Charged battery for 6+ hours right up until leaving, still had regen dots?!

[Mike Hawk]

Enclosed garage, 52f according to dash thermometer .

I scheduled charging to start @ 2am. 245v @ 16a, aka NEMA 6-20. Left @ 8am with 30 min charging left to hit my defined limit (90%).

Still have dots. What gives?

 

[1.21GW]

cold weather. not fun.

I try to do the same when charging and I am never fully able to get the dots to go away. Most of my drives these days are "regen limited". These cars are very sensitive to anything colder than San Francisco weather.

 

[SD_Engnr]

I thought that it's a function of both temperature and "fullness" of the battery?

For example, it could be in the 70's here in SoCal, and with a battery at 90% or more, I expect to see the regen dots. Once the battery is down in the low 80th percentile, they go away, unless, of course, it's cold outside. I appreciate slightly limited regen, as it allows me to use the brakes every now and then.

 

[Mike Hawk]

I'll set my limit to 80% and report back tomorrow.

 

[Big Earl]

Charging the battery at 16 amps (4 kW) won't generate enough heat to completely restore regen.

 

[Petrlol]

I agree with it could be a combination. I've seen limited Regen on warm days until under 82% or so. I'm also not convinced 4kw is enough to warm completely. It'll be interesting to see you charge for a few hours and land at 80%.

On a side note 60f seems to be the magic number where most Regen limitations disappear after a few minutes of driving.

 

[1.21GW]

I don't think I've driven my car in 60+ degree weather yet... hmm. can't wait till summer.

also, i charge at 11 kW and still see the dots. Charging helps but not completely and 4kW is not likely going to do that much.

 

[Mike Hawk]

Well no scheduled charging benefits for me then it sounds like. Poo poo... I don't get 'off hours' rates either, my rate is $0.0807 kWh year round (which also makes it pointless from a financial standpoint to look into solar/wind )

Only slight benefit to scheduled charging would be to not overload the grid a slight amount right @ evening time when everyone is getting home from work and firing up their lights/computers/ranges/ovens/HVAC etc.

I do wish there'd be an update where you request the time of day you want your car to be fully charged and then the angry pixies figure out when to turn on charging. Would make it so I don't have to count hours backwards on my fingers

 

[ewoodrick]

AFAIK, 90% and cool temps will give reduced regen. preheating won't help.

 

[sdrevik]

I charge in a 50 degree garage, schedule it to charge 3am to 6am, up to 70%, most mornings I have limited regen.

 

[viperssd]

AFAIK, 90% and cool temps will give reduced regen. preheating won't help.

I didn't know that, I thought preheating the cabin would also start heating of the battery

 

[Sophias_dad]

I do wish there'd be an update where you request the time of day you want your car to be fully charged and then the angry pixies figure out when to turn on charging. Would make it so I don't have to count hours backwards on my fingers

Get the "Dashboard for Tesla" app and "Smart Charging" as an add-on. That's like $18 for the life of your phone, and will do your figuring for you. (It only exists for Android, I understand)

 

[StealthP3D]

cold weather. not fun.

I try to do the same when charging and I am never fully able to get the dots to go away. Most of my drives these days are "regen limited". These cars are very sensitive to anything colder than San Francisco weather.

My ICE cars were even more sensitive to the cold. Even at 60 degrees I had no regen! And my MPG would go way down. Wait, I NEVER had ANY regen with my ICE cars! In the Model 3, even when regen limited from a cold battery, I usually have enough regen that I can descend reasonably steep grades and drive in traffic without using my friction brakes. It has to be really cold for the regen to be so limited that I have to touch my brakes more than a light tap here and there as I pull up to a stop.

 

[Rocky_H]

I didn't know that, I thought preheating the cabin would also start heating of the battery

Well, there's heating, and then there's heating. It's not just one level. Yeah, if the battery is at 6 degrees, it will not charge at all when it's that cold, and it must heat the battery up some to get it to a level where it can safely charge at all. But if you're looked at graphs of these things of amps versus temperature, you'll see that it's a gradually changing curve. So it will be up to some "not quite cold" level, but it's not going to heat the battery all the way up to some toasty 80 degrees or something for just a 7kW low power charging at home. But remember that regen can be up near 50 or 60kW maximum, and it's certainly not warm enough to allow that. That would be a big waste of energy for just some low power home charging.

 

[StealthP3D]

So it will be up to some "not quite cold" level, but it's not going to heat the battery all the way up to some toasty 80 degrees or something for just a 7kW low power charging at home. But remember that regen can be up near 50 or 60kW maximum, and it's certainly not warm enough to allow that. That would be a big waste of energy for just some low power home charging.

Exactly! And the Model 3 will never heat the battery up for the sole purpose of giving you a higher level of regen because that would be similarly wasteful (regen would never give back the amount of energy it took to heat the pack up to allow the regen in the first place).

 

[Rocky_H]

I've been seeing this for years, even before the Model 3, that some people get really unnecessarily obsessed with trying to get full regen capability. They talk about "having a consistent driving experience". Well...it is a consistent driving experience. You can count on it, throughout the Winter, that you will consistently have partially limited regen every single day until Spring. It's not a big deal.

 

[Dana1]

I've been seeing this for years, even before the Model 3, that some people get really unnecessarily obsessed with trying to get full regen capability. They talk about "having a consistent driving experience". Well...it is a consistent driving experience. You can count on it, throughout the Winter, that you will consistently have partially limited regen every single day until Spring. It's not a big deal.

I was super excited, here in south Texas, to finally get the oft mentioned Limited Regen message one morning. Until I realized that meant it was freakishly cold and I had to wear real shoes and a coat. I’m fine with consistently warm...kudos to you northern climate folks.

 

[SSedan]

HCWC at maximum rate for your car is good at improving regen.

Car will warm the battery enough to charge and then charging at a higher rate will provide additional warming.

Ambient temperature is not pack temp either. If if goes to 40f overnight but warms to 55f by the time you leave for work, it isn't 55f temps causing regen limiting it is the pack is still cold from 40f.

 

[ConcordeSST]

Charging the battery at 16 amps (4 kW) won't generate enough heat to completely restore regen.

I was wondering about that. I can only charge at 24 amps on my NEMA 14-30 and have never been able to experience the full regen others report when charging right before leaving. I park in a garage that tends to be between 40-50F.

 

[Big Earl]

I was wondering about that. I can only charge at 24 amps on my NEMA 14-30 and have never been able to experience the full regen others report when charging right before leaving. I park in a garage that tends to be between 40-50F.

I've never gotten full regen when cold (below freezing), even after charging at 48 amps for several hours. The waste heat from charging - at any level - just isn't enough to warm the pack up to that level.