Reduced regenerative braking

[blanchardmark]

2025 Air Pure - in the mountains of W NC, regen is severely reduced when descending steep hills. Lucid mobile tech came out and drove it. The issue was new to him, but he checked with engineers, and came back with this explanation:

“So what I am told is there is an inverter on the drive motor that takes the energy during regenerative braking and puts it back into the battery, so it is not the battery that the battery management system is protecting, it is the inverter. If the temperature of the inverter gets too high due to the excessive regeneration it will limit the amount of energy it will convert to protect the inverter from overheating. Unfortunately this is normal operation for the vehicle.”

Disappointing, and somewhat of a safety issue as you never know how much regen braking to expect. I realize the charge meter gives an indication with its solid/dashed lines, but when you’re navigating sharp corners on a steep hills, you don’t always have time to look at the gauges.

I assume this would be less of an issue with the Touring and GT, with their larger combined hp motors/generators and, hence, larger regen capacities.

 

[Blue Lectroid]

2025 Air Pure - in the mountains of W NC, regen is severely reduced when descending steep hills. Lucid mobile tech came out and drove it. The issue was new to him, but he checked with engineers, and came back with this explanation:

“So what I am told is there is an inverter on the drive motor that takes the energy during regenerative braking and puts it back into the battery, so it is not the battery that the battery management system is protecting, it is the inverter. If the temperature of the inverter gets too high due to the excessive regeneration it will limit the amount of energy it will convert to protect the inverter from overheating. Unfortunately this is normal operation for the vehicle.”

Disappointing, and somewhat of a safety issue as you never know how much regen braking to expect. I realize the charge meter gives an indication with its solid/dashed lines, but when you’re navigating sharp corners on a steep hills, you don’t always have time to look at the gauges.

I assume this would be less of an issue with the Touring and GT, with their larger combined hp motors/generators and, hence, larger regen capacities.

You are correct. Having two motors / inverters to do the work theoretically doubles the capacity for regeneration.

 

[Bobby]

2025 Air Pure - in the mountains of W NC, regen is severely reduced when descending steep hills. Lucid mobile tech came out and drove it. The issue was new to him, but he checked with engineers, and came back with this explanation:

“So what I am told is there is an inverter on the drive motor that takes the energy during regenerative braking and puts it back into the battery, so it is not the battery that the battery management system is protecting, it is the inverter. If the temperature of the inverter gets too high due to the excessive regeneration it will limit the amount of energy it will convert to protect the inverter from overheating. Unfortunately this is normal operation for the vehicle.”

Disappointing, and somewhat of a safety issue as you never know how much regen braking to expect. I realize the charge meter gives an indication with its solid/dashed lines, but when you’re navigating sharp corners on a steep hills, you don’t always have time to look at the gauges.

I assume this would be less of an issue with the Touring and GT, with their larger combined hp motors/generators and, hence, larger regen capacities.

If there is a certain road you are concerned about, like the sharp corners on the steep hill you mentioned, perhaps it's best for you to turn regeneration off entirely and rely on the mechanical brakes.

 

[knewman]

I've encountered that same message about limited regen when first starting the vehicle in the morning. Is there a temperature window the inverters must reach to avoid the scenario? Do I need to heat them up?

 

[Blue Lectroid]

I've encountered that same message about limited regen when first starting the vehicle in the morning. Is there a temperature window the inverters must reach to avoid the scenario? Do I need to heat them up?

In the morning when the batteries are cold, Regen is limited to protect the batteries.

 

[blanchardmark]

In the morning when the batteries are cold, Regen is limited to protect the batteries.

Yes, regen can be limited when the batteries are cold, but this is a separate issue from that (it happens whether they are warm or cold). It’s also not related to the reduced regen that happens when the batteries are fully charged.

 

[Blue Lectroid]

Yes, regen can be limited when the batteries are cold, but this is a separate issue from that (it happens whether they are warm or cold). It’s also not related to the reduced regen that happens when the batteries are fully charged.

I know. I was not referring to your original post…THAT is from the need to protect the inverter. @knewman was asking about why Regen is limited in the morning when the car is cold…