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Re: Hot Garage

Mon Jul 31, 2017 12:02 am

devbolt wrote:The car will actively cool the battery pack during the day while plugged in whether or not it is charging.

If you are on a TOU plan, you should be charging at night anyways. You can program the car to only charge during off-peak times and still leave it plugged in during the day...

Not on TOU plan, no benefit to me.

Have done immediate mid day as well as delayed late night charging but will just schedule charge to be completed by 7am, when temps are lower, from now on.
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Re: Hot Garage

Tue Aug 01, 2017 10:19 am

So I finally physically confirmed that the AC with freon does cool the battery while on DCFC. I don't know why I didn't think to do this sooner.

I opened the hood during DCFC and put my hands on the freon pipes and they were icy cold. Then I put my hand on one of the control boxes and it was damn hot! Then I put my hand on the liquid degas vessel for the electonics cooling loop, and the liquid was about 110 degrees.

This was while DCFC at 46 kw on a 63 degree outside evening.

Beware that DCFC'ing in Las Vegas on a 116 degree day is probably not a great idea. Expect the car to dial down the power to 24 kw or 16 kw to manage heat load. Still, faster than charging at home, but expect your charge-up to take longer than normal.

Oh... the car DOES NOT register "battery conditioning" while attached to grid power. It must only record battery conditioning while driving.

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Re: Hot Garage

Sun Sep 03, 2017 10:20 pm

It's 110. I gather from the discussion herein that to enable for battery cooling (conditioning), my Bolt needs to be plugged in and set to "immediate mode." I further gather that I don't want to charge it to full for two reasons: !) I gather better battery durability if not kept full (especially on a hot day), and 2) I don't want to demand power as it's a record-breaking hot day throughout the State and total power consumption might break the daily demand record set in 2006.

However, the car's battery is not full, and if I plug it in and charge it, I will be maintaining my battery but drawing power on a day best not to.

So, I have it plugged in a charging at 8 amps (not 12). I've turned on Hilltop Reserve. What else can I do?

Maybe my post is just a request that GM give the car a third option for charging beside 12 and 8 amps: Battery conditioning only.

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Re: Hot Garage

Mon Sep 04, 2017 5:02 am

Your car should keep its pack cool if it has more than 30% charge even if unplugged. I'd let it cool the pack from the pack's power, and recharge off-peak.

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Re: Hot Garage

Thu Sep 07, 2017 3:40 am

I learned more about battery cooling and being plugged in last night. I drove home on a 90+ degree day, and forgot to plug it in. I had fully charged it at a public charging station, and then drove 3 miles. I have "Hill-top Reserve" activated at home, but not elsewhere. After about 30 minutes being home, I realized I had not plugged the car in. So I did. Within moments, I heard whirring sounds. I popped the hood, and the coolant lines were cold.

And then this night, I had driven the car less than a mile, but I left the car out of the garage while I was working in the garage. When I put the car into the garage and plugged it in, again the battery conditioning AC turned on. It was about 80 degrees when I plugged it in, and the maximum temperature today was 91. The EVSE was plugged into a Kill-a-Watt meter, it the consumption varied from 250 to 800 Watts.

My point is that the car plugged in does more to protect the battery in a hot garage than just the battery alone.

I would like for Chevy to offer the option, when a car is plugged in, to power the battery cooling system, without charging the battery.

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Re: Hot Garage

Tue Sep 12, 2017 10:41 pm

There have been several different observations and suggestions on the discussion board about dealing with battery conditioning when the car is sitting at your house in hot weather. This last one by plj leaves me confused. As described in that post, the battery conditioning came on when the car was plugged in; but when the battery wasn't plugged in, with the same temperature and with the SOC over 30%, the conditioning didn't activate. It wasn't clear to me from the post if the car was actively charging but I'm thinking it was. Some posts have said that if the SOC was over 30%, the conditioning would come on even when the car wasn't plugged in. This seems contrary to plj's experience. Some have said the conditioning would occur in this circumstance but at a lower level. True?

