Cooling

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GlennD

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The yammer heads are bemoaning the lack of water cooling on the leaf

The best any non active cooling can do is bring the battery to the outside temperature.

If you leave your 100 degree garage and it is 115 outside then cooling will actually increase the temperature.

Cooling works on an ICE because the gas explosions generate a temperature far above the outside temperature .

I agree Nissan screwed up in only considering cold operation but without active cooling nothing can achieve better than the outside temperature.
 
While I tend to agree in principle with what you said.. Even cooling with forced air from the outside is better than nothing. For one thing, I think 120 degrees (or somewhere around there) is the magic number where the cells start to degrade. Even in Arizona it rarely gets that hot for the ambient temperature. So if it were 115 degrees outside, air cooling might keep the batteries under that magic number. The second consideration is that we live in the age of microprocessors. There is no reason the system cannot be intelligent enough to know when the air temperature outside the car is hotter than the battery, hence don't turn the fan on.
 
I believe the liquid cooling actively heats and cools the battery when parked and connected. Not sure what happens if not connected, I think it still cools using the air conditioner but not sure if it uses battery power to heat.
 
LKK said:
I believe the liquid cooling actively heats and cools the battery when parked and connected. Not sure what happens if not connected, I think it still cools using the air conditioner but not sure if it uses battery power to heat.
Click to expand...

Wrong.
 
TonyWilliams said:
LKK said:
I believe the liquid cooling actively heats and cools the battery when parked and connected. Not sure what happens if not connected, I think it still cools using the air conditioner but not sure if it uses battery power to heat.
Click to expand...

Wrong.
Click to expand...

I know I'm not an expert on this subject. Would you mind clarifying my errors?
 
LKK said:
I know I'm not an expert on this subject. Would you mind clarifying my errors?
Click to expand...
You're right (though your post may be easy to interpret incorrectly). BEVs with liquid cooling use AC to cool the liquid before sending it to the battery pack to cool the pack.
 
The Leaf battery pack cools by conduction.. all the cell modules are tightly packed together to conduct heat to the steel skin of the battery case, where air will finish the job. The modules in the center of the pack will be the hottest. A retrofitted chilled cooler can be done by just cooling the battery case plus added external insulation.

I can see a double-skinned battery case where the brazed-on second skin forms a channel for the chilled antifreeze.. thus a conversion would need a new battery case, insulation, a freon-antifreeze chiller, a freon valve and a coolant pump.. AC is already standard in the Leaf. As a bonus the system can also be used to heat the battery with the new 2013 heat pump.
 
LKK said:
I believe the liquid cooling actively heats and cools the battery when parked and connected. Not sure what happens if not connected, I think it still cools using the air conditioner but not sure if it uses battery power to heat.
Click to expand...
Generally correct. An active TMS can cool the battery using the onboard AC and heat it using using an onboard heater. If plugged in then the power to do this can come from the grid. If not plugged in the power can come from the battery.

Unsure why Tony said this was wrong. The Leaf has the heating but not the cooling capability. Of topic but you also have to cool the power electronics.
 
From the Volt forum:
post #82
http://gm-volt.com/forum/showthread.php?14585-LEAF-starting-to-wilt" onclick="window.open(this.href);return false;

Solar_dave said:
"In a 104F AZ garage the TMS runs about 15 minutes every 4 hours or so. It draws about 800 watts for the duration of the TMS run. Also the TMS does continue to run after the charge cycle for about another 20 minutes. The TMS would account for 1-1.5 kWh per day per car."
 
SanDust said:
Unsure why Tony said this was wrong. The Leaf has the heating but not the cooling capability. Of topic but you also have to cool the power electronics.
Click to expand...


I thought we were talking about the LEAF which, as we know, has no cooling system of ANY kind... no fan, no AC, no liquid, no heat sinks, etc.

The conduction cooling that is frequently mentioned is nebulous at best. The battery pack is not even "heat sinked" to the body of the car.
 
Herm said:
From the Volt forum:
post #82
http://gm-volt.com/forum/showthread.php?14585-LEAF-starting-to-wilt" onclick="window.open(this.href);return false;

Solar_dave said:
"In a 104F AZ garage the TMS runs about 15 minutes every 4 hours or so. It draws about 800 watts for the duration of the TMS run. Also the TMS does continue to run after the charge cycle for about another 20 minutes. The TMS would account for 1-1.5 kWh per day per car."
Click to expand...

And maybe two or three peak demand kWh, when parked in the sun for eight hours, on a hot Summer day in Phoenix?

Has anyone tested Volt TMS energy use, in severe conditions?
 
edatoakrun said:
And maybe two or three peak demand kWh, when parked in the sun for eight hours, on a hot Summer day in Phoenix?
Click to expand...

I doubt its that much, GM is proud to say the insulation on the pack is expensive NASA type stuff. The Volt will discharge the pack down to 75% SOC (63% absolute since its never fully charged) in an attempt to keep the pack refrigerated.
 
Herm said:
edatoakrun said:
And maybe two or three peak demand kWh, when parked in the sun for eight hours, on a hot Summer day in Phoenix?
Click to expand...

