Very slow charge rate from 85-90% on a level 2 charger

[dk10438]

Hi
I'm wondering if this is normal. I know that charging to 90% or 100% takes considerably longer on a SC. My question is NOT regarding a SC, it's about level 2 charging.

At work I have access to a level 2 clipper creek charger which gives me something like 18 miles per hour. I'm wanted to get the car to a higher SOC to test out 0-60 pulls. I set the charge level to 95% which was supposed to take about 4.5 hours or so. The car started charging at about 18 miles per hour but when I came back 4 hours later, i was at 87% and the charge rate was down to 3 miles per hour. Is this normal behavior? I haven't really noticed this on my car since I typically charge to 70% and it's in the middle of the night anyway. The few times that I've charged to 90 percent, I haven't noticed the charge rate go down that much.

Does the decrease charge rate diminish that much getting to 90%? And is it related to the amps available? ie I charge at 60A and I haven't seen the charge rate decline that much even to 90 or 95% so I'm wondering if this is because I was using a public level 2 charger that only had 30A.

Thanks

 

[DOCAL]

That doesn't sound normal, I see full speed on a 30A charger up to high 90s.

 

[joninurmimetsa]

Second this. I usually see taper on our home 32A home charger maybe only after 93-95%. Up to that point it's full 32A and even then at 96-97% it's still +25A.
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JN

 

[joninurmimetsa]

Please see attached picture. Taper starts from 96%.
This is 2015 Model S P85D.

(In the picture amperage jumps back up because I turn on heating, but charging rate drops.)


-
JN

 

[ucmndd]

Provide the observed amps and volts for real troubleshooting. Miles per hour is useless.

 

[dk10438]

yeah
wonder if it's an issue with the car or charge station....
Since there's multiple charge stations I'm wondering if there was any voltage sag causing a change in current...

 

[dk10438]

Must have been the charging system at the hospital...

Charged for 90% at home and there was no taper.

 

[AmpedRealtor]

In my 2013 P85, the taper adjusts itself downward the longer I've been charging. If I start charging from 30%, by the time I hit 85% the car has already tapered the charge from 80A down to 72A while using my wall charger. If I start charging from, say, 70% then I'm still at 80A when I hit 90%. Since #chargegate, fans don't kick on like they used to. Instead of cooling spooling up to keep charge rate higher, the charge rate drops without ramping up cooling to any significant degree. It's almost as if Tesla decided that cooling matters less than the charge rate.

Same thing at the Supercharger. No fans. The highest charge rate I've seen was 56 kW when charging from 40% SOC. All cooling systems quiet. The behavior is very strange. No warnings. HVAC works fine.

 

[Lasttoy]

Amped, I had a slow rate, they determined my #2 cooling pump was bad. I changed it (took 5 minutes), fixed the problem. I also had the orange danger line on screen , that went away after new pump .