I will soon be on TOU so would like to charge only at night but have the conditioning available in the day time. I also subscribe to the idea of reducing the number of charging cycles by recharging only when I get down to around 20-30 percent SOC and using Hill Top Reserve to limit the top end. So I'm very interested in knowing for sure if conditioning will occur if the car is unplugged but over 30% - the status of my car most of the time. I take plj's post to mean it might not.

A clever post by SparkE - viewtopic.php?f=21&t=6754&p=22229&hilit=vacation+storage+plan#p22229 - suggests a method for keeping the car plugged in but with only a minor charge occuring, by setting up the car's programming to only charge for 15 minutes a day using 110. While a bother to switch the plugging schedule and the cables back and forth, this would work for my charging program if I knew for certain that plugged in but not charging was sufficient to cause conditioning to occur. But I'd prefer to keep the car unplugged when I don't need a charge, if I can rely on the conditioning to occur with the charge over 30%.

Sorry for the lengthy post. Any clarification is appreciated.

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Re: Hot Garage

Tue Sep 12, 2017 11:21 pm

I would not assume (unless someone has tested this) that the car TMS will function when plugged into 110 V. My Focus Electric did not; it cooled only when plugged into 220 V. Bolt may or may not, I don't know.

I don't know where it was determined that 30% was the threshold for battery thermal protection happening even when not plugged in.

I wouldn't worry too much about battery temperature when the car is neither running nor charging providing the SOC is moderate. If your garage gets very hot, could you provide some ventilation? One of those wind turbines, perhaps, that are seen on warehouses?

How about doing a remote start on the car for 15 minutes during the heat of the day. I'm pretty sure that would cause the TMS to kick in if the battery were too warm.
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Re: Hot Garage

Tue Sep 12, 2017 11:26 pm

michael wrote:I would not assume (unless someone has tested this) that the car TMS will function when plugged into 110 V. My Focus Electric did not; it cooled only when plugged into 220 V. Bolt may or may not, I don't know.

It's also possible that the temperature thresholds for battery conditioning are relaxed when the car is on it's own power. It may be, for example (and these are totally hypothetical, made-up figures on my part) that battery conditioning will come on at 90F if the car is plugged compared to 100F or 110F when it's not.

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Re: Hot Garage

Wed Sep 13, 2017 4:18 am

To answer Airbesar, yes, the battery was charging, in "immediate mode," at 110 Volts, 8 amps. I suppose that's the crux of my question: does battery conditioning occurs only when charging or driving.

I concur with the observation that some -- but less -- battery conditioning appears to occur when the car is not plugged in and charging. I suspect the car I bought sat for in a hot lot though June and part of July (at least). The car's "lifetime efficiency," reported by the MyChevrolet App. is 3.0 mi/kWh, whereas since last full charge, efficiency has been 4.6 mi/kWh. That lifetime efficiency has been slowly climbing as I drive more. I suspect that those kWh were spent conditioning the battery as the car sat.

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Re: Hot Garage

Thu Sep 21, 2017 12:15 pm

From an enginneering standpoint, cooling while NOT plugged in makes little to no sense. I really, really doubt this would occur. I'm 99.9% sure the car does not cool unless plugged in.

Here's why. It could do more harm than good.
Besides being a case of trying to lift yourself by your own bootstraps (using battery power actually warms the battery) think of the practical sense.

I live 60 miles from a major airport.
I want to take a 2 week long trip and leave my Bolt parked in the outdoor economy lot. How terrible would it be to return to a Bolt with only 30% in the battery, or worse?!?!

Self-discharging at 800 watts (or close) while unoccupied and unattended for unknown periods of time sounds like a BAD idea, no matter how you look at it.

I have been in some 100+ degrees places with my Bolt EV. I have never witnessed it cool while unplugged.

Absence of proof is not proof of absence, but it sure points in the direction of a PLUG-IN REQUIRED for battery conditioning.


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