Pairing not quite what I'd been led to believe

[adspguy]

I was on a roadtrip and happened to capture my supercharging session with tm-spy. I connected my dec-2106 90D to an unpaired station (1b) at the Framingham MA superchargers. I had been driving for about 1 hour after my car sat in the 30 degree cold for about for about 8 hours. The battery temperature had reached about 66 degrees by the time I reached the station with about 10% left in the battery. The first picture I've attached is the entire session. As you can see, it starts off ramping slowly over about 7 minutes up to about 120kW. It slowly settled in to 112kW and stayed there for maybe 5 minutes and then started a slow taper. The second picture is blown up to show the step-wise change in charging which occurred later in the session. The first of two steps happened immediately when a model 3 connected to the paired station (1a) where my charging dropped from the 112kW to about 84kW. A couple minutes later it again took a step-wise change down to about 69kW. It seems that the "I was there first, give me all the charge I want" sharing method is not in force now.

 

[ilyak]

It seems that the "I was there first, give me all the charge I want" sharing method is not in force now. View attachment 486501 View attachment 486502

It's definitely not in place. I've dropped from 140+ kW to ~60kW when a car connected to the paired charger many times now. It doesn't matter what SoC I'm at either (one theory I've read is that the lower SoC car gets the priority) - I've seen the same drop when I was at 2%.

 

[boaterva]

Interesting. Are we back to ‘you should never park at an occupied pair’ (as the second car)? Jeez....

 

[kavyboy]

Interesting. There have been quite a few posters saying that their charge rate dropped when the other pair became used, but they were always met with "Pairing doesn't work that way" comments. It looks like maybe the power is indeed split (i.e., the first charger's power is reduced) when a second charge connects on the pair.

 

[Missile Toad]

Maybe I'm going to get a vinyl glove, and start putting it over the charger handle in my neighboring stall... just to fend of the newbies.

 

[ewoodrick]

Are we really sure that the step down isn't the normal one that occurs? And happens to be consequential?
Did you happen to look at the charging rate of the car that parked at the paired spot?

 

[adspguy]

Didn’t see the rate of the neighboring car, they walked away quickly. The rate definitely stepped right when they plugged in. I’ve seen the slow ramp down continue at the same slope that was happening before they plugged in. At that point more than half the stations were used so they had to pair up anyway.

 

[rrolsbe]

Didn’t see the rate of the neighboring car, they walked away quickly. The rate definitely stepped right when they plugged in. I’ve seen the slow ramp down continue at the same slope that was happening before they plugged in. At that point more than half the stations were used so they had to pair up anyway.

The sharing algorithm has definitely changed from first car has priority. I was charging at around 104KW rate and the car was less than 5 minutes from having enough to continue the trip. After a Model X plugged in, my rate dropped to around 70KW and the 5 minutes went to 10 minutes (this was expected for a 50/50 share); however, after the X ramped up a few seconds later my rate dropped to 35KW and the time went to 15 minutes. Do you suppose the expensive Model X has priority over my less expensive Model 3? NO couldn't be! If my rate would have stayed at 104KW and the Model X got the leftovers, I would have unplugged and departed in less than 5 minutes. What I did was unplug and charge down the road 60 miles at another Superchager, after dropping off wife and dogs at the motel.