Texas Summer about to start - Temp Management System Questn

[jloucks]

Summer is about to hit Texas. I read every thread I could and wanted to verify...

The battery temperature management system will cool batteries when NOT plugged in.

True or False?

...because I cannot plug in at work and don't want to toast (literally) my car battery.

 

[dmen]

It will NOT cool the battery while parked but not plugged in.
Your options are:
-Plug in
-Park in shade or even better in a garage
-some folks have suggested remote starting your vehicle a few times during a hot day with your mfm app. Set cabin to off on your driver's display settings so you don't waste energy cooling the cabin (unless range isnt an issue I guess).

I believe it's less bad for the battery to just be hot, than it is for the battery to move energy while hot (both charging and discharging). So I'm not positive that remote starting periodically would really make a difference in battery life. If your car is at 110F midday but you don't leave until 7pm when car is shaded and it's 80 out, I think it will be fine. Remote starting before you leave for the day, especially if it's still hot, may be more worthwhile.

It seems like Ford really limited the car in some ways to maximize battery life- can't access more of the 23 kWh, no fast charging- and included liquid battery cooling, so I don't think they would have set the TMS to not cool when unplugged if it was a significant harm. But it only gets over 100 a few days a year here so I have had the luxury of not worrying about heat too much.

 

[v_traveller]

Yeah, unfortunately the thermal management system doesn't turn by itself on when unplugged.

I just wrote something up about dealing with this yesterday...thanks to the recent heat wave here in California, I got a warning message on the dash to plug in the vehicle when not in use:

http://ev-vin.blogspot.com/2014/05/the-heat-is-on.html

Also here's a previous thread on this subject that might help:

http://www.myfocuselectric.com/forum/viewtopic.php?f=14&t=1206&hilit=+remote+start

The idea behind remote starting is to run the thermal management system briefly to prevent the battery from reaching an elevated temperature that would have an adverse effect on battery longevity.

If you're not getting warning messages on the dash or via MFM email notification, my take is that you don't have to worry about toasting your battery. If you are, then remote starting as a response to the email notification, or better yet an hour or so prior to when you think you will get a notification, should keep the battery sufficiently cool.

 

[michael]

I've learned some things about the TMS that may be helpful.

Most importantly, it doesn't seem to start cooling until the battery temperature reaches somewhere between 96 and 98 F, so if the battery is below that, it simply doesn't make any difference. You are better off in the shade, not plugged in, than in the hot sun even if plugged in. This is bad news to those who believe (as I do) that the battery should ideally stay as close as practical to 70 F. The vaunted Ford TMS doesn't seem to work this way.

Secondly, I"ve found the battery temperature changes quite slowly when not in use. Apparently it's well insulated and/or of great thermal mass.

Third, it heats up a lot from the cabin being hot. I bought a reflective car cap (covers only the top area of the car) which brought the daytime temperature down, and the battery stayed much cooler as well.

And finally, you CAN run the TMS even when not plugged in. Simply walk away from the car with the car still "on", lock it with your remote, and go about your business. As far as the car is concerned, it thinks it's at a stop light, still running. While, as I said above, the TMS doesn't start working when off and plugged in until the battery gets to 96-98 F, I can't yet say whether it is more agressive (i.e., maintains lower temperature) when the car is running but not plugged in. I try to report on this .


One last thing, and I know this will generate argument, but if it's hot, don't charge your battery until you need to....practice "just in time" charging. This will reduce the amount of time spent at high temp and high charge, and this is a key battery killer.

 

[WattsUp]

And finally, you CAN run the TMS even when not plugged in. Simply walk away from the car with the car still "on", lock it with your remote, and go about your business. As far as the car is concerned, it thinks it's at a stop light, still running.

True, but the dash and MFT screens will stay lit up, which could attract unwanted attention. So, pick your poison.

 

[michael]

I don't think that's an issue. The car is locked. And especially if you are at work...in many cases the parking lots are relatively secure. I don't hesitate to leave my windows down a little at work although I wouldn't do so in a public place.

 

[jloucks]

Thanks for all the information FFE brain trust. I'll probably work out a system where I run the car while locked and leave the windows open and a shade inside.

I did read the other detailed thread on the percent of charge affecting the severity of effect of heat. By the time I get to work I have 'spent' at least 30% of charge, so I am not heating it at full charge. Not 1/3 charge like was recommended, but definitely not above 66%.

Thanks!

 

[WattsUp]

I don't think that's an issue. The car is locked. And especially if you are at work...in many cases the parking lots are relatively secure. I don't hesitate to leave my windows down a little at work although I wouldn't do so in a public place.

In a semi-private garage, like at work, maybe not an issue. In a public garage, the last thing I want to do is attract attention to my car. So, I'd personally never do this under those circumstances.

I also don't want anyone "helping" me either, thinking I've left my car turned on (which, in this case, would be true), contacting garage personnel, police, etc. who might come to investigate.

 

[jloucks]

I don't think that's an issue. The car is locked. And especially if you are at work...in many cases the parking lots are relatively secure. I don't hesitate to leave my windows down a little at work although I wouldn't do so in a public place.

In a semi-private garage, like at work, maybe not an issue. In a public garage, the last thing I want to do is attract attention to my car. So, I'd personally never do this under those circumstances.

I also don't want anyone "helping" me either, thinking I've left my car turned on (which, in this case, would be true), contacting garage personnel, police, etc. who might come to investigate.

That is a good point I hadn't thought about. Where I work there are very few thieves, but lots of helper fairies around. They would 'help' me out by turning off my car given an unlocked door. And if the door is locked I can hear the page every hour.. 'Would the owner of white ford golf cart please come to the reception desk, your cart is running, possibly.'