rklisch
Posts: 10
Joined: Fri Dec 15, 2017 2:34 am

Battery Climate Control?

Tue Dec 19, 2017 1:34 am

The Bolt is equipped with a battery climate control system. Yet there seems to be so little information on this, and no vehicle instrumentation for this. Battery temperature has everything to do with it's health, longevity, and range. So it makes sense GM has designed this in, but as an owner I can't seem to learn more about this. For instance, while charging a car in a cold climate, do they warm the batteries? It seems they do not because my cold weather range is terrible. One would think if you are plugged in all night, then why not keep the batteries at 60 or 70 F? I would then expect a pretty full winter range. What am I missing here? Also, it would be nice if the instruments displayed battery temperature, the sensor is already there. It's just a tiny bit of software. Maybe that is just too technical for the average owner.

How is this battery climate system controlled? When is it actually used? And how does one know it is in use and working?

Thanks,

Roger K

GetOffYourGas
Posts: 956
Joined: Tue Oct 20, 2015 5:25 pm
Location: Syracuse, NY

Re: Battery Climate Control?

Tue Dec 19, 2017 12:41 pm

This has been an annoyance of mine since I got the car. The Leaf had zero thermal management, but displayed rough battery temperature (in "bars") prominently on the dash.

rklisch wrote:Also, it would be nice if the instruments displayed battery temperature, the sensor is already there. It's just a tiny bit of software. Maybe that is just too technical for the average owner.


I like to think of this in terms of an ICE car - most cars show you coolant temperature. The Bolt is equivalent to only having an idiot light go one when it's too late.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV (traded for Bolt)
2015 C-Max Energi (302A package)
2017 Bolt Premier

winterescape
Posts: 113
Joined: Sun Jun 25, 2017 1:35 pm

Re: Battery Climate Control?

Tue Dec 19, 2017 1:36 pm

You might desire to understand more about the TMS in the Bolt, as do I, and as do all of GMs competitors, I don't think they are going to tell us much more than what is displayed in the efficiency screen showing the % of energy consumption used for TMS. There have been a few threads where folks have empirically determined it turns on when plugged in and the pack temp is below freezing. Someone with a current monitor on the EVSE posted plots of the TMS energy consumption "blips" amplitude and period at a couple of temps.

IMHO, if GM turned the TMS on frequently and warmed the pack to 60 deg as you suggest, there would be several threads complaining about how much energy the Bolt wastes conditioning the pack compared to how "smart" Nissan was in not adding the cost or complexity to condition the pack

rklisch
Posts: 10
Joined: Fri Dec 15, 2017 2:34 am

Re: Battery Climate Control?

Tue Dec 19, 2017 1:55 pm

winterescape wrote:
IMHO, if GM turned the TMS on frequently and warmed the pack to 60 deg as you suggest, there would be several threads complaining about how much energy the Bolt wastes conditioning the pack compared to how "smart" Nissan was in not adding the cost or complexity to condition the pack


I read one post here where a Bolt owner heats his garage to 60F though the winter. I thought to myself, how crazy to buy a Bolt for the reasons of reducing emissions, then heat an entire garage all night. GM could give the option to heat or not heat the pack. The extra range the next day would be useful. Also, the Volt (I have under lease), causes the ICE to run in the winter for heat. No option to turn that off. GM ought to give us EV pioneers more options.

mwk
Posts: 18
Joined: Wed Oct 25, 2017 8:15 pm

Re: Battery Climate Control?

Tue Dec 26, 2017 10:50 pm

I am sorry if I'm "hijacking" this thread, but it seems fairly relevant to my question. I am a new Bolt owner (Nov 1 2017). I live near Boston. For now, I just have been charging my car using the included 120v cable and an all-weather outlet on the side of my house near the driveway. I only have a 10-mile round trip commute, so I get more than enough range by plugging it in overnight. There's also an EVSE at my office I can use if I want.

Anyway, the forecast for this week is bitter, bitter cold with temps below zero a few nights. I'm also off work for the Holiday week and I'm not really going out very much, so the car is sitting in my driveway, un covered. Should I keep it plugged in to the 120v outlet when it's not in use, during this extreme cold snap? I'm worried about the batteries, obviously. Will it do harm to the EVSE cable itself if I leave it plugged in continuously?

