does, the coolant pump (and perhaps radiator fan) would need to come on, at least when the charger was getting "too" hot.

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I believe I read in the manual that while charging a fan could start and/or you could hear some sort of pump. I remember thinking "oh the charger must be water cooled" and being a bit surprised at it.

In cold weather, when you need heat in the cabin, the main coolant system might be quite cold, so of no use in heating the cabin.

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Good point, no need to artificially heat up the rest of the system just to heat the cabin..not to mention how much more thermal mass the motor/inverter cooling circuit has which would require a lot more energy to make warm... At first I couldn't understand why they wouldn't take advantage of the heat produced by the system for cabin cooling, but when you get into it, it does create more problems than you would initially think.