battery temps

[cgaydos]

I have never seen 7 temperature bars here. Often 6 in the summertime and 5 most of the rest of the year. I have seen 4 sometimes in the middle of winter and 3 once or twice.

Matches our experience almost exactly. In summer it always starts the day at 5 (even on 90F days it cools below 60F at night here) but on days above 75F it'll hit 6 after a while then stay there the rest of the day.

 

[planet4ever]

Well, second day in a row that I saw 7 TB. I know this is nothing for the folk from Phoenix, but it's a bit disturbing to me. I got in the car at about 3:30, had 6TB and the car said the outside temperature was 105°F. My wife and I had the AC on at 77°, and after two short stops where she stayed in the car, AC running, the display jumped to 7 TB. It could be the AC, or perhaps the battery just catching up to the outside temperature. We got home a 5 PM after 10 miles of driving at 2.8 m/kWh. The outside temperature was still 103° and I was still at 7 TB.

Ray

 

[cgaydos]

Well, second day in a row that I saw 7 TB. I know this is nothing for the folk from Phoenix, but it's a bit disturbing to me. I got in the car at about 3:30, had 6TB and the car said the outside temperature was 105°F. My wife and I had the AC on at 77°, and after two short stops where she stayed in the car, AC running, the display jumped to 7 TB. It could be the AC, or perhaps the battery just catching up to the outside temperature. We got home a 5 PM after 10 miles of driving at 2.8 m/kWh. The outside temperature was still 103° and I was still at 7 TB.

Ray

First, 105F in Morgan Hill? I know from a court case in San Jose (2006) that this temp is very rare in that area. I can't remember any of my cars showing temps of over 101F in the 14 years I lived in the south bay.

Second, 2.8 m/kWh? Is this much lower than your usual mileage? Is this because of the A/C? I've found the LEAF A/C to be extremely efficient but then I've not seen anything close to your temps.

 

[UBUYGAS]

Had a cool night in April and didn't charge it that night and when I got into the Leaf it was at 4 bars for a few minutes, seen 5 many times. Now that the days are in the 80's and 90's it has been 6 bars. Never seen 7 yet.

 

[DaveEV]

I can't help it if it doesn't add up, but that's the facts. I believe I may be around 5-6% BC loss. I remember with my '11, after a 20% BC loss, the pack heated up much more quickly and higher.

Personally, I think your temperature readings are low. In the past, you've mentioned temp readings that have stayed near the overnight low even after having sat outside all day. That simply doesn't happen.

I got in the car at about 3:30, had 6TB and the car said the outside temperature was 105°F.

First, 105F in Morgan Hill? I know from a court case in San Jose (2006) that this temp is very rare in that area. I can't remember any of my cars showing temps of over 101F in the 14 years I lived in the south bay.

Yeah, ouch, that's really hot for the Bay Area, even south of San Jose.

But if it's any help, it looks like Phoenix was around 120F today and will be that way for the next couple days at least.

120F is about 10C warmer than 100F which is about 10C warmer than 85F. Thanks to Arrenhious's equation, right now in terms of calendar life, one day in Phoenix is like two days in Morgan hill which is like 4 days here on the coast.

My pack is only just above 80F right now. Got to 85F driving around in the "heat", luckily there's a marine layer just offshore that is keeping things cool by the coast. Still, it's not going to get much cooler - my garage simply doesn't cool off much and retains heat pretty well.

 

[planet4ever]

First, 105F in Morgan Hill? I know from a court case in San Jose (2006) that this temp is very rare in that area. I can't remember any of my cars showing temps of over 101F in the 14 years I lived in the south bay.

Well, NOAA shows the high as 101°F today, so the car may not be reporting accurately. I did speak to someone this evening who said their car reported the same thing today. I will point out that the NOAA measurements are taken at a station which, while only two (crow flight) miles from our house, is at a higher elevation than the main part of town and much closer to the hills.

Second, 2.8 m/kWh? Is this much lower than your usual mileage? Is this because of the A/C? I've found the LEAF A/C to be extremely efficient but then I've not seen anything close to your temps.

Over two plus years of LEAF driving I have averaged 4.0 m/kWh. Looking at a 4 week window around today's date I averaged 3.9 in 2011 and 3.6 in 2012. I've had my 2013 LEAF for two months now, and averaged 4.3 m/kWh for that time. That 2.8 number is falsely low, though, because as I stated it included two brief stops (total less than 5 minutes) where my wife stayed in the car with the A/C running.

On the other hand, see LEAFfan's post today to the "So, owners what range are you getting ?" thread. It may be that the 2013 A/C can't live up to the 2011-2012 reputation.

Ray

 

[LEAFfan]

Personally, I think your temperature readings are low. In the past, you've mentioned temp readings that have stayed near the overnight low even after having sat outside all day. That simply doesn't happen.

