How can I measure the battery pack temperature?

I have the SOCmeter (Gary's version) but dont think that measures battery temperature. This week (in Portland) the temperatures have been flirting with high 90's, so the Leaf is cooling its heels inside the garage while i drive my ICE car to work. I want to get a real-time reading of battery pack temperature to reduce my stress levels!

If you are not driving it, why would there be stress?

The upcoming LEAFscan will provide the temperature data from the battery.

chennu, I'm stressing about it too. I had my wife move it twice today to keep it in the shade at all times. It's going to be right around the 100's for Thursday/Friday. Fortunately it should be back to 80 by Saturday. I've never seen 7 bars which is good, but apparently the high 6's might be enough to do damage. :\

If you are not driving it, why would there be stress?

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This is not exactly how I envisioned my EV experience! I am having second thoughts about keeping my Leaf (purchased). I tend my keep my cars until they die and dont want to have to continually worry about temperature and range. I already lose range in winter because of low temperature (and needing to keep the heater on). Having to worry about high battery temperature in the summer is ridiculous..

I've never seen 7 bars which is good, but apparently the high 6's might be enough to do damage. :\

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the fact that 6 and 7 have high overlap is also not very helpful! even though I have not driven it in 72 hours, the bars dont go down below 6 (which makes sense, since the battery cannot go down below ambient, but still - this is another aspect to worry about. Cars are meant to be driven and not babied!!!

Looks like mid nineties for the Puyallup area. I plan to use the LEAF as normal. About a 20 mile R/T in the morning, perhaps a few short runs in the afternoon. Remainder of time in the garage.

Without any scientific backing, I just don't think one or two days at elevated temperatures is going to be a battery killer.

There are sensors that can be attached to the battery - believe Tick Tock (?) has used them.

BTW, the cooling function of the climate control has been super during this hot spell, and at a miserly cost of energy.

ebill3 said:

Without any scientific backing, I just don't think one or two days at elevated temperatures is going to be a battery killer.

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That calls for an adult beverage. Cheers!

ebill3 said:

Looks like mid nineties for the Puyallup area. I plan to use the LEAF as normal. About a 20 mile R/T in the morning, perhaps a few short runs in the afternoon. Remainder of time in the garage.

Without any scientific backing, I just don't think one or two days at elevated temperatures is going to be a battery killer.

There are sensors that can be attached to the battery - believe Tick Tock (?) has used them.

BTW, the cooling function of the climate control has been super during this hot spell, and at a miserly cost of energy.

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agree, but with the lack of any hard info from Nissan, i need to rely on my own measurements. hence my question! I really would like to understand the relationship between ambient temperature and battery pack temperature and any tool which allows me to do that while the summer lasts! if i cannot find anything, then the Leaf is going to be garaged until temperature comes down to the 70s!

chennu said:

agree, but with the lack of any hard info from Nissan, i need to rely on my own measurements. hence my question! I really would like to understand the relationship between ambient temperature and battery pack temperature and any tool which allows me to do that while the summer lasts! if i cannot find anything, then the Leaf is going to be garaged until temperature comes down to the 70s!

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You are totally overthinking this.

Remember that as a general rule of thumb, for every 10C rise in temperature, the rate of capacity degradation over a time period will double.

3 days of 100F (38C) max temps instead of normal 80F (27C) temps might age your pack an extra 3-4 days than it would have otherwise otherwise. Big deal.

If you're really worried about it, park the car outside the garage over-night where it will generally be cooler by as much as 10F. Do this for a couple weeks and you'll have made up the high temps that you're currently experiencing (which are nothing compared to the 105-115F max 90F min temps Phoenix has seen so far for the month of August). Portland is on average 30F cooler than Phoenix so far this month - 100F vs 70F.

You're worrying WAY too much: this thread is a great example of how a few (unfortunate) heat issues are generating fear among folks that should be driving/enjoying their Leaf, NOT worrying about it! Just because your car hits 7TB once in awhile doesn't mean you're going to ruin your battery: QC alone will do that even in moderate temps. I don't see much of an issue in your part of the country with evening temps, so you shouldn't EVER have 7TB during night-time charging.

I've been at 6 bars the entire time I've had my Leaf (since late June) until earlier this week when it dropped to 5 for the first time. Ok it was also 60* F outside for the first time in forever. Obviously less than 2 months there is no sign of a problem. If it were at 7 for that entire time, then I'd be concerned.

BTW, cabin temp does make a difference in battery temp. When the windows are up and it's 100*+ then you get 7 bars. If the windows are down it stays at 6 bars, in my experience.

Just my 2 cents, here's your complimentary pick ax to poke holes.

I too think that you are all over thinking the situation. For comparison, it has been in the high 80s to high 90s for the past few weeks here in Northern California. A few months ago it hit 100 for a few days. Never once did the car hit 7 temp bars for me and never once did I drive it differently than I normally do.

