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So we all know that the Volt has a Thermal Management System (TMS) for the battery to keep it in the optimal operating range. The TMS requires cooling (I live in Florida, cold climates would obviously be different) provided by the A/C. So After driving for some amount of time, the battery heats from being discharged so I arrive home with the battery warm.

So my question, has anyone seen research or have thoughts if there would be an appreciable efficiency gain by waiting for the car to cool off (over a couple hours) before starting charging after getting home? Does this time waiting for it to cool itself prevent the A/C from cranking to do the same job? I know the TMS will have to turn on at some point for a full charge, but at least reduce it.

Also, I have noticed that the TMS seems to kick in after charging has completed to bring the temp back down. When the green light begins flashing indicating that charging has stopped, the compressor still seems to be on most times and I can only assume that this is cooling. Is there any harm in unplugging at this point (which causes the compressor to stop). It doesn't seem to just cool with the battery instead of house power so it seems like this would help in a small way. According to my TED, the full charge cycle takes about 13.5 kwh to charge the 10.3 kwh in the battery. I would like to improve on this, but have already done the obvious of using low gauge wiring from the panel to a L2 charger.

Both of these would presumably be small differences, but can make difference in the long run.
 

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If you know that you will not need the car until morning, then plugging in with the car set to delayed charge with a completion time of about when you will depart is the most efficient since a warm battery releases power more readily than a cold one.

I imagine that the car resists using power to cool the battery when it is not connected to the grid since drawing power heats the battery further. The battery will last longer if it is able to be kept within the optimal temperature range.

Interestingly the tesla disables regen when the battery is too cold since it does not want to charge a cold battery. It will warm the battery first if plugged in, then start to charge it. It only takes a few minutes of driving to warm the battery up enough to accept regen, so most people would never notice.
 

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Question for those of you that have Volts in warmer climates... I know that my garage can get pretty warm in the summer even here in southern Idaho. Has anyone ever had an issue with the A/C when in TMS mode with the car parked in a closed unconditioned garage? I would think that the TMS could add heat via the A/C to a garage that is already hot. At some point it would become too hot for the A/C to function properly. Granted the battery pack is probably a small heat load for the A/C, and well insulated, but wondering if any of the Florida/Texas/Arizona et al Volt owners have had any issues?
 

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High temperatures degrade battery life faster when the battery is fully charged. You definately should keep your car plugged in until you leave, so that it can keep the battery relatively cool.

GSP
 

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Guess I will find out when Texas starts to hit 110 F.
The times I left my old car in the sun with windows up the inside temp got to 160F.

I do plan to always keep it plugged in and try the IR 3M tint filter.

Its going to be strange driving now in Texas with the Volt in summer- I don't need to turn on the HEATER to get extra cooling
 

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Guess I will find out when Texas starts to hit 110 F.
The times I left my old car in the sun with windows up the inside temp got to 160F.

I do plan to always keep it plugged in and try the IR 3M tint filter.

Its going to be strange driving now in Texas with the Volt in summer- I don't need to turn on the HEATER to get extra cooling
I don't know if it made it to production but GM was talking about using low IR transmission glass. IR film would only help more but not that much if it is low IR transmittance to begin with.
 

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if mine isn't rolling down the road it is plugged in so it can operate any system it wants to maintain proper battery temp without using the battery to do so. this is what gm recommends and it's easier for me since i don't have to mess with anything.
 
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