I'm just reading what the CAR CAN reports, so I don't see how it is reporting false temps. What I reported was that my TSs reported about ten degrees below ambient while the car is out and about. It is never out all day.

But if it's any help, it looks like Phoenix was around 120F today and will be that way for the next couple days at least.

Officially today it was 119F which is the first time in history that the high has been exactly 119F. Each day for the rest of the week is supposed to be a little cooler.

 

[DaveEV]

I'm just reading what the CAR CAN reports, so I don't see how it is reporting false temps. What I reported was that my TSs reported about ten degrees below ambient while the car is out and about. It is never out all day.

You have reported scenarios where the pack cools below ambient temperatures at night while in a garage unless I've read your reports wrong. That's physically impossible. And now you report temp gauge bars that get triggered about 10 degrees lower than expected.

It all points to inaccurate temperature readings through the LEAF Battery App on your car for some reason.

 

[Stanton]

I'm just reading what the CAR CAN reports, so I don't see how it is reporting false temps. What I reported was that my TSs reported about ten degrees below ambient while the car is out and about. It is never out all day.

You have reported scenarios where the pack cools below ambient temperatures at night while in a garage unless I've read your reports wrong. That's physically impossible. And now you report temp gauge bars that get triggered about 10 degrees lower than expected.

It all points to inaccurate temperature readings through the LEAF Battery App on your car for some reason.

Bingo! I think we're starting to see the differences (as in accuracy) between some of these CAN meters. I know my LeafDD seems to be reporting very accurate temp data (and it tracks well with the number of Temp Bars).

 

[GregH]

I'm just reading what the CAR CAN reports, so I don't see how it is reporting false temps. What I reported was that my TSs reported about ten degrees below ambient while the car is out and about. It is never out all day.

You have reported scenarios where the pack cools below ambient temperatures at night while in a garage unless I've read your reports wrong. That's physically impossible. And now you report temp gauge bars that get triggered about 10 degrees lower than expected.

It all points to inaccurate temperature readings through the LEAF Battery App on your car for some reason.

Bingo! I think we're starting to see the differences (as in accuracy) between some of these CAN meters. I know my LeafDD seems to be reporting very accurate temp data (and it tracks well with the number of Temp Bars).

Ok, so here's the rub. The ELM Leaf battery app is using a single linear approximation from the raw thermistor value from the car. This works fine in the moderate temperature range but is divergent from the true temperature at higher temps. I've reposted in the thread "Active CAN sampling" the latest confirmed information for temperatures in the range 13-43C.

I can't speak for your car, but mine moves to 7 TBs when the highest TS is 95.9F. It moves to 8 TBs at 103.5F. I've only seen 9 once and that was after a QC in 100 degree heat and wasn't there to see the tripping point from 8-9, but my highest TS was 112F that day.

Jim was kind enough to share with me the equations he's using on the battery app... here's how it works out.
So LEAFfan saw 7TB at 95.9F on the battery app. Working backward that's a raw value of 365 which is actually 36.0C or 96.8F
8TB was at 103.5 on the battery app. Working backward that's 323 raw which is actually about 41.15C or 106F.
From this I would guess the trigger points are 36C and 41C since the car doesn't seem to use the raw thermistor value for actions, but merely to calculate degrees C (no decimal point) from which it makes decisions.

 

[GRA]

First, 105F in Morgan Hill? I know from a court case in San Jose (2006) that this temp is very rare in that area. I can't remember any of my cars showing temps of over 101F in the 14 years I lived in the south bay.

Well, NOAA shows the high as 101°F today, so the car may not be reporting accurately. I did speak to someone this evening who said their car reported the same thing today. I will point out that the NOAA measurements are taken at a station which, while only two (crow flight) miles from our house, is at a higher elevation than the main part of town and much closer to the hills.

Ray

Expect the official temp to be lower on a hot day. Official temps are taken in a vented, white painted box 5 feet off the ground, not down where the temp sensor of a Leaf sits, much closer to hot pavement. I know Morgan Hill and points south are often hotter than San Jose; IIRR, King City gets the highest temps in Monterey county (or is that San Benito county)? Driving back from diving in Monterey, there always seems to be a Sunday or two each summer where it's officially 102+ in Gilroy or Morgan Hill; highest I recall was 106, and I was very glad to use A/C from Castroville until I got home.

 

[ksnogas2112]

Last summer was record breaking heat even for us (Kansas). I hit 7 TB quite a few times and assume that many of the 6 TB were flirting with the 7 TB but got turned down. We had ambient air temps in the 95-110*F most of the days from the end of June until the middle of Sept. I never saw 5 TB until Oct last year (Bought in June). Been at 6 TB since it started warming up about 2 weeks ago until this morning (95* last Wed and 65* this morning).

