Garage Ventilation

[surfingslovak]

Battery temperature this morning, 5 bars, air temperture 69.0F.

I love the sight of five bars in the morning.

 

[DaveinOlyWA]

what is the temp parameter for TB #6 and is there any leeway as far as bars coming and going?

 

[surfingslovak]

what is the temp parameter for TB #6 and is there any leeway as far as bars coming and going?

It's between 74.3 and 80.6 F depending on pack degradation, and yes, I have observed some hysteresis. Although it could have been due to the thermal mass of the battery, since I used a laser surface probe, not the internal temp sensor.

 

[DaveinOlyWA]

what is the temp parameter for TB #6 and is there any leeway as far as bars coming and going?

It's between 74.3 and 80.6 F depending on pack degradation, and yes, I have observed some hysteresis. Although it could have been due to the thermal mass of the battery, since I used a laser surface probe, not the internal temp sensor.

hmmm TB 6 reading seems a bit low. but essentially all the time TB 7 is on your pack is degrading. i see TB 6 during summer frequently and every time i QC. 7 i have not seen

wondering if a temp bars should have had a color gradiant that moves from green to orange at TB 7?

 

[DaveEV]

but essentially all the time TB 7 is on your pack is degrading.

Hate to be pedantic, but it does not matter what temp bar you see, you battery pack is degrading. The more temp bars you see, the faster it's degrading.

 

[surfingslovak]

but essentially all the time TB 7 is on your pack is degrading.

Hate to be pedantic, but it does not matter what temp bar you see, you battery pack is degrading. The more temp bars you see, the faster it's degrading.

Yes, exactly! There is no magic number, sorry.

However, if you were looking for a line in the sand, perhaps you could take the 86 F cutoff Volt engineers use when determining whether they should waste battery power to cool the pack or not. It's a bit arbitrary, and likely an engineering trade-off, but it also tells us that when hard-pressed, Volt engineers thought 86 F was not that bad. This temperature corresponds to the midpoint of the sixth battery bar in the Leaf.

Having said that, lower temperatures would be always preferable for long battery life.

 

[DaveinOlyWA]

but essentially all the time TB 7 is on your pack is degrading.

Hate to be pedantic, but it does not matter what temp bar you see, you battery pack is degrading. The more temp bars you see, the faster it's degrading.

hmm, doesnt sound like you hate it all that much. i think there is some basic information that needs to be taken for granted. this is one of those things i think

 

[DaveinOlyWA]

but essentially all the time TB 7 is on your pack is degrading.

Hate to be pedantic, but it does not matter what temp bar you see, you battery pack is degrading. The more temp bars you see, the faster it's degrading.

Yes, exactly! There is no magic number, sorry.

However, if you were looking for a line in the sand, perhaps you could take the 86 F cutoff Volt engineers use when determining whether they should waste battery power to cool the pack or not. It's a bit arbitrary, and likely an engineering trade-off, but it also tells us that when hard-pressed, Volt engineers thought 86 F was not that bad. This temperature corresponds to the midpoint of the sixth battery bar in the Leaf.

Having said that, lower temperatures would be always preferable for long battery life.

*but* the battery tutorial makes a blanket statement in which a recommended temp range should be between 10 to 30C and that above 30C a measurable amount of increased degradation is present

 

[surfingslovak]

wondering if a temp bars should have had a color gradiant that moves from green to orange at TB 7?

You know, that's an interesting idea! When you look at how many folks get spooked when they reach the two red bars on the SOC gauge, this could be both effective and educational.

 

[surfingslovak]

*but* the battery tutorial makes a blanket statement in which a recommended temp range should be between 10 to 30C and that above 30C a measurable amount of increased degradation is present

Which tutorial, not the Leaf owner's manual? I think that one is deliberately kept vague.

Like many other Leaf owners, I've read many battery tutorials, studies, papers and even other forums over the past year. They sometimes contradict each other, and it's difficult to get reliable information out of it. But I think we are getting somewhere.

Does the battery degrade faster when it's over 86 F (30 C). Most definitely! How much faster than when it's at 50 F (10 C)? Honestly, I don't know. We can look at some of these sources and work out if the relationship was logarithmic or not, but that's the best we can hope for without a lab test performed with the exact cells the Leaf is using.

 

[DaveinOlyWA]

*but* the battery tutorial makes a blanket statement in which a recommended temp range should be between 10 to 30C and that above 30C a measurable amount of increased degradation is present

Which tutorial, not the Leaf owner's manual? I think that one is deliberately kept vague.

I've read many battery tutorials, studies, papers and even other forums over the past year. They sometimes contradict each other, and it's difficult to get reliable information out of it. I think we are getting somewhere. Does the battery degrade faster when it's over 86 F (30 C). Most definitely! How much faster than when it's at 50 F (10 C)? Honestly, I don't know. We can look at some of these sources and work out if the relationship was logarithmic or not, but that's the best we can hope for without a lab test performed with the exact cells the Leaf is using.

i think i am getting my threads mixed up

http://batteryuniversity.com/learn/article/types_of_lithium_ion" onclick="window.open(this.href);return false;

was link posted by "someone" somewhere on this site...best i can tell ya.

