REGEN off or limited every morning or after car off for a while

[Big Earl]

It still seems like something changed with the latest software releases. The algorithm seems to be different. I had my car all last winter and do not recall ever seeing the regenerative braking limited to this degree when it’s 47° outside

That's an interesting observation. Perhaps it's an adjustment to improve battery longevity.

47°F is approximately 8°C, which is the battery's active heating target according to the cooling system diagnostic screen on the MCU. It wouldn't surprise me if their battery engineers have determined that to be the point at which regen must be limited.

 

[fbitz777]

It still seems like something changed with the latest software releases. The algorithm seems to be different. I had my car all last winter and do not recall ever seeing the regenerative braking limited to this degree when it’s 47° outside

Unfortunately I got my car in April of '17, However I know we had 40's temperature then and like you I never had seen these warnings before the latest release.

It also seems to limit the charging power at SC..I could only get 50kw today and the same stall I was getting 90kw a few days ago. And this is after I drove 30 miles to "warm" battery up and SOC was at 50%.

 

[jlarmstr]

They chemistry and physics for this is due to Li plating. At cooler temperatures Li plates out in metallic form and no longer in ion form, thus degrading the performance of the battery (i.e. damaging the battery). The process is irreversible, therefore, the battery maintenance system restricts regenerative charging until the batter warms sufficiently to avoid damage.

Lithium-ion batteries: Phenomenon of 'lithium plating' during the charging process observed
What is Lithium Plating? - UPS Battery Center
Lithium plating in lithium-ion batteries investigated by voltage relaxation and in situ neutron diffraction - ScienceDirect

You can find dozens of studies on the process....