Cold Weather Charging: what really happened with MS not charging?

Aces-Truck

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WildhavenMI

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CyberGus

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It is true that a Lithium battery cannot be charged while frozen without significant damage. However, thermal management should be able to warm the pack sufficiently, even at far colder temperatures (particularly when connected to shore power).

The inability to charge at 19° is not an inherent limitation of EVs, it is a malfunction.
 

Crissa

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If the thermal management fails, it won't be able to charge.

No different than a car with a frozen radiator or engine block. It can happen. This is why ICE cars wear engine-block heaters in that sort of prolonged cold.

Don't let your car go without a charge in the cold.

If the battery refuses to charge, as long as it's about 30%, it'll survive being frozen. Lithium batteries may not function in the cold, but they aren't damaged by it.

-Crissa
 


CyberGus

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I was under the impression that the PTC heater was eliminated in the M3 design. Heat is generated from the drive motors by running them inefficiently, even when not moving.
 

android04

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My 2018 Model 3 PTC heater definitely doesn't take that long to heat up the cabin in -18 degree F (not counting wind chill). Probably takes 10 minutes to fully warm up the cabin. A few years ago we had -39 degree F temps (with no wind chill) and after sitting outside all night it did take a while to warm up the cabin to above 60 degree F, but it got to the 50 and 60 degree F range within 10 or 15 minutes.
 

android04

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I was under the impression that the PTC heater was eliminated in the M3 design. Heat is generated from the drive motors by running them inefficiently, even when not moving.
The newer Model 3s and all Model Ys (and newer S and X) all now use the heatpump instead of a PTC cabin heater. The heatpump is the AC compressor working in reverse with some valves to redirect refrigerant flow and move heat between cabin, battery pack, drive unit, and the environment.

In all Model 3/Y, the drive inverters for the motors can be driven in a way that generates heat in order to heat up the battery pack (in the older PTC heated Model 3s) or to heat up the cabin (in the newer heat pump vehicles). Tesla can generate heat through that inefficient mode whether the car is being driven or not. The older Model S/X had a dedicated battery heater that warmed up the battery coolant. The newer S/X probably work the same way that the newer 3/Y do, where the drive inverter is used to generate heat.
 


Bill906

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I was under the impression that the PTC heater was eliminated in the M3 design. Heat is generated from the drive motors by running them inefficiently, even when not moving.
There was a person on this forum years ago who claimed that is how it worked. I have not seen any evidence to support it, and have seen references to the resistive heater, which seems to have disproved it.
 

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There was a person on this forum years ago who claimed that is how it worked. I have not seen any evidence to support it, and have seen references to the resistive heater, which seems to have disproved it.
The heat pump can extract heat from the environment for the thermal management system, but efficiency drops with ambient temperature. Resistive heat must be added by some means, and older Tesla models definitely used a PTC heater.

However, eliminating a part by repurposing an existing part is a very Tesla thing to do.
 
 




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