14k miles in first year with no noticeable degradation. Car's getting it's 1 year check right now. I wouldn't worry about flirting with 7 a few days but if it's extended I would definitely worry and if you're in Phoenix....well panic is a strong word but I would investigate methods to cool the pack (fans, driving through puddles, air conditioned garage, swamp cooler under car, divine intervention).

On that note, does anyone have an opinion about the default standard cold weather package affecting the battery in hot climates? Basically I'm wondering if having the skid plate under the car that's part of the cold weather package would increase the time to dissipate heat from the battery by providing insulation? Where I'm at we need the cold weather package in the winter for the snow and cold but need the battery to cool during the stupid summer. Just really glad this summer has been mild so far for us. Did I mention it snowed in May??

 

[GerryAZ]

I suspect the insulation associated with the cold weather package may increase the thermal resistance between the battery and ambient. This would help in some cases and hurt in others. I am glad my 2011 does not have the insulation. I hit 10 temperature bars on the 119 F day (Saturday) after 50 miles of mostly freeway driving, 3-1/2 hours of L2 charging, some suburban driving, and finally a few more miles on the freeway. It was back down to 7 bars the next morning.

Gerry

 

[mikefox]

I found the temp bars ranging in between 6 bars to 8 bars on the way to my friends house visit at this weekend without undergoing any charging. The temperature displayed was 125 F. The highest it has ever reached was 8.5 bars after a QC last weekend.

 

[RegGuheert]

On that note, does anyone have an opinion about the default standard cold weather package affecting the battery in hot climates? Basically I'm wondering if having the skid plate under the car that's part of the cold weather package would increase the time to dissipate heat from the battery by providing insulation?

All LEAFs have the extra plate below the battery. I'm pretty sure it is there to keep dirt off the bottom of the battery and to direct the flow of air along the bottom surface of the battery to reduce the thermal resistance from ambient while driving. Unfortunately, that plate certainly increases the thermal resistance to ambient when parked since it adds a dead-space.

 

[GetOffYourGas]

The temperature displayed was 125 F.

Battery notwithstanding, that is d@mn hot. I had read about the record heat wave, and am glad I'm not in the southwest right now. Stay cool out there, guys!

 

[Stanton]

I found the temp bars ranging in between 6 bars to 8 bars on the way to my friends house visit at this weekend without undergoing any charging. The temperature displayed was 125 F. The highest it has ever reached was 8.5 bars after a QC last weekend.

Not to sound like a smart-a**, but how could you tell it was 8 and a HALF bars??
Was any highway driving (what speed?) included in that trip? Parked on hot pavement? Just wondering what (besides ambient temp) drove you to 8TB since you said you didn't charge.

 

[UBUYGAS]

Temps were at 95 today and felt like 101 to 104 depending where you were, Temp Bars hit 7 today. First time I ever saw 7 Bars

It stayed 7 only for a little bit, as I got moving it changed down to 6.

 

[GregH]

Ok, so here's the rub. The ELM Leaf battery app is using a single linear approximation from the raw thermistor value from the car. This works fine in the moderate temperature range but is divergent from the true temperature at higher temps. I've reposted in the thread "Active CAN sampling" the latest confirmed information for temperatures in the range 13-43C.

I can't speak for your car, but mine moves to 7 TBs when the highest TS is 95.9F. It moves to 8 TBs at 103.5F. I've only seen 9 once and that was after a QC in 100 degree heat and wasn't there to see the tripping point from 8-9, but my highest TS was 112F that day.

Jim was kind enough to share with me the equations he's using on the battery app... here's how it works out.
So LEAFfan saw 7TB at 95.9F on the battery app. Working backward that's a raw value of 365 which is actually 36.0C or 96.8F
8TB was at 103.5 on the battery app. Working backward that's 323 raw which is actually about 41.15C or 106F.
From this I would guess the trigger points are 36C and 41C since the car doesn't seem to use the raw thermistor value for actions, but merely to calculate degrees C (no decimal point) from which it makes decisions.

Here's an odd data point.. So in my 2012 I saw the temp get up to 36.8 and still no 7th TB.. but at the moment I'm in a 2013 rental car and glanced down to see 7 TBs at 36.6C... ?? It probably came on earlier and I didn't notice. Now it's possible that 36ish is right on the edge and other factors determine the 7th TB turning on.

Or.. is it possible the 2013s are more sensitive? Ie now that Nissan knows a bit more about how high temps kill batteries is it possible the 2013s bring on the extra temperature bars earlier? I'll pay closer attention today.

 

[Stanton]

There's definitely some hysteresis going BOTH WAYS on the temp bars. That is, I've seen similar high temps @6TB that were still @7TB on the way down. It's possible one of the triggers requires ALL temp sensors to hit a certain level while the other doesn't; just not sure which is which until we see some more 100+ degree days where I can start taking some temp snapshots.