121gigawatts
Posts: 50
Joined: Sun Jan 06, 2019 5:37 pm

TMS and Cold Weather

Sun Jan 27, 2019 9:24 am

The TMS only keeps the battery warm while plugged in or while the car is running, correct? Its going to be -15 for the daily high on Wednesday, and -5 the rest of the week. If I have to park around town for a couple hours I have a couple questions.

1. How long do you think it takes for the battery (which is pretty well insulated in the trunk) to drop to an unhealthy temperature in say 0 degree weather? I know its hard to estimate, but since the battery is not spread out on the bottom of the car it should take a while.

2. If you precondition the car, how long would it take to warm up the battery to a healthy level if you dont have access to an EVSE while out and about? If afraid of leaving the car for 2-3 hours and harming the battery during regen.


Thanks!

triangles
Posts: 1056
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: TMS and Cold Weather

Mon Jan 28, 2019 5:16 am

Correct TMS only works while plugged in or car is on. I don't know for sure but some say it has to be L2 and that TMS doesn't work with L1. Honestly I wouldn't worry about it. The battery weighs ~700lbs That's not going to cool off or heat up very quickly. The high around here for Wednesday is -5F and the low is -16F. I'm gonna have to remember to grab my laptop and read some battery temps this week.
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

triangles
Posts: 1056
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: TMS and Cold Weather

Tue Jan 29, 2019 9:02 am

Preliminary battery temp readings. I finally found my ODBII dongle. It looks like with Forscan there is no battery temp sensor, I only found the battery coolant loop sensor which is what I'll refer to as battery temp. I also didn't see any parameter that indicates whether any of the 3 battery heaters were active. If anyone more experienced with Forscan sees that I missed something please let me know.

Battery coolant was at 60F yesterday after charging up to 99% with 34F ambient temp. This morning it had dropped down to 14F ambient and the battery plugged in overnight was at 30F. My 20 minute commute the battery warmed up to 46F. The temp is forecast to drop down to 10 when I leave work. We'll see what the battery temp is after sitting for 9h with the ambient temp dropping from 14 to 10F.
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

121gigawatts
Posts: 50
Joined: Sun Jan 06, 2019 5:37 pm

Re: TMS and Cold Weather

Tue Jan 29, 2019 10:20 am

Interesting data, thanks!

thanhdaica1985
Posts: 49
Joined: Mon Oct 22, 2018 2:23 pm

Re: TMS and Cold Weather

Tue Jan 29, 2019 10:42 am

The value for battery is H_BATT_TEMP i think. The coolant temperature is usually warmer than the temperature of the battery when it's cold.

triangles
Posts: 1056
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: TMS and Cold Weather

Wed Jan 30, 2019 5:40 am

Thanks thanhdaica1985. I could have sworn I looked thru all the parameters and only temps available were outside and the 3 coolant loops. I'll check it again. FYI after sitting over night at 10F dropping to -8F My battery coolant temp was 24F. IIRC it started at 40F
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

triangles
Posts: 1056
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: TMS and Cold Weather

Fri Feb 01, 2019 5:52 am

So now that I know how to find the relevant parameters to monitor we can finally get some useful data. After sitting plugged in for 30+ hours in sub zero F temps, the battery was at 34F. and the battery coolant was significantly below freezing. Shortly after turning the car on the battery coolant jumped up into the 40's F. So just watching the coolant temp as I had been doesn't really mean much. I'll get more data points and post back later next week but initially it looks like the TMS tries to keep the battery above freezing when plugged in.
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

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