Noticing that charging over 80% always has limited regen

[mswlogo]

I’ve been charging to mostly 90% once or twice a week. As spring rolled around I didn’t see full Regen coming around like I expected. So I blamed my cool garage. Well now that’s it mid July and near 90F it’s no longer the cool garage.

My battery is simply to full, for full Regen. If I charge to 100% I’ll see Regen gradually return. But not full Regen until around 80%.

Because of this I’m no longer going by the advice that 90% has no detrimental affect. I’m not that concerned about the lost efficiency of a little limited Regen. It’s the fact the battery still thinks it’s to full to accept full Regen makes me a little uneasy.

I think the original target of reserving 90 or 100% for longer trips to be used immediately still holds. And for daily to stick to 80% or below as the UI indicates.

I think the “new” 90% daily is hog wash.

Regardless, my efficiency and range are still awesome. I never have plugged in daily as advised so big deal if I chose 80 or 90. But if I was charging daily I definitely would not do 90% (unless my commute really needed it).

 

[M3BlueGeorgia]

Not my experience at all. We usually charge to 90%, which you should consider.

Battery full regen restriction usually is only in play in the high nineties. Otherwise it is temperature related.

 

[Silicon Desert]

Interesting, I don't see it on my MX as you mentioned. I rarely charge to above 90% because it is just extra time. I usually only charge that high when I am leaving a hotel early in the morning and I scheduled the car to be finished charging to 92% or 95% at that time and plan to leave right away. My regen typically comes back before going below 90%.... sometimes before I even get to the freeway (in comfortable summer temperature)

 

[Runt8]

I’ve charged to 90% every night since I purchased the car, and the only time I get limited regen is when it’s cold out.

 

[Big Dog]

I charge to 90% all the time and have never run into limited regen. I only experience limited regen when I charge to 100% for trips.

 

[mswlogo]

Looks like others are noticing it as well.

In July - regen limited at 90% charge?

Note: I’m not saying there is any limited Regen warning, just a few limited Regen dots.

This is on an AWD, which might possibly have higher Regen capability than a RWD. Not sure if that has ever been confirmed though.

 

[darth_vad3r]

I’ve been charging to mostly 90% once or twice a week. As spring rolled around I didn’t see full Regen coming around like I expected. So I blamed my cool garage. Well now that’s it mid July and near 90F it’s no longer the cool garage.

My battery is simply to full, for full Regen. If I charge to 100% I’ll see Regen gradually return. But not full Regen until around 80%.

Because of this I’m no longer going by the advice that 90% has no detrimental affect. I’m not that concerned about the lost efficiency of a little limited Regen. It’s the fact the battery still thinks it’s to full to accept full Regen makes me a little uneasy.

I think the original target of reserving 90 or 100% for longer trips to be used immediately still holds. And for daily to stick to 80% or below as the UI indicates.

I think the “new” 90% daily is hog wash.

Regardless, my efficiency and range are still awesome. I never have plugged in daily as advised so big deal if I chose 80 or 90. But if I was charging daily I definitely would not do 90% (unless my commute really needed it).

Not sure the outside air temp is hot enough to help it get up to an optimal operating temp of maybe as high as 104 (86-104F is 30-40C I think it's looking to be in that range). If it is any cooler at all overnight the battery takes a while to actually warm up and will not actually be at 90F when you leave your house if it is 90F outside. It could still be a lot cooler internally.

How long do you drive before you see full regen available?

I need ~20+ minutes of driving on the highway on my commute before I see the regen dots disappear and this is in 23-27C temperatures (73-81F)

 

[ewoodrick]

So what's the problem with limited regen? If you are concerned that much about efficiency, then I'm assuming that you aren't driving over 55 mph.

 

[darth_vad3r]

So what's the problem with limited regen? If you are concerned that much about efficiency, then I'm assuming that you aren't driving over 55 mph.

