Why Is home charging slower than Tesla?

[Nimar]

Anyone understand why home charging is so much slower than a Tesla? It’s the same 11.5 kW charging, but R1S gets 25 miles and the model Y gets 44 miles off an hour of charging.
Sigh…..

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[SoCal Rob]

I think the charging rate in miles per hour is lower because that estimate incorporates the historic energy use of the vehicle. If you look at just kilowatts per hour you’ll probably see a different result since that isn’t factoring vehicle efficiency, weather conditions, or driving style.

 

[Nimar]

Oh. I was just referring to the max charging rates from the vehicle specs online.

 

[SoCal Rob]

Oh. I was just referring to the max charging rates from the vehicle specs online.

In that case it comes down to vehicle efficiency and battery size. Using miles per hour instead of unit of energy per hour is always going to take into account how many miles the vehicle can go on a unit of energy.

Think of the ICE comparison: we are told how many gallons of fuel we’ve added and we could time how long it takes. If you had a slow gas pump that only delivered 1 gallon of fuel per hour and you took an hour to put 1 gallon of gas into an economy car that gets 45mpg and the same amount into a large SUV that gets 20 miles per gallon you would have added 45 miles of range per hour to the economy car and 20 miles of range per hour to the large SUV even though it was the same amount of gas. If you go to a gas pump that delivers 2 gallons per hour the same economy car gets 90 miles of range added per hour and the same SUV gets 40 miles of range added per hour.

Hopefully that helps explain things.

 

[CharonPDX]

When you pour 3 gallons of gas per minute into a Ford Escape Hybrid versus a Ford Bronco, why does the Bronco only add 54 miles of range per minute while the Escape adds 132 miles!?

Because one vehicle is more efficient than the other. Adding the same amount of energy to the system, the more efficient vehicle will add more range per minute/hour.

Rivian R1S is rated at 69 MPGe (uses 49 kWh to drive 100 miles) while Model Y Long Range is rated at 122 MPGe (uses 28 kW to drive 100 miles.)

Model Y is one of the most efficient vehicles available for purchase in the US today. (The even smaller/lighter/more-aerodynamic Model 3 Long Range is tops at 132 MPGe with the Lucid Air right behind.) R1S is the second-least efficient EV - only the Hummer EV is less efficient at 47 MPGe.

 

[zipzag]

Another short answer is Model Y needs 81 kWh to go 300 miles. Rivian needs 135kWh to go 300 miles.

But for most people charging at home the Rivian operating cost still isn't bad at all.

 

[joelster]

Charon said it. The charging rate is the same between a Rivian and a Tesla: 11.5Kw. The Tesla has better range per kilowatt hour so the same number of kWh translates to different miles per hour charged.

 

[rodhx]

Charon said it. The charging rate is the same between a Rivian and a Tesla: 11.5Kw. The Tesla has better range per kilowatt hour so the same number of kWh translates to different miles per hour charged.

Yep, they charge at the same speed. The Rivian isn’t slower. Like any truck it gets worse ”gas mileage”.

 

[JGard18]

I'm a little amused by this thread. OP states both charge at 11.5kW, yet asks why one charges "slower". Sorry, mate, they charge at exactly the same speed, as you've already identified.

 

[Dark-Fx]

Why are all of Tesla's cars ugly egg shapes and the R1S is a beautiful box?

 

[rraj2k81]

@Nimar - The miles added is an estimation based on a multitude of factors including driving efficiency and battery capacity. kW should be the only number you should be looking at for charging rate. And since you mentioned both charge at 11kW then they are both charging at the same rate.

Your Model Y is a smaller/lighter and more efficient vehicle than the R1S, so it is going to have a higher estimation than the R1S

 

[jphillips97]

Anyone understand why home charging is so much slower than a Tesla? It’s the same 11.5 kW charging, but R1S gets 25 miles and the model Y gets 44 miles off an hour of charging.
Sigh…..

Not an electrical engineer are you? As others have said the flow of energy is the same for both, it just takes more energy to take the Rivian a mile... You are gaining just as much charge even thought not as much range. To gain the same range per unit time, the Rivian would need to charge faster.

 

[crashmtb]

Not an electrical engineer are you? As others have said the flow of energy is the same for both, it just takes more energy to take the Rivian a mile... You are gaining just as much charge even thought not as much range. To gain the same range per unit time, the Rivian would need to charge faster.

It doesn’t take an electrical engineer to know that a glass of water and pail of water filled from the same tap won’t be full at the same time

 

[Nimar]

Thx all. Makes sense to me now.

 

[CommodoreAmiga]

This makes me wonder: Do some people go to Costco and see a Honda Civic next to a Dodge RAM 2500 in the parking lot and think they get the same fuel economy?

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