 

[garygid]

How about opening the garage door about two or three inches after the
evening air has cooled below the temperature inside the garage?

The warmer air inside the garage should flow out at the top of the
garage door while the cooler air flows in through the bottom opening.

 

[pchilds]

How about opening the garage door about two or three inches after the
evening air has cooled below the temperature inside the garage?

The warmer air inside the garage should flow out at the top of the
garage door while the cooler air flows in through the bottom opening.

Last year, I opened the garage door a foot or more, until midnight and I am down 11%, I need to be more proactive.

 

[Stanton]

Based on comments here, I finally broke down and bought a "shop fan" to run in the garage at night when I'm charging my Leaf; I think it's helping. When it starts hitting 100+F in the afternoon, I go home with 7TB and my garage is 90+F. The problem is, I can't shake that seventh bar between the still air of the garage combined with charging. Even though I do an end-only timer for 6AM, I was coming out to 7TB when leaving for work. When I noticed it dropped to 6TB not long after arriving at work, I knew the garage was part of the problem. I don't want to park my Leaf on the driveway, leave my garage door cracked, or install a vent system, so I tried the fan. I aim it right under the car and it seems to lower the garage temp a bit more than 5 degrees, which looks to be enough to get me off that seventh bar in the morning (I thought I was right on the edge). I guess I'll keep it up until temps get back under 100F; whatever the fan is costing me in electricity is a small price to pay to (possibly) extend my battery life.

 

[Nubo]

Based on comments here, I finally broke down and bought a "shop fan" to run in the garage at night when I'm charging my Leaf; I think it's helping. When it starts hitting 100+F in the afternoon, I go home with 7TB and my garage is 90+F. The problem is, I can't shake that seventh bar between the still air of the garage combined with charging. Even though I do an end-only timer for 6AM, I was coming out to 7TB when leaving for work. When I noticed it dropped to 6TB not long after arriving at work, I knew the garage was part of the problem. I don't want to park my Leaf on the driveway, leave my garage door cracked, or install a vent system, so I tried the fan. I aim it right under the car and it seems to lower the garage temp a bit more than 5 degrees, which looks to be enough to get me off that seventh bar in the morning (I thought I was right on the edge). I guess I'll keep it up until temps get back under 100F; whatever the fan is costing me in electricity is a small price to pay to (possibly) extend my battery life.

Makes sense. The fan disturbs the "boundary layer" of air near the metal. Warm as it may be, the ambient air in the garage is cooler than the airspace within an inch or so of the metal in still air, since it's already taken on some heat from the pack.

 

[smkettner]

wondering if a temp bars should have had a color gradiant that moves from green to orange at TB 7?

You know, that's an interesting idea! When you look at how many folks get spooked when they reach the two red bars on the SOC gauge, this could be both effective and educational.

Especially since the SOC bars have no color differentiation. The two red marks are CAPACITY bars.

 

[pchilds]

I added a security screen to the side garage door, the wife had a cow, when she learned I was leaving the door open all night. :shock:

The high yesterday was 110F+, the garage was 76F at 07:00 this morning. Didn't hit 5 bars this morning, it has to drop to 74F to get 5 bars.

 

[TickTock]

I installed a swamp cooler into an existing window and it is working well. It took over 24 hours to finally get the temperatures down but now it is very bearable - never getting above 90 (had been seeing up to 110 before). I had one problem with the Home Depot unit - kept tripping the GFI. Upon inspection I found they put an unprotected outlet inside the unit in the spash zone. Stupid. Pushed it back into the unit and duct taped the resulting opening closed - seems to have done the trick. Interested in feedback on my ventilation choice. To keep the garage secure, I simply opened the attic access hatch so the hot air is push up into the attic. Any reason I shouldn't be doing this? I figure pushing the attic air out the O'Hagen vents should help with the household cooling load if anything. I have fiberglass insulation in case that is a factor with sending humid air up there.

 

[edatoakrun]

... I simply opened the attic access hatch so the hot air is push up into the attic. Any reason I shouldn't be doing this? I figure pushing the attic air out the O'Hagen vents should help with the household cooling load if anything. I have fiberglass insulation in case that is a factor with sending humid air up there.

I'd suggest that you should keep an eye on your attic, for any signs of new residents, that you might not want as "neighbors".

The higher humidity (and possibly condensation, if you have cold water pipes, AC ducts, etc., in your attic) might prove attractive to everything from mold, to insects and rodents.

 

[Nubo]

...To keep the garage secure, I simply opened the attic access hatch so the hot air is push up into the attic. Any reason I shouldn't be doing this?...

Building codes often require the garage space to be firewalled from the rest of the house. This is for protection from fire, and carbon monoxide. Also, if I understand swamp coolers, you are humidifying the garage air, so that moisture will eventually be entering the attic, which you definitely don't want.