No, it didn't sound like they were concerned with efficiency, but health of the battery:

Because of this I’m no longer going by the advice that 90% has no detrimental affect. I’m not that concerned about the lost efficiency of a little limited Regen. It’s the fact the battery still thinks it’s to full to accept full Regen makes me a little uneasy.

[...]

Regardless, my efficiency and range are still awesome.

I think the original target of reserving 90 or 100% for longer trips to be used immediately still holds. And for daily to stick to 80% or below as the UI indicates.

I think the “new” 90% daily is hog wash.

When you say "new", what are you considering "old"? ... didn't the prior charging screen (for Roadster, S, X, not the 3) have separate "range" mode? I believe the non-range mode (normal mode?) would charge to higher than 90% actually ... 92 or 93%?

 

[mswlogo]

Not sure the outside air temp is hot enough to help it get up to an optimal operating temp of maybe as high as 104 (86-104F is 30-40C I think it's looking to be in that range). If it is any cooler at all overnight the battery takes a while to actually warm up and will not actually be at 90F when you leave your house if it is 90F outside. It could still be a lot cooler internally.

How long do you drive before you see full regen available?

I need ~20+ minutes of driving on the highway on my commute before I see the regen dots disappear and this is in 23-27C temperatures (73-81F)

Depends on how hard I drive it to get no Regen limit. If 86F - 104F is ideal that probably explains it. Garage is probably under 80F. My commute is only 5 miles. No highway. So not much warming up. Then 5 miles back. So my daily commute never warms it up. If I hoped on highway it would probably be full in 10 minutes or so.

Thanks

 

[darth_vad3r]

Depends on how hard I drive it to get no Regen limit. If 86F - 104F is ideal that probably explains it. Garage is probably under 80F. My commute is only 5 miles. No highway. So not much warming up. Then 5 miles back. So my daily commute never warms it up. If I hoped on highway it would probably be full in 10 minutes or so.

Thanks

If you schedule charging at home to end before you leave in the morning you might get more regen from the battery being warm from charging? Then again, some other thread said it's better to charge your battery right after you use it to reduce degradation

 

[mswlogo]

No, it didn't sound like they were concerned with efficiency, but health of the battery:

When you say "new", what are you considering "old"? ... didn't the prior charging screen (for Roadster, S, X, not the 3) have separate "range" mode? I believe the non-range mode (normal mode?) would charge to higher than 90% actually ... 92 or 93%?

Some time this winter a prominent Tesla owner (Living with Tesla or Something) saw her full charge tank and Tesla advises her to charge 90% instead of under 80% ( she was extra conservative and was using 70%). She posted a Video on it. Then about 40 threads were created saying Tesla/Elon now says 90% daily is fine. Where before 90% or higher was recommended for immediate use and longer trips.

I call this the “new” recommendation. Don’t recall if there was also an Elon tweet kn it. Nothing in documentation or UI changed as far as I know. But the UI hints 90% and up is for “trips”. This Regen thing to me is just a hint that battery is still to full at 90% to get full Regen. Even at modest temps.

I’m not familiar with S/X range mode.

But the UI is a little vague here at 90% mark.

Longevity wise we won’t know for 5 years. But I’m gonna go back to 80%. Especially with my usage pattern.

 

[mswlogo]

If you schedule charging at home to end before you leave in the morning you might get more regen from the battery being warm from charging? Then again, some other thread said it's better to charge your battery right after you use it to reduce degradation

Charging on my level 2 does squat for warming. I charged to 90% for 4 hours (24 Amps 240V), hot day and still had Regen dots. It feels more like the battery is too full than too cool. But warming it by driving hard will get full Regen fairly quickly. I generally drive the car lightly to work.

 

[WilliamG]

90% = 7-8 regen dots for me, period. Once it drops to around 80% I get full regen. Earlier today I drove the car down to 78%. It's been left untouched all afternoon and evening. Just went out to the car, still at 78%, and I have full regen straight away.

I think I'll start charging to 85% and see if that helps. I usually charge to 90%.

 

[scubastevo80]

90% = 7-8 regen dots for me, period. Once it drops to around 80% I get full regen. Earlier today I drove the car down to 78%. It's been left untouched all afternoon and evening. Just went out to the car, still at 78%, and I have full regen straight away.

I think I'll start charging to 85% and see if that helps. I usually charge to 90%.

I charge to 85% and have 4 regen dots. Like you, I have full regen as it drops closer to 8%. I am fine with the slighltly limited regen as it is unnoticable to me in daily driving.

 

[Rocky_H]

This is kind of a "duh" thing. Think about the charge tapering curve when using a Supercharger. It is exactly the same effect. You see the charging kW power coming down and down to where it's getting toward 40kW and 30kW and 20kW when you are getting into that 80% to 90% area. Well, full regen power from the motor is about 60kW, so yes, of course it is going to be slightly limited below that when your battery is about 80-90%. It's not really different whether that's coming externally from a plug or internally from regen.

Those who say they don't have any limits in that area aren't quite understanding the issue. You are thinking of the extremely limited regen like from winter that you can really feel when driving, but regardless of time of year or temperature, it is going to be a little bit limited if you're at 90% full no matter what. You probably can't feel that very much, but it would be slightly less than full regen.

 

[Runt8]

This is kind of a "duh" thing. Think about the charge tapering curve when using a Supercharger. It is exactly the same effect. You see the charging kW power coming down and down to where it's getting toward 40kW and 30kW and 20kW when you are getting into that 80% to 90% area. Well, full regen power from the motor is about 60kW, so yes, of course it is going to be slightly limited below that when your battery is about 80-90%. It's not really different whether that's coming externally from a plug or internally from regen.

Those who say they don't have any limits in that area aren't quite understanding the issue. You are thinking of the extremely limited regen like from winter that you can really feel when driving, but regardless of time of year or temperature, it is going to be a little bit limited if you're at 90% full no matter what. You probably can't feel that very much, but it would be slightly less than full regen.

I'm saying that when I leave in the morning with 90% charge I don't have any dots on the left. If there's any regen limiting actually occurring I can't say.

 

[Rocky_H]

I'm saying that when I leave in the morning with 90% charge I don't have any dots on the left. If there's any regen limiting actually occurring I can't say.

Right. There is sometimes some slight limiting that is going on that they do not want to show to people by putting things on the display. They sure as hell don't want to fill up all of their service centers by recommending to people to use up to a 90% charge limit and then constantly having thousands of people making service appointments every week for their "broken" cars because they see these limitations and can't figure out how to make them go away. It's just a very slight limiting of regen force that will go away pretty quickly, and most people won't even notice it much.

Having the extra range is good, but not being able to dump 60kW of power into it is what it takes to enable that, and they don't want it to feel like there's something wrong with that being the nature of how that works.

 

[Runt8]

Right. There is sometimes some slight limiting that is going on that they do not want to show to people by putting things on the display. They sure as hell don't want to fill up all of their service centers by recommending to people to use up to a 90% charge limit and then constantly having thousands of people making service appointments every week for their "broken" cars because they see these limitations and can't figure out how to make them go away. It's just a very slight limiting of regen force that will go away pretty quickly, and most people won't even notice it much.

Having the extra range is good, but not being able to dump 60kW of power into it is what it takes to enable that, and they don't want it to feel like there's something wrong with that being the nature of how that works.

But the op is seeing the limited regen dots on his display.

 

[SSonnentag]

I can confirm limited regen even below 80%, even when it's hot outside (95+ degrees). BUT ... the limit only occurs if you're regenning (is that a word?) a lot, such as coming down a long steep hill.

In my case I leave home with 80%, then arrive at the top of a 6-mile 10% grade with around 77%. I'll start the hill getting full regen, but then about half way down it gets limited to around 40 kW. I arrive at the bottom of the grade with around 78% battery.