Thanks.

BikingManiac
Posts: 8
Joined: Sun Apr 02, 2017 12:34 pm

Re: Battery Climate Control?

Wed Dec 27, 2017 1:28 am

Yes, leave your Bolt plugged in. Here in Wisconsin when it is below zero the car draws about 4 KWH in 24 hours.

LeftieBiker
Posts: 753
Joined: Tue Jan 10, 2017 7:13 am

Re: Battery Climate Control?

Wed Dec 27, 2017 2:10 am

Also, the Volt (I have under lease), causes the ICE to run in the winter for heat.


IIRC there is a menu option to select two temps at which the engine will start. The lower one is 15F. You might want to make sure you have that selected. At least the Volt has a cabin heater! Our Prius PHEV has no electric heater, so you have to run the engine for heat at any temperature...

Williams60
Posts: 7
Joined: Tue May 02, 2017 1:32 am

Re: Battery Climate Control?

Sun Jan 07, 2018 7:50 pm

As its been below -15 Celsius here for the last six weeks or so now (that's the daytime high, average nightly temp is below -25 Celsius), I can confirm the battery conditioning only kicks in when the vehicle is plugged in, or when the vehicle is running. The only advantage to leaving it plugged in when standing, is that the full regen takes some time to achieve if it hasn't been plugged in overnight. To quantify "some time", it depends on the temperature, but below -20C it takes around 5 to 8 minutes before the regen notification 'bar' starts creeping down the 'available regen' gauge to the right of the speedo, in a similar fashion to when you fully recharge the battery (as opposed to using hilltop reserve, which is all I usually use, less a charge to full capacity around once a month just for shits and giggles and to see what the predicted range at full charge is at this temperature, just in case I need its full range at some time). Worst range prediction (at full charge) that I've seen so far was 214km, after leaving it outside overnight below -28C (-18F) with a min (max?!!) overnight temp over of -32C. That battery conditioning rarely gets above a few percent of the battery usage, as the climate and propulsion draw far eclipses it, other than for the first 10-15 minutes of use, or if you use the pre-conditioning function, but it soon drops down as a percentage on the 'energy use' information graph once the vehicle starts moving.

You can hear the battery conditioning in operation when you plug the vehicle in to charge, if its' been standing for a while in the cold; you can hear the coolant expanding into the overflow bottle as the battery charging kicks in.

The power output is also reduced (limited to 60kW initially) once you're down below -20C. This increases pretty rapidly as the coolant circuits warm up and is not really an issue; I had to push the car harder than I should have done in those conditions to find what it was limited to, as you can't/shouldn't really try to accelerate that hard when it's -28C in deep snow.....lol!

LeftieBiker
Posts: 753
Joined: Tue Jan 10, 2017 7:13 am

Re: Battery Climate Control?

Sun Jan 07, 2018 9:42 pm

As its been below -15 Celsius here for the last six weeks or so now (that's the daytime high, average nightly temp is below -25 Celsius), I can confirm the battery conditioning only kicks in when the vehicle is plugged in, or when the vehicle is running.


Are you driving it daily? If so you may be keeping the pack warm enough to avoid the need for it to activate conditioning to protect the battery...at any rate, it seems clear that the system is at the least much more willing to come on when the car is plugged in.

IMAdolt
Posts: 103
Joined: Mon Jan 09, 2017 7:13 pm

Re: Battery Climate Control?

Mon Jan 08, 2018 11:01 pm

LeftieBiker wrote:
As its been below -15 Celsius here for the last six weeks or so now (that's the daytime high, average nightly temp is below -25 Celsius), I can confirm the battery conditioning only kicks in when the vehicle is plugged in, or when the vehicle is running.


Are you driving it daily? If so you may be keeping the pack warm enough to avoid the need for it to activate conditioning to protect the battery...at any rate, it seems clear that the system is at the least much more willing to come on when the car is plugged in.


I was under the impression the TMS will kick in weather or not it's plugged in running or not running till about 30% SoC? Seems silly to allow for battery damage in extreme weather to save a few watts of power for driving.

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