In cold temps, ICE turns on at the begining of a trip when I have plenty EV. Why?

I know! wrap an electric blanket around the battery!

 

How about around the whole car!

 

Yeaaahhhh, no. Once you take the blanket off all the heat dissipates. The mass of the battery would hold heat better than the cabin of a glass surrounded car.

 

Absolutely right on all accounts, However the warmed air must get into and around the battery compartment. otherwise it is all to no avail. There must be airflow and spent air must exit.

The reverse of what has been attempted could theoretically happen. The procedure set up for warming up the battery works incredibly well and now the car is showing a red triangle. Normally the air flow thru the ducts is designed for battery cooling.

 

That's why wrapping the battery entirely in an electric blanket and leaving the electric blanket installed around the battery could work. Once you remove the power to the electric blanket (in my case, the 120 volt outlet next to my parking space) And drive the 11 or so miles in EV at speeds approaching summertime temps. the battery temperature would gradually go down to ambient temps. (you ask.....what about battery being charged? I charge it first, then connect electric blanket power over night)

You mean using the charge timer? Yeah...I tried that when the ambient temp was 40 degrees, I immediately drove down my street at 35 mph and ICE came on.

 

I'm always in ECO, didn't get the ICE turning on when I had your temperatures, but now we're down to forties Farenheit (5 - 10 C), if I don't get it to LO in the first ten seconds the ICE is on. For those of us with European models, CITY seems to be a better ICE suppressant than ECO, but even that will switch itself off if the heat setting is sufficiently above ambient.

 

About that theory using the charge timer to preheat the battery, since the battery capacity is 4 KW and only 85 % is charged (according to my Kill A Watt meter about 3 KW is used to charge the battery) The amount of watts/ BTU's left over is probably not enough to sufficiently warm the battery (IMHO)

 

I was considering putting both seat heaters on all night, a tightly closed car and at the same time a fan on low, probably need to have the car in ready, key left in car to accommodate fan on AND also to set timer for charging around 0400. Barring this, leave in ready, plugin and charge, if feasible with seat Warmers going. Probably both situations are not possible.

 

If you mean did the ICE ever come on during the trip...no, it didn't.

It was round trip...so dead even on the elevation.

Speed limits were 35 or 40 (posted) most places with 50 mph for one segment.


I suppose all of this demonstrates the advantage of having a relatively warm garage.

 

It is likely a overcharge condition would have to exist to warm up the battery ( in Winter )

A warm garage dood it. Until you have to brave the outside and then after two hours outside the car is very likely to use the ICE, with out your agreement.

 

As soon as you plug in, the car will shut off regardless of timer setting. But there has to be a way.

No, I meant were you using regenerative braking to increase the range e.g. long downhill but you answered the question of elevation. Thanks.

 

I suspected some sort of nefarious reaction.

 

It must be to keep the numb of brain matter from driving off when still plugged in.

 

ahhhh, the warm garage scenario

 

You mean aside from me, who you just quoted saying that...?

I've seen small 600 watt oil-filled electric radiators. That would be the appropriate size, I think.

 

how many BTU's will it take to warm the cabin/battery above ambient temperatures?
Watts to BTU conversion calculator

And how many BTU's are needed?

BTU Calculator

also remember there is very little insulation through glass which most of the cabin is comprised of.

Found a more accurate calculator
How much heat does that room need?

I entered 4 feet by 6 feet by 12 feet and got this:
3,478 BTU/Hour required to heat a 288 cubic foot room [4 high x 6 wide x 12 long] with 20 sq. feet of Doors, 40 sq. feet of Windows and 0 Fireplace.

So maybe a 1270 watt heater would cut the mustard.

4333.4198739 btu's/hr

 

Does all of this figure in -20 degrees f outside, 20 mph winds and heat loss and rate of that heat loss and how fast it can recover that heat loss? or hold a 45 degree temp. for the battery?

 

probably not. But I think, based on this thread 50 or above degree temp's for the battery is needed. That's why an electric blanket would be a better option for the battery. ( less square footage to heat and battery located in trunk area ( more insulation than the windows in cabin area)

 

But....The heat is needed IN the battery compartment, not in the cabin.

 

I have been thru this on a very small scale. By partially covering the metallic cover on top of the battery with a small elec pad ( 1 Ft square )It did raise the range by 1/10 of a mile, from 13.9 to 14. But that is way too little. As John said it has to be professionally done by the Manufactuer.