[jlsoaz]

Hi - I just can't seem to find the answer to this yet, in the FAQS:

I just got a 2013 Volt. I'm in Arizona and did have a 2012 Leaf that lost two bars, even though I did try to follow all the manufacturer recommendations.

So, when the Volt is in the garage, the temperature can vary outside from below freezing to above 110 degrees F. This is well above the 86 degrees I saw recommended for long-term storage. (My question here today is just about day-to-day typical garage sitting, not about long term storage, though I suppose it also applies to that).

I'm assuming even if the garage is shaded it can also get hot beyond the recommended temperature. So, if I leave the Volt plugged in, even when it is fully charged, will that in some way help protect the battery? Does the vehicle ever run A/C to keep the battery cool? If so, is this a big use of electricity in my garage during the summer months?

The vehicle has about 39.5k miles and shows 40 miles range, though noting I've only had it through one or two charge cycles.

 

[saltsman]

Unlike the early versions of the Leaf, the Volt has active thermal management of the battery pack. GM did a fabulous job on battery longevity with the Volt.

Therefore, you want to keep it plugged in as much as you can. It will keep the battery pack cool in the heat and also allows you to pre-condition the cabin before taking it out. If you have over half the battery, the Volt will cool the battery even on battery power.

For long-term storage, store it with half charge and enjoy the extended vacation.

 

[jlsoaz]

Unlike the early versions of the Leaf, the Volt has active thermal management of the battery pack. GM did a fabulous job on battery longevity with the Volt.

Therefore, you want to keep it plugged in as much as you can. It will keep the battery pack cool in the heat and also allows you to pre-condition the cabin before taking it out. If you have over half the battery, the Volt will cool the battery even on battery power.

For long-term storage, store it with half charge and enjoy the extended vacation.

Ok, thanks, I also see this thread from a long time ago, that I was just referred to a few moments ago:

http://gm-volt.com/forum/showthread.php?10267-Leaving-Volt-plugged-in

So, these points made a long time ago also seem to point to erring on the side of keeping it plugged in, at least during situations where the temperatures might be extreme. I'll leave it plugged in a bit more and read the manual a bit more, though we are going into a more temperate time of the year.

 

[freshcut]

Agreed. I try to keep mine plugged in when it's here at home. Not only do I get the benefit of nearly always having a full charge, but it also helps heat and cool the battery to maintain an ideal temperature. Although the TMS (Thermal Management System) uses electricity from the EVSE to maintain an ideal temperature, it doesn't seem to make a drastic impact on total monthly usage. Since the system uses liquid cooling, most of the time it's just a matter of running the pump to circulate the coolant through the battery cells and will heat/cool the water as needed. Combined with the excellent insulation of the entire battery package, it doesn't really require significantly more electricity than just plugging in to recharge. I know during the summer here in Central California I hear the system operate on occasion but it's mostly just the fan and pump operating. I rarely hear the a/c compressor engage, and assume the same is true when winter hits and the heat may be called on.

 

[TheBlueFlash]

Congrats on the MY2013 Volt purchase. One thing to be aware of is that you're coming up on the 5yr or 100k mile coolant system flush and fill. My 2013 was manufactured in October 2012, so mine was due this month. Yours may be too. If you don't have receipts to prove it was done by the previous owner and GM can't find a record of it being done in their system, assume it wasn't done. I wouldn't put this service off since the TMS gets quite a workout in your environment.

 

[TheBlueFlash]

If you have over half the battery, the Volt will cool the battery even on battery power.

I thought this was true as well, but I've read on here recently that in fact it does not engage the TMS while unplugged and powered down.

See: http://gm-volt.com/2013/05/03/volt-battery-thermal-management-system-in-the-hot-arizona-sun/

 

[freshcut]

I thought this was true as well, but I've read on here recently that in fact it does not engage the TMS while unplugged and powered down.

I've been under the impression that outside of being plugged in, regardless of the state of charge the TMS does not operate without wall power. It will however, in the case of power demands exceeding that of the EVSE (L1 in particular), it can use the battery to make up the difference for the demand. I just know that I'd rather pay a few extra cents in daily electricity cost to keep the battery in that happy range to avoid potentially costlier repairs later when the battery is no longer under warranty.

 

[Barry]

Don't overthink it. When you get home, you are going to plug in to charge the battery (and power thermal management). When you are ready to drive somewhere, you are going to unplug so you don't drag your house along with you. That's all you need to remember.

 

[tacman7]

Living in a hot climate changed my driving habits.

So if I'm doing a trip that will require burning some gasoline I go on hold a few miles after leaving the house.

If possible I run gas on the freeway and battery around in the city traffic but I try and keep half the batter charged or so.

The reason being when parking in the heat the car will cool off the battery if it has the juice to do it.

I try and calculate when to go back on battery on the way home to use up all the battery to get the best gas mileage so I have an empty battery when I get home and put it on the charger.

 

[flyingsherpa]

Agreed. I try to keep mine plugged in when it's here at home. Not only do I get the benefit of nearly always having a full charge, but it also helps heat and cool the battery to maintain an ideal temperature. Although the TMS (Thermal Management System) uses electricity from the EVSE to maintain an ideal temperature, it doesn't seem to make a drastic impact on total monthly usage.

