Question about kW vs km per hour?

[tom_1983]

Hi everyone,

So after I got my Model 3 I ran the battery down to maybe 50% to try a Supercharger so I drove to the one in Pickering near Toronto since it said it supports 120kW. There was a Model X there only, but both stalls I tried only charged at around 35-45kW until around 70% when I left since I was just testing it out. When it was at 48kW it showed 348 km/hr. When it started out it was at 62 or so for a few minutes but was showing 295km/hr or so.

Yesterday I went on a trip to visit family, so my car was at 25% or so battery today, so I went to the Bay Street location downtown Toronto in the Eaton Centre to try charging there. This location says max 70kW for the speed, which is the reason I went to Pickering the first time. Anyway, I plugged in and I was getting around 67-68kW, however the charging speed was 480km/hr. I was the only car here and had the whole place to myself the entire time. I went into the mall to shop a bit and got the notification 35 or so minutes later saying Supercharging is complete. My battery limit is set to 85%.

Not entirely sure how to phrase my actual question here but I guess I thought 480km/hr seemed really fast, like what I'd expect charging at 120kW, but I was only at 65 or so. What kind of km/hr speed would I expect if I was actually charging at 120kW?

I know it depends on the battery state of charge but I'm just meaning more in general. Does the kW directly relate to km/hr or are they separate? 480km/hr seemed really fast at 65kW so wondering if that doubles if I actually got 120kW or how that works. I just don't recall ever seeing anyone on here or PlugShare ever mention charging above 500km/hr, always seems to be in the 400 range.

 

[TexasEV]

Don’t try to think in km/hr. It’s the average rate over your supercharging session, not what’s happening at that moment. The kW shown is the power being delivered at that instant. There is no direct correlation between the two values shown as they’re reporting two different things.

 

[Kermee]

@tom_1983, I second what @TexasEV stated. While it's easier to mentally process the Supercharging speed in km/hr (or mi/hr), it's an instantaneous reading at that point in time and isn't actually a good gauge. Knowing the kW and kWh delivered are more important as you will most likely discover down the road.

But if it tickles your fancy, this is what 115 kW looks like in km/hr:

P.S. Waiting for people to give me crap for leaving the temperatures in Fahrenheit instead of Celsius...

 

[tom_1983]

@tom_1983, I second what @TexasEV stated. While it's easier to mentally process the Supercharging speed in km/hr (or mi/hr), it's an instantaneous reading at that point in time and isn't actually a good gauge. Knowing the kW and kWh delivered are more important as you will most likely discover down the road.

But if it tickles your fancy, this is what 115 kW looks like in km/hr:

P.S. Waiting for people to give me crap for leaving the temperatures in Fahrenheit instead of Celsius...

Haha thanks guys! Honestly I wish you could split it, as I prefer Fahrenheit for indoor temperature but Celsius for outdoor lol. All my thermostats in the house and condo are in Farenheit but I prefer Celsius when talking about the temperature outside. Wish the M3 could show me outdoor temperature in C but inside in F, but then again my phone which is always on the dock does show it in C so now you got me thinking... Think I'm gonna switch it now! And thanks for the photo btw!

 

[tom_1983]

Actually I do have one other question I might as well try asking here. On a Supercharger that only runs at 70kW is it possible to manually limit the charging speed to keep it under 60kW? Since it's 20 cents a minute under 60 and 40 over, it's kind of a waste getting 62-65 and paying basically double when it's pretty much on the verge lol.

 

[Kermee]

Actually I do have one other question I might as well try asking here. On a Supercharger that only runs at 70kW is it possible to manually limit the charging speed to keep it under 60kW? Since it's 20 cents a minute under 60 and 40 over, it's kind of a waste getting 62-65 and paying basically double when it's pretty much on the verge lol.

Unfortunately, there isn't a way to limit the kW rate during Supercharging (DC) like you're able to with the onboard (AC) charger. I'd wish Tesla would just charge one single rate ($0.20/min) at the 72kW Urban Chargers, but not sure if that'll ever happen, or if the Provinces would ever "exempt" Tesla from being able to charge kW/hr (i.e. selling electricity vs. "parking fees").

