My Volt is roasting my Leaf

[LTLFTcomposite]

We all know the Volt has TMS, aka cooling for the battery, but of course cooling really just means moving heat from one place to another, creating more heat in the process. I've noticed the Volt charging in the garage (which would be on the warm side anyway) is sitting there with its battery cooler running, making the garage downright hot. Our current MO is to charge the Volt, then before going to bed switch the plug to the Leaf. It's gotten so warm out there I'm concerned about what it's doing to the Leaf, and have taken to opening the garage door for a while. I may need to add some kind of exhaust fan to cool the garage.

 

[adric22]

We have noticed the exact same issue. I've been leaving the garage door cracked. So it gets about 6 inches on the bottom and 6 inches on the top that allows some air to circulate. I'm not sure how much it helps, but it is bound to be better than letting it sit in there and cook. We may be trading the Leaf in for a second Volt at some point in the future and I've wondered how hot the garage might end up then.

 

[Weatherman]

That was exactly what I noticed when I drove my new Volt home for the first time on Saturday. Plug it in and let it charge and it dumps an incredible amount of heat out into the air. Really makes you appreciate what the LEAF battery was going through when it charged. Basically, it was cooking the battery.

I don't have enough room in my garage for two cars, so the LEAF stays outside, but the garage door stays open until the Volt can complete its heat dump. Once it's done, air temps in the garage stay pretty constant in the mid 80s, even with the door closed.

 

[LTLFTcomposite]

That was exactly what I noticed when I drove my new Volt home for the first time on Saturday.

Congrats on the Volt! I take it you found a red one. What dealer?

 

[Weatherman]

Congrats on the Volt! I take it you found a red one. What dealer?

AutoNation, Pembroke Pines. They got me the one from the Ft. Lauderdale AutoNation dealer.

I was in absolutely no mood to haggle, so I walked into the dealership and simply asked if they were willing to match GM's national lease offer along with the $1,000 lease conquest rebate. With hardly a comment to the contrary, they did and they threw in the Crystal Red color and the Enhanced Safety Pack 1 (backup camera and proximity alerts) for no extra cost.

 

[Deleted member 9549]

I wonder how much of that heat is from the ICE. Amazed how cool the Leaf and garage is after leasing a Leaf.

 

[Weatherman]

In my case, I'm pretty confident there was no contribution from the ICE. I've been driving the car at relatively low speeds and short distances since I got it. I don't think the ICE has kicked in once.

When you consider the heat capacity of the battery and the heat capacity of the surrounding air, it's no surprise that lowering the battery temperature from near 90 down into the lower 70s will warm the surrounding air, significantly.

 

[TomT]

The Tesla S also pumps out a fair amount of heat when charging... I'd much rather have it in my garage than in my battery though!

 

[Stanton]

Guess there's always "unintended consequences" to every design. I can't help but think about all the EXTRA energy the TMS draws/uses just to do it's job.

 

[Nubo]

I'd tend to think there'd be more heat energy attributable to the Volt's ICE engine, radiator, transmission, and exhaust systems cooling down, than from rejected heat during battery charging.

 

[CarZin]

I can't help but think about all the EXTRA energy the TMS draws/uses just to do it's job.

About 1.5-2 kWhs for a full charge is my estimation. Takes just under 13 kWh to charge 10 kWh usable.

 

[Weatherman]

Guess there's always "unintended consequences" to every design. I can't help but think about all the EXTRA energy the TMS draws/uses just to do it's job.

Just one of the joys of living in a hot-summer climate. Until I got solar panels, I used to cringe at the nearly $300/month electric bills I got just to keep my home A/C running. Of course, going without A/C is not an option in South Florida, and based on my experience with the LEAF, I'd say going without a TMS on a car's battery is not an option in South Florida, either.

 

[Boomer23]

"Fascinating", as Spock would say. I hadn't thought of this being an issue, but it's obvious if you think about it.

My flat roofed, uninsulated garage here in So Cal gets a good 10 degrees warmer than outside ambient temps. I have an ancient, noisy exhaust fan in the garage ceiling that the first owner of our house installed in the 70s, but it does an amazing job of cutting the garage temps in a hurry. I recommend researching exhaust fans.

 

[LTLFTcomposite]

The hotter the garage gets, the harder the TMS works, creating more heat of its own in the process. It's a vicious cycle. Never noticed it with the Leaf, like you said, it could be it's just cooking the battery, on the other hand the Leaf doesn't have a TMS compounding the problem. May have to leave the Volt out on the driveway to charge.

I wonder if a bathroom vent fan would be enough to help or if I need something with more oomph.

 

[Volusiano]

I'd tend to think there'd be more heat energy attributable to the Volt's ICE engine, radiator, transmission, and exhaust systems cooling down, than from rejected heat during battery charging.

Not if the Volt is driven far enough for the ICE to kick in.

 

[Weatherman]

It's funny that us LEAF owners are so sensitive to this.

Just about any other car owner would say, "Of course the car heats up the garage when I get home. What's the big deal?"

 

[Volusiano]

It's funny that us LEAF owners are so sensitive to this.

Just about any other car owner would say, "Of course the car heats up the garage when I get home. What's the big deal?"

So true. For a LEAF owner who also has an ICE car in the same garage and actively in use, the ICE car probably puts out just as much if not more heat from their hot ICE after a trip back from the commute than the Volt does.

 

[LTLFTcomposite]

But the ICE starts cooling down, the Volt keeps on cranking out the heat.

The Volt in the garage reminds me of when I cheaped out and built in one of those dorm fridges instead of paying the big bucks for a real built in that exhausts the heat out the front. The heat has no place to go, so it keeps generating more and more heat trying to keep cool.

 

[LEAFfan]

But the ICE starts cooling down, the Volt keeps on cranking out the heat.

That's a great point! My wife's ICE raises the garage temp one or two degrees when she comes home at night, but it doesn't stay there for long.

 

[Volusiano]

The notion of the Volt keep generating more and more heat implies that the garage is a closed system and there's no place for heat to escape such that the Volt constantly runs all the time and things get progressively worse, which is not true. The Volt right now is the only car in my garage and it does stop cooling after it's done its job. My garage does dissipate the heat without having to crack open the door a little bit, so it is not a closed system. I don't see my Volt TMS running constantly all the times and keeping on cranking out the heat.

This is consistent with the comment that LEAFfan made above, that even the heat from his wife's ICE doesn't stay there for long -> it's not a closed system and it does dissipate heat.

Now if you have a 1 car garage only that is very airtight, then the effect may be more dramatic. But for a normal 2 to 3 car garage, the volume is large enough to help dissipate the heat fast enough. Remember that the Volt battery is also very well insulated. The heat should dissipate through the garage walls and ceiling faster than it should seep back into the well insulated Volt battery.