Winter EV operation

Looking at online parts catalogs, both Clarity EV and PHEV appear to have same heater (heat pump). This is good, and explains why the Clarity heater is so much better than my Volt in the 10 to 50 F range, and seems to use less power. Surprised they don't advertise this.

 

All EV's should have direct heating windshields; like the VW e-Golf. These would save a lot of energy, and hardly affect the range at all.

All EV's should have all the seats heated, and the steering wheel. The Bolt EV has the best steering wheel heater, and the e-Golf has the best front heated seats, that I have driven. (The Bolt EV's front seat heaters are wimpy ...)

Heat pumps should be standard, and they should (partly) work by pulling heat from the motor and the electronics. Heat pumps lose their ability to pull heat from the air, as the temperature drops - as air temp drops into the teens (F) and single numbers - then they all will need resistance heaters.

We can hope for better cabin insulation - efficiency always helps.

 

Viking79, could you post the link to the online parts catalogue for those of us too lazy to search for it? Thanks

 

Main Parts Store:
http://estore.honda.com/honda/customer-home.asp

Nothing in the Accessories for the Clarity so far but other parts here:

http://estore.honda.com/honda/parts/select-your-honda.asp?year=2018&dl=#2

George

 

No problem, I have never ordered from this place, just for parts reference.
https://www.hondapartsnow.com/

Heat pump looking unit:
https://www.hondapartsnow.com/parts-list/2018-honda-clarity-plug-in-hybrid-4dr-trng-clarity-phev-ka-cvt/heater-unit.html
https://www.hondapartsnow.com/parts-list/2017-honda-clarity-electric-4dr-trng-clarity-bev-ka-1at/heater-unit.html

However, the PHEV also shows this heater:
https://www.hondapartsnow.com/parts-list/2018-honda-clarity-plug-in-hybrid-4dr-trng-clarity-phev-ka-cvt/electronic-coolant-heater.html
Which could be a resistance heater for heating coolant.

And the BEV has a couple different units under the heater section. Like Exchanger Comp Inner, and Heater Core High Voltage PTC (which actually looks like a heater in itself, it is possible the BEV adds a resistance heater since it doesn't also have the engine at very low temps).

Maybe I take back that it has a heat pump. I really don't know at this point, any HVAC experts want to chime in? I am confused why a non-heat pump would have an evaporator, but maybe that is really for the AC?

 

I take it back, it looks like PHEV has a resistance heater and not a heat pump. I say that because of this:

The coolant heater appears to pump coolant straight to the heater core (part 4, see those coolant pipes going off?):
https://www.hondapartsnow.com/parts-list/2018-honda-clarity-plug-in-hybrid-4dr-trng-clarity-phev-ka-cvt/heater-unit.html

One of those coolant lines goes straight to this thing, that appears to be a resistance coolant heater (see that B17-20 line shows up on both diagrams?):
https://www.hondapartsnow.com/parts-list/2018-honda-clarity-plug-in-hybrid-4dr-trng-clarity-phev-ka-cvt/electronic-coolant-heater.html

The EV version shows the evaporator connecting to some other heat exchanger that is not in the PHEV version, parts 16 and 12:
https://www.hondapartsnow.com/parts-list/2017-honda-clarity-electric-4dr-trng-clarity-bev-ka-1at/heater-unit.html

My guess it is just a very rapid heater (probably heats the coolant immediately before sending it to the heat exchanger in the car, like on demand water heater.

 

Thanks to K8QM, Viking79 and others for helping us all to peer behind the curtain on this. I think we’re doing the same thing the Volt community has been doing for years in that we are accumulating and sharing knowledge until we get this figured out. Too bad Honda and GM won’t put out a tech manual for us.

 

Dear prestoOne, don’t know the source of that quote but it seems to say the battery and inverter are all on the same coolant loop. If you look in the manual and look under the hood, there are three separate coolant tanks.

On page 482 of the manual it points out locations and describes them as:
1. Inverter coolant expansion tank
2. High voltage battery system coolant expansion tank
3. Engine coolant reserve tank

Manual goes on to show checking of levels and leaks in each. Where did you find the quote that says the first two are all one system? Or am I just reading the manual wrong?

 

No prob. But where is the quote from?
It would help us understand the system better.

 

I heard resistance as well, and it uses around 6kw to use the heater where my Leaf, which definitely has a heat pump, uses around 3kw. But the Clarity certainly does start heating fast.

 

The other interesting thing is the parts in those diagrams, the EV version has a very different resistance heater in addition to its heat pump, it isn't a coolant based unit, but instead heats the air directly (looking at the picture anyway).

It looks like that quote was from Car and Driver, so they probably took it from some promotional material from Honda. It appears it has 3 distinct loops, not one. So the quote is maybe partly correct.

 

Most BEVs have both a resistance heater and a heat pump, as heat pumps are only useful above 0F or maybe even higher, depending on design. Leaf has both.

Heat pumps can be up to 400% electrically efficient or so at temps right around freezing, they take energy in the form of heat from the atmosphere. Once it gets too cold they are no longer able to do that, so have to rely on resistance heating.

 

Lots of problems with that Car and Driver article. Go to the end and read the comments on it.

 

Chiming in as another upstate NY winter driver. Our Clarity, plugged into 110 will automatically preheat every AM, but it does automatically disconnect from the AC when it does this. I get a text message every morning saying the car has stopped charging and is now preheating. It works well but is dependent on you leaving the heat on in the car when you turn it off at night. In other words, if you don’t have the heat on, it does not know what to preheat to so it does nothing.
As far as battery impact, the electric heat is amazingly fast and efficient. My wife loves it over any of our ICE powered vehicles. That said, seat heaters really seem to be a battery suck. I feel they can take 10-15 miles off the EV range if left on. I tend to not use them or only use the to initially warm the seats.


Sent from my iPhone using Inside EVs

 

After being overwhelmingly unimpressed with the pre-conditioning through the sub-zero winter temps, I installed my Level 2 charger and have the pre-conditoining start at 7 AM. Nowadays, the car is fantastically toasty warm when I get in at about 7:30. It works great with the Level 2 charging unit I have at home. Still not sure if it works well in sub-zero temps when not connected to a charger.

 

It will work, but your EV range will take a huge nosedive. That resistance heater absolutely sucks electrons out of our battery like there’s no tomorrow!