 

[tom_1983]

Unfortunately, there isn't a way to limit the kW rate during Supercharging (DC) like you're able to with the onboard (AC) charger. I'd wish Tesla would just charge one single rate ($0.20/min) at the 72kW Urban Chargers, but not sure if that'll ever happen, or if the Provinces would ever "exempt" Tesla from being able to charge kW/hr (i.e. selling electricity vs. "parking fees").

No worries just thought I'd check! Right now I charge from the normal wall plug at 7kW which is rough, as I own the wall charger but when we got our delivery date on the M3 we decided screw it, let's sell the house downtown and move a bit outside of the city so we can do the solar roof and get off the grid eventually! So I have it in the box but wasn't going to pay to have it professionally installed if I'm moving in a month or two. I have a condo downtown but no charging there, but the Bay Street location is 1 block away. Just a bit of a pain since it's $4 for 20 minutes parking plus the Supercharger, but weekends aren't too bad as it's $10 for 3 hours. Either way it still beats the hell out of paying for gas, even with the parking fee!

 

[Rocky_H]

Unfortunately, there isn't a way to limit the kW rate during Supercharging

"Fortunately, there isn't a way to limit the kW rate during Supercharging"

There--fixed that for ya. Superchargers are to fill up fast and move out of the way, not to hang around charging slowly.

 

[tom_1983]

"Fortunately, there isn't a way to limit the kW rate during Supercharging"

There--fixed that for ya. Superchargers are to fill up fast and move out of the way, not to hang around charging slowly.

It's already charging slowly, we are talking about urban chargers that only do 70kW. 40 minutes at 62kW vs limiting it to 58kW to stay under 60 isn't really going to slow things down. Perhaps the urban chargers should cost the 20 cent per minute rate all the time vs the 40 otherwise there's not much benefit to using them especially when you're paying $10 in parking for that 40 minutes as well.

 

[TexasEV]

It's already charging slowly, we are talking about urban chargers that only do 70kW. 40 minutes at 62kW vs limiting it to 58kW to stay under 60 isn't really going to slow things down. Perhaps the urban chargers should cost the 20 cent per minute rate all the time vs the 40 otherwise there's not much benefit to using them especially when you're paying $10 in parking for that 40 minutes as well.

Not much benefit in using them? How else are you going to charge your car most of the way in 40 minutes? If it's not worth the parking fee to you and you can't charge at home, then plug it into a J1772 charging station overnight somewhere.

 

[Kermee]

"Fortunately, there isn't a way to limit the kW rate during Supercharging"

There--fixed that for ya. Superchargers are to fill up fast and move out of the way, not to hang around charging slowly.

I definitely agree with you. Superchargers are to fill up fast and move out of the way.

Crux of the issue in Canada is pricing is done at two rates, Tier 1 ($0.20 CAD/min at or below 60kW) and Tier 2 ($0.40 CAD/min above 60kW) no matter if it's a "regular" 120kW Supercharger or a 72kW "Urban" Supercharger. I do understand the argument for and against leaving the 60kW threshold on a 72kW "Urban" Supercharger. Maybe "limiting" the charge rate at Superchargers isn't the best solution. It's just a typical non-Performance Model 3 consumer has to pay for Supercharging, charging near max at 72kW vs. 120kW, you don't nearly get the same value price per kWh. But of course, it's up to the consumer to determine if the price-premium charging at an Urban Supercharger in Canada makes sense or not.

Maybe a better solution would be if it's just a flat per minute "parking" fee for an Urban Supercharger (maybe $0.30/min, average of the two Tier rates). I think the current structure for "idle" fees are incentive enough for people to move their vehicles after they are done charging.

 

[tom_1983]

Not much benefit in using them? How else are you going to charge your car most of the way in 40 minutes? If it's not worth the parking fee to you and you can't charge at home, then plug it into a J1772 charging station overnight somewhere.

Is there any particular reason people on this forum get all bent out of shape and have to change every single topic into something else? I simply asked a question if it's possible to limit the speed you charge at to keep it under 60kW since you're paying 2x as much for a whole 2-5kW more. I already got the answer, but never fails someone like yourself has to come in here after the question has already been answered and trying to make himself look all smart while adding absolutely nothing to the conversation.

You're not even from Canada, so maybe you should get a clue before opening your mouth and trying to sound smart. Obviously others feel the same way, considering every single time I go there (as I pass it almost daily going to the mall) the chargers are completely empty without a single vehicle charging there.