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Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Wed Jan 25, 2012 12:16 am
by Herm
Could someone try one of those magnetic oil pan heaters on the Leaf's battery pack before spring comes?.. I would like to see if it does bring up the battery temperature a noticeable amount.

Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Wed Jan 25, 2012 12:19 am
by TonyWilliams
Herm wrote:Could someone try one of those magnetic oil pan heaters on the Leaf's battery pack before spring comes?.. I would like to see if it does bring up the battery temperature a noticeable amount.
Except we don't want oil pan temperatures on our LEAF batteries !!!

Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Wed Jan 25, 2012 3:11 am
by Herm
How hot do you think those heaters will bring up 4 quarts of oil?.. about 130° F, compared to 600lbs of batteries.. and also keep an eye on it and see what it does in an hour or two, sheez!

Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Wed Jan 25, 2012 1:28 pm
by TonyWilliams
Herm wrote:How hot do you think those heaters will bring up 4 quarts of oil?.. about 130° F, compared to 600lbs of batteries.. and also keep an eye on it and see what it does in an hour or two, sheez!
So, your suggestion is to expose the thin metal case of the batteries to some temperature close to 130F (and up to 200F) ?

No thanks.

But you're right about 600 pounds of batteries perhaps only warming up to some number less than that.... after damaging the parts of the cells exposed to temperatures well in excess of design.

Oil pan heaters are the perfect combination for warming the battery.... we just need to keep the temps reasonable.

Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Thu Jan 26, 2012 7:44 am
by muus
TonyWilliams wrote:Oil pan heaters are the perfect combination for warming the battery.... we just need to keep the temps reasonable.
The biggest problem with an oil-pan heater is that it applies heat to a small area (couple square inches). What you need is a way to apply heat evenly to the whole surface of the battery box.

Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Thu Jan 26, 2012 8:33 am
by TonyWilliams
muus wrote:
TonyWilliams wrote:Oil pan heaters are the perfect combination for warming the battery.... we just need to keep the temps reasonable.
The biggest problem with an oil-pan heater is that it applies heat to a small area (couple square inches). What you need is a way to apply heat evenly to the whole surface of the battery box.
I guess that seemed obvious to me:

Yes, cover most of the metal bottom of the battery. That will require more than the size of a typical "oil pan". You can buy that stuff just about any size you want.

Item two, reduce heat output to 30-40C (80F-100F).

Three, don't put the heaters under electronic controls that we don't want to heat. I'd Use a big U pattern. I'm not worried about damage, just saving a couple bucks on heating pad material. I also probably wouldn't put the material on the bottom support beams.

Finally, run the appropriate size 120v through the motor compartment to the charging port, and label it "120v XXamp Aux Battery Heater".


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Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Thu Jan 26, 2012 6:17 pm
by DaveinOlyWA
ok i F'ing DID IT!!!

charge complete 6 pm; 98.5% SOC GID 276.
started trip 5:30 AM 97.8 SOC GID 274 temp 38º

lost BB 12 (battery bar) @ 90% GID 250 4.5 miles
BB11 @ 82.3 % & 233 and 41º
10 @ @77.2 & 217 and 41
9@ 70.1 & 197 and 43
8 @ 62.9 & 178 and 43
7 @ 58 & 163 and 43
6 @ 49.8 & 140 and 43
5 @ 43 & 121 and 43
4 @ 36.2 & 102 and 41º
3 @ 30.2 & 85 and 41
2 @ 21.3 & 60 and 75.5 Miles (all other temps stayed at 41)

LB @17.4 & 49 80.8
VLB @ 8.5 & 24 and 92.7
lost first power circle @ 98.8 miles
turtle @ 2.8 and 8 and 99.3

total trip ONE HUNDRED MILES PLUS!!

Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Thu Jan 26, 2012 6:19 pm
by DaveinOlyWA
ok, so we have some doubter??

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Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Thu Jan 26, 2012 7:09 pm
by edatoakrun
[quote="DaveinOlyWA"

total trip ONE HUNDRED MILES PLUS!![/quote]

Congratulations!

Is that the coldest 100 M yet?

Please post more details.

I'm assuming it wasn't all at freeway speed...?

Re: Wanted: Extreme Cold Range Data (earn free t-shirt!)

Posted: Thu Jan 26, 2012 7:19 pm
by DaveinOlyWA
nope, never touched freeway. it was 7 errands plus work commute. there was 14 miles from yesterday which was commute (11.8 miles) and dash to albertsons for junk food.

the rest of the miles were from today. it was the normal routine. only difference was i put off my usual tuesday stuff for today so a few more trips than normal but all streets and did circle a nearby neighborhood from 93.6 miles until 98.9 then headed home as soon as the power circles started to disappear. temps ran between 39 and 43 º. yesterday the weather was rainy, today beautiful and sunny which allowed me to use minimal defrost and did not get the extra drag from rolling on wet pavement.

i will say the SOC made it easy to be brave since i had never driven that far past VLB before. i ran it down to single digit GID and 2.5 % SOC!