Enjoy the car, seriously. Stop stressing about it being a high of 90 degrees for a few days or a few weeks out of the year.

drees said:

chennu said:

agree, but with the lack of any hard info from Nissan, i need to rely on my own measurements. hence my question! I really would like to understand the relationship between ambient temperature and battery pack temperature and any tool which allows me to do that while the summer lasts! if i cannot find anything, then the Leaf is going to be garaged until temperature comes down to the 70s!

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You are totally overthinking this.

Remember that as a general rule of thumb, for every 10C rise in temperature, the rate of capacity degradation over a time period will double.

3 days of 100F (38C) max temps instead of normal 80F (27C) temps might age your pack an extra 3-4 days than it would have otherwise otherwise. Big deal.

If you're really worried about it, park the car outside the garage over-night where it will generally be cooler by as much as 10F. Do this for a couple weeks and you'll have made up the high temps that you're currently experiencing (which are nothing compared to the 105-115F max 90F min temps Phoenix has seen so far for the month of August). Portland is on average 30F cooler than Phoenix so far this month - 100F vs 70F.

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I think the effects of parking cars in poorly ventilated garages at night, especially in very hot climates such as Phoenix, might eventually show up in as very significant in loss of battery capacity. If you drive in 110+ ambient, and then park in 100+ ambient at night, and add charging heating on top of that, you are keeping your battery at very high temperature continuously for many months at a time.

I've (nearly) always parked my car in an open carport, in a region where ~30-40 F Summer daily temperature variations are the norm (60-75 F lows, 90-105 F highs). I was always concerned how this daily temperature cycling of the battery itself, might effect capacity over time. But (so far) I don't seem to have lost the capacity some have reported, form areas with considerably lower daily peak temperatures.

As has been noted, the LEAF battery is uninsulated and seems to have very good heat transfer qualities.

Nissan seems to have wanted the heat generated by the battery to be easily released to its surroundings. but if you keep your LEAF enclosed in a "battery warmer" at night, this can't occur.

if your concern is to the point where you wont drive the LEAF, i hope you have it sitting at 40-60% SOC because if you dont its like being concerned over high crime in your area to the point that you wont go out at night but still leave your front door unlocked.

as for me? i lease and have decided to test the heat. more to follow

DaveinOlyWA said:

if your concern is to the point where you wont drive the LEAF, i hope you have it sitting at 40-60% SOC because if you dont its like being concerned over high crime in your area to the point that you wont go out at night but still leave your front door unlocked.

as for me? i lease and have decided to test the heat. more to follow

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yup. its at 40%

I am doing a heat charge teddy this week. What I plan to do is heat soak the car until tomorrow then charge it during the hottest part of the day to see what happens. My goal is to get a trend line going with 4 different data points and a 10-15 ° temperature spread. so far with 3 of the 4 recorded I am seeing the expected plus the unexpected. So stay tinged

chennu said:

DaveinOlyWA said:

if your concern is to the point where you wont drive the LEAF, i hope you have it sitting at 40-60% SOC because if you dont its like being concerned over high crime in your area to the point that you wont go out at night but still leave your front door unlocked.

as for me? i lease and have decided to test the heat. more to follow

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yup. its at 40%

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Stanton said:

Just because your car hits 7TB once in awhile doesn't mean you're going to ruin your battery: QC alone will do that even in moderate temps.

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Your evidence/proof that QCing alone will ruin your battery even in moderate temps is?
I have no idea where you came up with that, but it isn't true. Even the new manual says you can QC multiple times a day without damage. But leaving the battery pack fully charged for extended periods can definitely damage it.

LEAFfan said:

Stanton said:

Just because your car hits 7TB once in awhile doesn't mean you're going to ruin your battery: QC alone will do that even in moderate temps.

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Your evidence/proof that QCing alone will ruin your battery even in moderate temps is?
I have no idea where you came up with that, but it isn't true. Even the new manual says you can QC multiple times a day without damage. But leaving the battery pack fully charged for extended periods can definitely damage it.

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I think he meant that QCing can raise the battery temperature to 7TB, not ruin the battery.

Third party temp sensor.

1:

http://www.overstock.com/Home-Garden/Digital-Thermometer/3322936/product.html?cid=202290&kid=9553000357392&track=pspla&adtype=pla&kw=%7Bkeyword%7D" onclick="window.open(this.href);return false;

2:

http://www.amazon.com/dp/B00209B33C/?tag=hyprod-20&hvadid=15721793379&hvpos=1o2&hvexid=&hvnetw=g&hvrand=844860470367781448&hvpone=&hvptwo=&hvqmt=&ref=asc_df_B00209B33C" onclick="window.open(this.href);return false;

3:

http://www.amazon.com/Franklin-Titebond-Weathermaster-Crystal-43991/dp/B002ILOKDM/ref=sr_1_4?ie=UTF8&qid=1345164935&sr=8-4&keywords=caucking" onclick="window.open(this.href);return false;