I doubt its that much, GM is proud to say the insulation on the pack is expensive NASA type stuff. The Volt will discharge the pack down to 75% SOC (63% absolute since its never fully charged) in an attempt to keep the pack refrigerated.
Click to expand...

One reason I think kWh use may be fairly high, is that I expect the AC efficiency probably drops off quite significantly at very high temperatures, especially in a parked car, that does not receive the cooling benefit from airflow that a moving one does.

Even if you don't have to move much heat out of a well-insulated battery, it may take a lot of energy to do it.
 
Hi guys this is solardave from the Volt forums.

The Volt TMS is just as described in the previous posts. My measurements are from a TED (theenergydetective) and my conditions are in Phoenix in my garage which regularly reaches well over 100F, sometimes over 110F. Somewhat severe.

The Volt TMS draws 800-900 watts for about 10-15 minutes every few hours to lower the battery temps. Also after charging the TMS continues to operate for some time to bring the battery back to a reasonable temp, length of time is dependent, I think, on how long it charged and the ambient temp. You can hear it running during charge times as well.

My TED is open to the publice @ http://phx-solar.no-ip.info/" onclick="window.open(this.href);return false;
it will take a minute to load, and the graphing section light blue line is the pair of Volt Chargers we have. BTW we own a 2011 Diamond White and a 2012 Crystal Red.
 
solardave said:
Hi guys this is solardave from the Volt forums.

The Volt TMS is just as described in the previous posts. My measurements are from a TED (theenergydetective) and my conditions are in Phoenix in my garage which regularly reaches well over 100F, sometimes over 110F. Somewhat severe.

The Volt TMS draws 800-900 watts for about 10-15 minutes every few hours to lower the battery temps. Also after charging the TMS continues to operate for some time to bring the battery back to a reasonable temp, length of time is dependent, I think, on how long it charged and the ambient temp. You can hear it running during charge times as well.

My TED is open to the publice @ http://phx-solar.no-ip.info/" onclick="window.open(this.href);return false;
it will take a minute to load, and the graphing section light blue line is the pair of Volt Chargers we have. BTW we own a 2011 Diamond White and a 2012 Crystal Red.
Click to expand...
do you know to what temp Volt lower battery temp if car just sit in the garage? I think is true that will engage if temp 90F?
 
EdmondLeaf said:
solardave said:
Hi guys this is solardave from the Volt forums.

The Volt TMS is just as described in the previous posts. My measurements are from a TED (theenergydetective) and my conditions are in Phoenix in my garage which regularly reaches well over 100F, sometimes over 110F. Somewhat severe.

The Volt TMS draws 800-900 watts for about 10-15 minutes every few hours to lower the battery temps. Also after charging the TMS continues to operate for some time to bring the battery back to a reasonable temp, length of time is dependent, I think, on how long it charged and the ambient temp. You can hear it running during charge times as well.

My TED is open to the publice @ http://phx-solar.no-ip.info/" onclick="window.open(this.href);return false;
it will take a minute to load, and the graphing section light blue line is the pair of Volt Chargers we have. BTW we own a 2011 Diamond White and a 2012 Crystal Red.
Click to expand...
do you know to what temp Volt lower battery temp if car just sit in the garage? I think is true that will engage if temp 90F?
Click to expand...

Yeah it is someplace around that 80-90F we do hear it kick in even in the spring and fall.
 
TonyWilliams said:
I thought we were talking about the LEAF which, as we know, has no cooling system of ANY kind... no fan, no AC, no liquid, no heat sinks, etc.
Click to expand...
Got it. Yup, nothing really to deal with higher temperatures for the battery.
 
solardave said:
Hi guys this is solardave from the Volt forums.

The Volt TMS is just as described in the previous posts. My measurements are from a TED (theenergydetective) and my conditions are in Phoenix in my garage which regularly reaches well over 100F, sometimes over 110F. Somewhat severe.

The Volt TMS draws 800-900 watts for about 10-15 minutes every few hours to lower the battery temps. Also after charging the TMS continues to operate for some time to bring the battery back to a reasonable temp, length of time is dependent, I think, on how long it charged and the ambient temp. You can hear it running during charge times as well.

My TED is open to the publice @ http://phx-solar.no-ip.info/" onclick="window.open(this.href);return false;
it will take a minute to load, and the graphing section light blue line is the pair of Volt Chargers we have. BTW we own a 2011 Diamond White and a 2012 Crystal Red.
Click to expand...

Has anyone tested Volt TMS energy use, in higher ambient temperatures?

Some have reported significantly-elevated temperatures, at "battery height" above asphalt.

Do you have any other way to estimate total kWh use, in those severe conditions?

Obviously you can't use your TED when parked in a lot, in the sun for eight hours, on a 110 F+ Summer day in Phoenix.

Have you tried testing, at home?
 
solardave, the numbers you're reporting and what you're hearing from the Volt is for when it's plugged in. Do you ever hear the TMS when it's just parked and not plugged in?

It's not using that much energy to keep the pack cool, maybe a kWh for the day. We've heard that the Volt will use the battery to cool itself if the SOC is above some level. Is the level configurable? Seems like that would be a nice feature.
 

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