Regen and traction control disabled warning

Regen and traction control disabled warning

Upon leaving an appointment in Seattle my S presented warnings;
both the traction control and regen were disabled!

Lucky, I was several blocks from the service center but the drive
there was strange (especially the lack of regen). The lads at the service
center had me do the two button reset and everything returned to normal
(actually, "wonderful" would be a better choice of word)

If it happens just reset.

bill | December 10, 2013

I got the 'regen disabled' warning a couple of days ago shortly after leaving my house (it was about 25F outside). I was worried it would require a trip to the service center, or maybe a reboot would fix it. As it happened the regen starting working again just before I arrived at the office (an 11 mile trip).

I'm guessing that because the battery gets heated when it's cold outside, at very low temperatures the regen might get disabled as part of the charging/heating scheme?

I've noticed that my average kWH/mi has about doubled during the past week with the cold temperatures. It seems to take about 10-20 minutes (depending on temperature) for the battery heating to switch off, and while it's on it's drawing > 900 kWH/mi.

AmpedRealtor | December 10, 2013

When the battery is cold, its ability to accept a charge quickly is severely hampered. Regen dumps a lot of current back into the battery very quickly, making it an ill fit for a cold battery. The solution Tesla has chosen is to limit or disable regen until the battery is better able to accept the charge without incurring damage.

Some have suggested that future updates to Model S should allow full regen with a cold battery as follows. Until the battery has achieved its target temperature, the regen current can be used to help heat the battery instead. I think that's certainly preferable to losing all of that energy by disabling regen altogether.

Brian H | December 10, 2013

Are you plugged in at night? Charging warms the battery, so if you set the timer and the amperage to be just finishing as you leave, you should save all the heating range loss and have full regen.