Note that while the Volt can heat and cool the battery when plugged in, it doesn't do this nearly as often as people think... it's not like it maintains the pack at a perfect 72º all the time when plugged in. If it's 90 outside and you're done charging, it won't do a thing. If it's 20 degrees and you're done charging, it won't do a thing. It takes some extreme temperatures (and significant time at these temps) before these modes will kick in, that's why you're not seeing excessive energy consumption... it's probably not doing anything. It also takes quite some time for the battery to change temperature to ambient, so if you're charging in your 100º garage, it will cool it while charging, then it will take many hours (see link below) for the pack to get hot enough to where it might kick in the preservation mode, and by that time you'll probably be leaving for work anyway. Now yeah, if you're storing it in a 110º garage for a few days without driving or charging (but plugged in), I would expect it to kick in. But for a daily driver, even in AZ, you probably won't see it much if you're charging it every night (because it will cool while charging). FYI, you'll be able to hear it kick on.

To answer OP, yes... just leave it plugged in, no reason not to. It may not kick in outside of charging that often (depending on your driving / charging schedule) but it could, especially if you're not using it much. It will protect the battery as needed. I often don't plug in at home if I don't need a charge to get through my next day's commute, but if I lived in AZ I would, just for the protection.

Edit: Regarding it cooling itself when not plugged in, this article shows it not happening even in AZ on a hot day. There is speculation it would have kicked in if it got any hotter. But there are many factors here...

 

[Barry]

Living in a hot climate changed my driving habits.

So if I'm doing a trip that will require burning some gasoline I go on hold a few miles after leaving the house.

If possible I run gas on the freeway and battery around in the city traffic but I try and keep half the batter charged or so.

The reason being when parking in the heat the car will cool off the battery if it has the juice to do it.

I try and calculate when to go back on battery on the way home to use up all the battery to get the best gas mileage so I have an empty battery when I get home and put it on the charger.

This technique is probably not helpful, if the information in post #6 above is accurate (no thermal management with car off and unplugged). It would be better for the battery to drive it in normal mode, so it will discharge and you would park it empty. The battery is less sensitive to heat at lower states of charge.

 

[2VoltFamily]

Just plug it in when possible. From the 2013 manual:

Do not allow the
vehicle to remain in temperature
extremes for long periods without
being driven or plugged in. It is
recommended that the vehicle be
plugged in when temperatures
are below 0°C (32°F) and
above 32°C (90°F) to maximize
high voltage battery life.

 

[mpmoore1979]

In Phoenix in the summer time, my car will run the a/c to cool the batteries about every 2 hours or so for a few minutes. I also noticed that the thermal management will not run if the Time of Rate function is used and you are in the time zone of not charging.

 

[Kraven]

In Phoenix in the summer time, my car will run the a/c to cool the batteries about every 2 hours or so for a few minutes. I also noticed that the thermal management will not run if the Time of Rate function is used and you are in the time zone of not charging.

Thanks mpmoore, is this your observation of both Gen1 and Gen2 (regarding time of rate function) or only the Gen1?

 

[srmarti]

Yes. Keep it plugged in to assure battery temperature is maintained within recommended range, etc. Might consider unplugging it during severe thunderstorms.

 

[hellsop]

Thanks mpmoore, is this your observation of both Gen1 and Gen2 (regarding time of rate function) or only the Gen1?

Gen 1 at least. http://gm-volt.com/2013/05/03/volt-battery-thermal-management-system-in-the-hot-arizona-sun/

I doubt that Chevy would change much about this to Gen 2. It's not a "garage door button" inconvenience level change; it's likely to be having a significant impact on the longevity of the mostly heavily-warrantied portion of the car.

 

[Kraven]

Thanks hellsop, my post was about TMS NOT running if the heat experienced would trigger TMS, but if the time of day is not a time that the vehicle would charge (on peak hours, more likely when heat is being experienced). This seems to put the battery in harms way, not allowing TMS to operate, even if plugged in but during peak hours.

The article you linked to states that the battery can actually withstand very high ambient temperatures, 100 degrees for example, but still not trigger TMS because of the insulation of the battery. The battery would only get to 90 degrees or so, and TMS doesn't activate until the battery gets above 90 degrees.

So it seems unless you are experiencing 110 degrees or more in ambient temperature, you don't have to worry too much about the battery being harmed by high temps.

Another thought is, when unusually high temps are being experienced, is to remove time of day charging (by either the menu system or simply plugging the charge cord in, unplugging, and plugging back in to set charge to "immediate". This would take mpmoore's example/statement out of the equation and allow TMS to operate even during peak hours.

 

[jlsoaz]

Congrats on the MY2013 Volt purchase. One thing to be aware of is that you're coming up on the 5yr or 100k mile coolant system flush and fill. My 2013 was manufactured in October 2012, so mine was due this month. Yours may be too. If you don't have receipts to prove it was done by the previous owner and GM can't find a record of it being done in their system, assume it wasn't done. I wouldn't put this service off since the TMS gets quite a workout in your environment.

cool (pun acknowledged), thanks for the tip.

 

[jlsoaz]

Living in a hot climate changed my driving habits.

So if I'm doing a trip that will require burning some gasoline I go on hold a few miles after leaving the house.

If possible I run gas on the freeway and battery around in the city traffic but I try and keep half the batter charged or so.

The reason being when parking in the heat the car will cool off the battery if it has the juice to do it.

I try and calculate when to go back on battery on the way home to use up all the battery to get the best gas mileage so I have an empty battery when I get home and put it on the charger.

Ok, thanks.

 

[voganni]

Another benefit of leaving Volts plugged in (2013and up) is it will keep the 12v battery maintained at 13.0 volts, whether charging the big battery or not. Nice feature! Not sure how the car accomplishes this, but I've confirmed it with a voltmeter. I've observed Hal run his A/C occasionally during charging on hot days, and sometimes I'll hear the A/C compressor run whilst plugged in and not charging. Not too often though. Much more often I hear the circ pump and cooling fans.