Charging Priorities

[Ronald Ulrich]

I was told in Fremont that charging, at least in Fremont, there is a priority in charging. New arrivals will be slower charging than vehicles there before you. It seems to be working when the Superchargers are all occupied.

 

[Derek Kessler]

They're talking about paired Superchargers on a single transformer, such as chargers 2A and 2B. If somebody is already charging in 2A and a car joins them in 2B, then 2A will continue to charge at the car's full speed and 2B will get what the transformer can offer. As 2A tapers, 2B will pick up the slack. When 2A is done, 2B will get full juice.

 

[Rocky_H]

That is the consistent naming rule you can look for at all of the Superchargers. Each number corresponds to one stack of the charging hardware, and the A and B sides are sharing the power of it. So you should try to look for a number where the A and B are both open and use one of those, so you're not on reduced power sharing with another car.

 

[roscoe]

I'm in favor of not taking away power from 2A to accommodate 2B, until capacity has been met.

 

[TexasEV]

There is no change. Superchargers have been paired like this since day 1.

 

[Rocky_H]

I'm in favor of not taking away power from 2A to accommodate 2B, until capacity has been met.

It is almost that way. First car does get priority and will get more of the charging power, all else being equal. But, let's say the first car just plugged in and is very low on charge state. They would get something near 115kW of the 120kW from the charging equipment. Second car would only be left with 5kW. They don't let that happen. Secondary car gets 30kW minimum, so first car would start at 90kW. That's a little lowered, but it would have tapered from 115 down to 90 within the first 5-10 minutes or so anyway, so it's not that big a difference.

 

[Hash Browns]

Check out the Supercharging FAQ page here: Supercharging

It answers this question directly, and has lots of other helpful info.

"How can I maximize power and reduce charge time at a Supercharger?
Each charge post is labeled with a number and letter, either A or B (e.g. 1A, 1B, 2A, 2B). When possible, select a charge post with a unique number that is not currently connected to a vehicle. When a unique number isn’t available, the Supercharger cabinet has technology to share available power between charge posts A and B. To maximize power, park at a Supercharger shared with a car that is nearly done charging. For Superchargers in urban areas, there is no need to consider these suggestions, as those sites do not share available power; each car has dedicated power available."

 

[Derek Kessler]

It is almost that way. First car does get priority and will get more of the charging power, all else being equal. But, let's say the first car just plugged in and is very low on charge state. They would get something near 115kW of the 120kW from the charging equipment. Second car would only be left with 5kW. They don't let that happen. Secondary car gets 30kW minimum, so first car would start at 90kW. That's a little lowered, but it would have tapered from 115 down to 90 within the first 5-10 minutes or so anyway, so it's not that big a difference.

A Supercharger is rated at a maximum of 120kW, but the transformer cabinets they're sharing are typically 145kW, so there's usually a fair amount of excess capacity available even when Car 1 is charging at the full rate (which, as you note, will soon decline as the charge level increases).

 

[Rocky_H]

A Supercharger is rated at a maximum of 120kW, but the transformer cabinets they're sharing are typically 145kW, so there's usually a fair amount of excess capacity available even when Car 1 is charging at the full rate (which, as you note, will soon decline as the charge level increases).

I think you're mixing some things up. You're talking about "a Supercharger" as being 120kW, and then "the transformer" as being 145kW. Those terms aren't being used right. The transformer is the really large thing that feeds energy to the whole site, so it's a lot more than either 120 or 145kW. What you are probably thinking of is how they have been coming out with some higher power Superchargers along the years. The first old ones were 90kW. Then later, they came out with the 120kW, and even more recently the 145, etc. But when they came out with the 145kW version, they didn't go through and upgrade all of the existing ones, so most of the ones in North America that were sites from a year or two ago are still mostly 120kW versions, not 145kW like the newer ones.