Heater Coolant Hot when Charging - Teakettle Syndrome

[smkettner]

Are the pumps running?

 

[EVDRIVER]

Are the pumps running?

I was wondering the same, easy to check.

 

[garygid]

Video the problem, Good Idea.

 

[starry]

I am not aware of any indicators for pump activity. I can only go by what I can feel and hear.
To quote myself: "I do hear pump motor noise as a faint hum." I feel fluid moving through the pressurized tubes. I cannot feel any vibration on the front pump, and the pump for the rear inverter/charger is not available for inspection, as far as I know.

 

[garygid]

Sounds like the car control is confused.
Consider re-booting the whole car before charging again.
(Remove -12v connection for about 5 minutes.)

 

[smkettner]

I am not aware of any indicators for pump activity. I can only go by what I can feel and hear.
To quote myself: "I do hear pump motor noise as a faint hum." I feel fluid moving through the pressurized tubes. I cannot feel any vibration on the front pump, and the pump for the rear inverter/charger is not available for inspection, as far as I know.

If fluid is boiling and pump is running then all piping or tubing should be very hot (240 to 270F?) to the touch all the way to the radiator and the radiator fan (I assume it has one) should be running.

 

[garygid]

I am doing a 16-hour L1 charge (from 25% SOC) to test a "normal" non-Updated "B" car's L1 charging behavior (with no extension cord, so the 120v supply will not be "too low" as it might be with a long, light-duty extension cord):

Observing the car at 6:15 (just after driving, parking, and starting to charge), 8:15, 10:20, 11:30, 2:20, 6:15 ...

All is well: The Heater reservoir is cold, the HV coolant reservoir is SLIGHTLY warm, the only sound is a "fluid pump" sound, fluid is flowing through the rubber hose just behind the upper edge of the radiator. No gurgle, burp, or bubble sounds of any kind.

 

[DarkStar]

I am doing a 16-hour L1 charge (from 25% SOC) to test a "normal" non-Updated "B" car's L1 charging behavior (with no extension cord, so the 120v supply will not be "too low" as it might be with a long, light-duty extension cord):

Observing the car at 6:15 (just after driving, parking, and starting to charge), 8:15, 10:20, 11:30, 2:20, 6:15 ...

All is well: The Heater reservoir is cold, the HV coolant reservoir is SLIGHTLY warm, the only sound is a "fluid pump" sound, fluid is flowing through the rubber hose just behind the upper edge of the radiator. No gurgle, burp, or bubble sounds of any kind.

This was the same as my experience on Friday when I did a 6 hour L1 charge. My fluid noise was definitely only coming from the pump though right underneath the HV coolant reservoir.

 

[Coffee_Slurry]

I am not aware of any indicators for pump activity. I can only go by what I can feel and hear.
To quote myself: "I do hear pump motor noise as a faint hum." I feel fluid moving through the pressurized tubes. I cannot feel any vibration on the front pump, and the pump for the rear inverter/charger is not available for inspection, as far as I know.

If fluid is boiling and pump is running then all piping or tubing should be very hot (240 to 270F?) to the touch all the way to the radiator and the radiator fan (I assume it has one) should be running.

Exactly.

"It ain't getting any hotter!" The fans should be running full-throttle, pump running, etc.
Boiling into overflow means it's exceeding the design range of the cooling system.

I suspect there's no circulation, or no fan. Something else could be amiss if the charger is shedding much more power than it should, and simply overtaxing the cooling system. If your fans were at full-speed, circulating the boiling fluid, then it's probably a power/efficiency failure in the system soaking up current. Keeping a few liters of water boiling is probably consuming hundreds of watts in itself. Check how much power (overall) is being used in a charge, and I suspect it's far over 20kWh.

In any case, I would expect the whole charging system to shut down if the coolant reaches boiling. It's surprising that it keeps generating heat.

 

[garygid]

Yep, the Service guys couldn't believe us either.
So, barring a miracle, it goes back to Service sometime soon.

I hope to run some tests today.

 

[garygid]

The Mystery Continues:

The HV cooling (of the inverter, motor, and charger) is not the source of the excess heat. The Heater coolant Reservoir is what heats up during charging, either L1 or L2.

This heating seems to come on within about 5 minutes of starting charging (one time I thought I heard the click of a relay), and the Heater Reservoir gets hotter and hotter, going from ambient of mid 80's to about 140 ºF in an hour and 180 or so in two hours ... and the heating continues. The heater system coolant does not appear to circulate, but the hot fluid seems to "well up" from lower down, much like a hot water geyser.

There is no heating or fan in the cabin, and the CC system is OFF. There is no heater timer set. For the most part the front radiator fans remain OFF (unless the HV coolant gets hot, which it did one time).

In a "normal" LEAF, even after 12 hours of charging, the Heater Reservoir remains cool, essentially nothing over ambient.

There seems to be the sound (a medium, slightly raspy sound) of "a pump" or something, but that is not the HV system pump (which makes a smooth low whir).

Maybe the Heater coolant pump is jammed and is overheating because it is ON for some strange reason?

 

[smkettner]

When it starts to overheat.... can you send a signal to preheat the car?
This would seem to put the system in normal operation and stop the overheat condition.

Then try the cycle over again.

 

[gbarry42]

The HV cooling (of the inverter, motor, and charger) is not the source of the excess heat. The Heater coolant Reservoir is what heats up during charging, either L1 or L2.

You don't suppose there's a heater in there, for wintertime operation? If so, it sounds like it is stuck on.

 

[Coffee_Slurry]

Wow, weird.

I'm with smkettner... run the heater! See if the same hot fluid starts circulating and cooling off. Then turn the heater off and see if it gets unconfused.

If the cabin heater is running (unintentionally), and the pump/circ is not operating, I would be very worried that the heating element (resistive heater) would run without bounds -- boiling away the heater fluid and running far over temp. Worst case, it could start a fire.

 

[DaveinOlyWA]

Checked mine this morning after 12 hours of charging and I can hear water circulating. I squeezed the hose and could feel and hear the water running. But there is very minimal warmth felt and it was in 50's last night so very warm.

Being to wonder if what u have is not all that far from normal. I am guessing. That my car will get warmer as summer approaches as well.

Another thing I thought about ttyl.g was seeing if more warmth is evident when charging to 100%.


This morning I barely hit 80%

 

[IBELEAF]

Just a thought, but maybe that's why Nissan recommends L2 charging over L1...

 

[DaveinOlyWA]

Recommendatio is based on time to charge and nothing else

Just a thought, but maybe that's why Nissan recommends L2 charging over L1...

 

[garygid]

Problem:
Heater coolant gradually gets very hot while charging.

Normal:
Heater coolant stays at ambient temperature, no heating.

Variations:
L1 vs L2 makes no real difference.

Something is heating the Heater coolant, eventually too hot to touch.

 

[smkettner]

What happens when you pull the wire off the heating element? or pull the fuse if that is easier.

 

[derkraut]

Problem:
Heater coolant gradually gets very hot while charging.

Normal:
Heater coolant stays at ambient temperature, no heating.

Variations:
L1 vs L2 makes no real difference.

Something is heating the Heater coolant, eventually too hot to touch.

So....take it to your dealer. :!: