Super...taper?

[tls]

My 85D has just over 50K miles on it now.
It's seemed for several months as if charge rate has been tapering off sooner and more dramatically.

Car's sitting on the Yonkers supercharger right now. It's about 60F outside, and I rolled in at about 15%. Charging stayed at 75kW ("urban supercharger") through roughly 40% charged, then rapidly began tapering (it was below 70kW by 50% and is at 58kW at 60% now). Louvers and fans seem to be operating correctly and the charge handle's not hot.

Is this normal? Am I just misremembering that the car used to stay at high charge rates for much longer?

 

[ahkahn]

Try a different pedestal. It's unusual that all the pedestals are running at 100% power.

 

[tls]

Try a different pedestal. It's unusual that all the pedestals are running at 100% power.

Nah - note it started at the full 75kW and stayed there for tens of minutes until the rapid taper started.

This is a 20-bay urban supercharger. There were 2 other cars there. It wasn't the infrastructure, and the point of using the slower 75kW uSC was to try to reduce or eliminate the influence of heat. That's why I did the test on the coolest day we've had for months, as well.

So - is this kind of taper normal? I honestly just don't know.

 

[brianman]

Charging stayed at 75kW ("urban supercharger")

I thought urbans maxed out at 72 kW.

 

[TexLaw]

I don't know if that is normal, but I have noticed that tapering begins sooner than it used to. Somewhere around 50% sounds about right, although those kW sound low.

 

[kavyboy]

On my S70, and I think it applies to the 85 as well, I can usually count on Kw = 125 - %SOC +/- 7. (That's nothing official, just something I read here a while back.) Your numbers fit that on the low end. I've also been on the low end of that equation recently, but I figured it was summer heat and the car just getting older.

 

[jplasmd]

I have a four year old P85 with 103,000 miles on it. For the first two years, i charged 98% of the time at home. Since then, and for the last 50,000 miles, most of my charging has been done at Superchargers. Supercharging, for me, has slowed down significantly. Nowadays, as a "rule of thumb", I like/expect to see a charging rate of about 60 kW or more (or roughly half of the max charging rate of 118 kW) when the battery is at 50% state of charge.

FWIW, I can reach 258 rated miles, on a hot day, when the battery is at 100% SOC. I think my rated range was 268 when the car was new (yes, I know, Tesla advertised 265....). I guess the more recent, quicker-to-taper charging algorithms have helped to keep my battery capacity loss at a minimum. .And given me more time for leisure reading when I'm on Tesla road trips..

 

[Kuhz]

That taper doesn’t sound too bad for an urban charger

 

[Shock-On-T]

Tapering definitely seems to be sooner. I think they have more info on keeping our batteries healthy, so have changed the charging behaviour slightly.

 

[Rocky_H]

Charging stayed at 75kW ("urban supercharger") through roughly 40% charged, then rapidly began tapering (it was below 70kW by 50% and is at 58kW at 60% now). Louvers and fans seem to be operating correctly and the charge handle's not hot.

Is this normal? Am I just misremembering that the car used to stay at high charge rates for much longer?

That does not sound slowed down at all. And yes, I think you're misremembering. You have an 85kWh battery, as I do. Those had a pretty predictable tapering rate that was almost linear, as @kavyboy referred to. Let's add up your data points:
69kW + 50% = 119
58kW + 60% = 118
It's not strictly linear all the way through, so that resulting number can be up or down a little, but I've generally seen it around 120 to 125 most of the time. You're just about on that 120 number, so it looks like it's doing exactly as expected.