Do motors actually heat the battery?

[HaveBlue]

I think technically it's the inverter/speed controllers that generate the heat and not the motors. They are also cooled and convert DC to 3 phase AC and vice versa. They are mounted to the motors. You can generate heat by brake torquing the motors to dead lock the inverters but I don't think the motors get hot in comparison to the inverters. The Duals cool in an oil bath that is circulated when the motor spins.

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[Zoidz]

They do but they primarily function as heaters to precondition in advance of fast charging. The cooling system otherwise doesn’t actively cool or heat the batteries.

I think technically it's the inverter/speed controllers that generate the heat and not the motors. They are also cooled and convert DC to 3 phase AC and vice versa. They are mounted to the motors. You can generate heat by brake torquing the motors to dead lock the inverters but I don't think the motors get hot in comparison to the inverters. The Duals cool in an oil bath that is circulated when the motor spins.

According to the this article, as well as others I have read over the years, all indications are that the motors as well as the inverters are used to quickly generate heat, and the heat is used to actively heat the battery when necessary, not just when preapring to charge. I'm pretty sure I've read that the AC is also used to cool the battery when necessary.

“In extremely cold conditions we use some battery energy to keep the cells in our battery above 14°F to provide controlled vehicle performance,” said Laura, who work as a Control Integrations Engineer.

“Some EVs have electrical heaters to heat the battery up, which is another component — more cost, more mass, and a drain on electrical supply. Instead, we’re using our inverter and motor to generate heat — even while stationary, our traction system can generate substantial heat for the battery,” she said.

 

[Riviaenz]

According to the this article, as well as others I have read over the years, all indications are that the motors as well as the inverters are used to quickly generate heat, and the heat is used to actively heat the battery when necessary, not just when preapring to charge. I'm pretty sure I've read that the AC is also used to cool the battery when necessary.

“In extremely cold conditions we use some battery energy to keep the cells in our battery above 14°F to provide controlled vehicle performance,” said Laura, who work as a Control Integrations Engineer.

“Some EVs have electrical heaters to heat the battery up, which is another component — more cost, more mass, and a drain on electrical supply. Instead, we’re using our inverter and motor to generate heat — even while stationary, our traction system can generate substantial heat for the battery,” she said.

Yes totally agree and I’ve experienced when the battery cools to extremes (30s and lower) and at those battery temps the system does use bleed heat to help warm it up. But generally the heat energy of the motors isn’t used to maintain battery temps. It’s especially evident if for example you start your drive with the battery in an optimal temp range (70F for example) and drive with an ambient in the 20s. While the battery at a high SoC the battery will cool gradually. It’s not until you start dipping into the 30%s or lower that the battery starts warming up. That’s purely a function of battery chemistry/physics coming into play as higher current flow is required at lower voltages. That demand/reaction in itself warms the battery naturally.

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