Regen throttling on hill descent

[thelastdeadmouse]

Sorry, no pictures. This weekend I took a trip to Lake Placid NY and while there we drove to Keene NY. The descent from Lake Placid to Keene has a stretch that descends something like 1,600 feet in 5 miles. I started this stretch with a range around 230-240 miles. Just before I got to the end of this stretch I got a message that regen was being limited, and the gray bar that shows power or regen had turned to gray dots for about half of the left regen side. It took several minutes to go away entirely, but once I hit flat ground it started to gradually come back.

It ended up not being an issue, I barely needed to use the brake pedal because of the timing, but I was surprised that it kicked in so quickly. Has anyone else experienced this?

 

[chinnam3]

That depends on state of battery/charge level. Coming down slope will use regen and charge the battery. If battery is close to full, then with in few miles it gets full and you would receive that warning. Also this happens when you set the battery charge in trip mode with full charge or close to full charge.

 

[gregincal]

I've gotten it before. Back when I first got my car 6 months ago it came on every day on my commute, but it's gotten a lot better and I rarely see it now (I descend about 1500 feet on my commute in about 8 minutes). It happens even if the battery is only about 75% charged. I assume it's to prevent either the battery or some other component from overheating.

 

[thelastdeadmouse]

That depends on state of battery/charge level. Coming down slope will use regen and charge the battery. If battery is close to full, then with in few miles it gets full and you would receive that warning. Also this happens when you set the battery charge in trip mode with full charge or close to full charge.

I would have expected this if the size of the battery was getting close to full, but at 75% I wouldn't have expect to it start throttling that quickly. It'd be nice if the car's UI would give a number for instantaneous kW output or regen, it'd be interesting to see how the limited regen rate would compare to supercharging rate at the same state of charge.

 

[dgpcolorado]

You may see regen limiting a lot more when the battery is cool. Expect to see it often in winter when the battery management system limits both regen and acceleration to protect the battery, even at a fairly low state of charge. (Warming the battery, by charging just before leaving, can help.)