Capped regen even at below 90%

[metafor]

So it's getting colder in the bay area these days and perhaps that's the reason but I've noticed lately that my regen is capped at ~30kW or so nowadays (seems inconsistent) at various battery charge levels. Previously, it'd only be capped if I was at 100% or close -- which made sense, you can't charge a battery at 100%.

Now, I've gotten it at 50%, 90%, 80%, etc. I try to use the regen brakes almost all the time in order to reduce wear on the brakes as well as maximize energy efficiency. So this is particularly annoying for me. Is this an effect of the colder weather? v5.8 software? Both?

 

[ecarfan]

It's the cold weather we've had for the past two weeks. A bit unusual for early December in this area but not unheard of.

 

[scottf200]

So it's getting colder in the bay area these days and perhaps that's the reason but I've noticed lately that my regen is capped at ~30kW or so nowadays (seems inconsistent) at various battery charge levels. Previously, it'd only be capped if I was at 100% or close -- which made sense, you can't charge a battery at 100%.

When I get a Model X this will be a big and strange change for me. My Volt does normal regen at any SOC (i.e. morning at 100%(aka 87%)) and seemingly any temp as it worked last night at 3F.

 

[ecarfan]

When I get a Model X this will be a big and strange change for me. My Volt does normal regen at any SOC (i.e. morning at 100%(aka 87%)) and seemingly any temp as it worked last night at 3F.

How can a Volt provide regen at 100% SOC?

 

[darthvdr]

The cold definitely zapped efficiency from our MS. It was getting into the low 30s last night and as I was driving home we were getting into the 450Whs even while driving just 40mph. I pre-heated the car for 30 minutes prior to driving as well.

 

[strider]

Just set your charge timer to start later so it will finish charging closer to when you plan to leave*. That will have the battery warmed up and regen will work as normal.

*I wish Tesla would give us "departure-time" charge scheduling to make this simpler. The RAV-4 has it and it's a Tesla drive train/electronics so it must be possible.

- - - Updated - - -

How can a Volt provide regen at 100% SOC?

He means 100% in what we would call "standard mode", hence the "aka87%"

 

[rdrcrmatt]

double check that you are not in low regen mode.. I forgot I had set it to low once during a snow storm.

 

[voidptr]

The cold definitely zapped efficiency from our MS. It was getting into the low 30s last night and as I was driving home we were getting into the 450Whs even while driving just 40mph. I pre-heated the car for 30 minutes prior to driving as well.

My experience seems to show a crossing point where as the temperature drops, the Wh/mi goes up as you drive slower. The energy draw apart from the drive train to warm the car goes up is constant in time, not distance, and it becomes significant the colder it is. If you're doing highway speeds, the pack does a better job of keeping itself warm, while the heater's only switched on for 60s/mile instead of 90s or 120s/mile.

 

[metafor]

Interesting, I guess I never experienced cold weather with my S before, but I've never seen this happen prior to 5.8...

 

[cinergi]

So it's getting colder in the bay area these days and perhaps that's the reason but I've noticed lately that my regen is capped at ~30kW or so nowadays (seems inconsistent) at various battery charge levels. Previously, it'd only be capped if I was at 100% or close -- which made sense, you can't charge a battery at 100%.

Now, I've gotten it at 50%, 90%, 80%, etc. I try to use the regen brakes almost all the time in order to reduce wear on the brakes as well as maximize energy efficiency. So this is particularly annoying for me. Is this an effect of the colder weather? v5.8 software? Both?

Both. 5.8 (or 5.6, perhaps 5.0) is more aggressive with limiting regen when it's colder. I've had regen limitation showing when it's as high as 50F outside. Last winter it had to be more like 40F.

 

[stopcrazypp]

Isn't the cold regen limit orthogonal to SOC (as in it depends on the temperature, not the SOC)?

I would also like to point out the Bay Area has seen record cold temperatures in the last couple of days.

 

[GDH]

My regen was completely disabled this weekend when it was in the teens and boy did that suck having to use the brakes constantly.

 

[Btrflyl8e]

I saw regen limitation below 100% SOC for the first time a few weeks ago when we got to the low 50's as well.

 

[rlang59]

I saw regen limitation below 100% SOC for the first time a few weeks ago when we got to the low 50's as well.

Yeah I started noticing the regen limit when it started to be in the 50s.

 

[scottf200]

He means 100% in what we would call "standard mode", hence the "aka87%"

Correct. As well I think they use the two motors (without ICE on!) in this way as described by a GM person (on gm-volt)

You have come across a feature of the vehicle which protects the battery from overcharging. Under certain circumstances, the electric motors will resist one another to provide braking in addition to the friction brakes on the vehicle. In order to meet emission requirements, the Volt does not spin the engine, but uses clutch 2 in the drive unit to link both motors. When the vehicle is at low speeds, clutch 2 requires that the resultant planetary gearset speeds increase to compensate. You will hear the electric motors at higher speeds, which is certainly a change from their normally silent operation.

The Volt was validated using the steepest, longest descent in the nation, Pike's Peak. With a full battery, the volt can descend Pike's Peak without issue with a combination of friction brakes and the electric motors. This is part of the Voltec propulsion system ...

Again when I get a Model X this will be a big and strange change for me.

 

[strider]

Correct. As well I think they use the two motors (without ICE on!) in this way as described by a GM person (on gm-volt)

Ah, never knew that about the Volt. Thanks for posting!