Electric vs Gas Cost

Listen if it really is 33 years of use then I've just found the car to last me the rest of my life or maybe I'll need 2 but still. I would love a car that lasts 33 years!

And yes I'm a slow adopter of new stuff, I picked the old cast iron 2.7 just because I didn't know how reliable the 3.5 was.

 

Well here's something new, some actual EV vs Gas costs. When I installed my EV charger I put in a separate meter so I could see exactly how many KW/h the car was using. Today's errands required 42 miles of mixed freeway and city driving. To recharge my Tesla Model Y after that took 1.5 hours at 240 V 32 amps and 10.9 KW/h of electricity. I pay 11 cents/KW so that trip cost $1.20 or 3 cents/mile.

For comparison locally gas is selling for 4.25/gallon

Tesla Model Y long range 3 cents/mile
vs different gas mpg
10 mpg = 43 cents/mile
20 mpg = 21 cents/mile
30 mpg = 14 cents/mile
40 mpg = 11 cents/mile
50 mpg = 9 cents/mile

 

If you used Tesla’s wall connector, the Wall Monitor app can give you lots of good data without needing a separate meter. I use it.

 

I just have the mobile adaptor. When I put in the charging line I didn't know much other than gee for $50 I can add this meter. Now I use it to play nerd games like to charge from 10% to 70% on 240 V 32 Amps takes 49 KWh. But to charge it the same amount on 120 V 12 amps takes 54.5 KWh. Low and slow might win the battery longevity race, but it takes 41 hours. Yeah, it's 240V all the way for me.

 

I believe that is due to overhead in heating the battery for charging. With 120v you end up spending a higher percentage of the input power heating the battery making it less efficient.

 

Yeh slower is better for the batteries. Wonder if Solid State Batts will even need a slow charge they'd charge so fast. Level 1 could be today level 2 for the new Toyota batts.

 

120v or 240v is irrelevant in charge speed for battery longevity. 220 is around 8kw/hr when a "slow" fast charger (150kw) is near 20 times that.

Lithium charging is represented in "C" where 1C is a FULL charge in one hour, 2C is a full charge in half an hour, etc. Most lithium technology is comfortable at less than 1C, a 220v standard outlet is around 0.125C and a 120v around 0.06C on a SMALL tesla battery, both WELL into the comfort range for lithium batteries. Even a 100amp 220v circuit won't shorten battery life by any measurable amount.

 

6I was implying that I didn't mention, like Toyotas fast charge solid state should charge faster at home than on DC fast charge.

 

I had only heard of toyotas solid state battery but I had not looked into it.

Folks are going to need some electrical upgrades, my 200 Amp panel would only do 35kw. I wonder what the maximum current the connection from the utilit can handle.

 

Whoa I looked up some info on Toyota's prototype ss battery and they say 740 miles range 10 min charge that would mean at least 150amp draw or more (someone with a better handle I=V/R can correct me). If they succeed that'd be an awesome battery and honestly I wouldn't need that mega range. 400 miles is more than enough.

However on a home charger I'm sure 200 amps is more than enough as we don't need fast chargers at home if we plug in overnight. Tesla chargers are usually on a 60 or 40 amp breaker.

 

On a 220 home circuit 745 miles in 10 minutes would be about a 5,000 Amp draw. That is megawatt charging, or 1000kw, a normal 60 Amp circuit (48 Amp continious) is around 10kw.

(Rough numbers)

This sounds impressive but really isn't far off what tesla is doing today for the semi and rumored to be in the Cybertruck. There is someone else doing this, or about to do this, but I cannot remember who

 

That's for DC fast charger stations. Home chargers cant do DC fast charge. Typically 40 amp or so max. Level 2 is the most at home.

 

I know this is a wall of text so here's the TLDR at the top. 1 - Toyota's ss battery is hype to keep people on the side lines rather than buying an EV. 2 - 10 minute charging such a battery can only happen at a Tesla semi sized charging station. 3 -There is no way it can ever happen at home.

Toyota's ss battery was announced nearly 13 years ago, much like fusion power it's only 10 years away. Honestly it seems more like a tactic to keep people on the EV side lines rather than an actual product that will be delivered.

edit - holy hype train hanna! Toyota just announced a 932 mile battery that will charge in only 10 minutes!! /s However, they make no mention of the size, weight, or capacity of this modern marvel. I call bullshit.

Lets do some math here and since Toyota is short on details I'm going to use the 400 mile Tesla Model S battery at 100 kWh. To get in the ball park I'm going to double it to 200 kWh for 800 miles of range. What would it take to charge that much battery in 10 minutes. Here's the formula for those that want to play along at home: Time in hours = Battery kWh / (Volts * Amps /1000) This calculation does not care what battery chemistry is used it simply calculates the flow of electrons. A similar gasoline calculation would be gallons per hour. If you have a 10 gallon gas tank and a 5 gallon per hour pump it will take 2 hours to fill the tank. It doesn't matter that the gas tank could be filled in 1 minute the pump is the limitation.

For reasons, 48 amps at 240 volts is the maximum power (pump speed) available in the average home. So, plugging that into the formula above the mythical Toyota battery would, in a perfect world, take 17.4 hours to charge from 0 to 100 percent. SS or regular lithium ion battery doesn't matter, it would take 17.4 hours to charge.

For sake of completeness what would it take to home charge in 10 minutes? TLDR it is not possible. The maximum voltage in most neighborhoods is 7,200 volts. In a prior life I worked on power lines and that voltage is crazy. I've seen green, growing trees on fire where they were touching the primary (7,200 V) lines. But, what if for some reason we were to install a primary line into a house? ( and never going to happen) It could charge the battery in 35 minutes at 200 amps.

OK what does it take to supercharge in 10 minutes? First, the NACS connector isn't going to be able to handle the load, so that will require a new plug. Tesla semi maybe? Yeah, let's go with that. 1,250 Volts at 3000 Amps gets the job done in 3 minutes.

 

Just pointing out that it is unfeasible with the architecture used for residential electricity

 

Yes it’s a definite hype/publicity move to advertise 10 minute charging but that’s basically how every manufacturer advertises their vehicles. No one advertises based off a 40amp home charger, it’s always based off the fastest available DCFC the battery is designed to handle.

 

Agreed, but I've seen some folks thinking they could charge that fast at home. Also, Toyota makes no mention of how physically big their mythical battery is. What is its energy density? How do they calculate that 932 mile range. How many kWh? Don't get me wrong, SS batteries would be awesome for reasons other than charging speed. But, here we are 13 years later and still no SS batteries. I know when I'm being strung along and the poster child for the "I don't get EV's - Toyota" is stringing people along.

 

A lot closer to 12 a day.

 

I think people prefer driving trucks and SUVs and V8s at that.


https://www.instituteforenergyresea...-risks-rise-as-electric-vehicles-proliferate/

 

10k miles a year @17mpg = 588 gallons / 365days is 1.6 gallons per day @ 3.50 a gallon is $5.64 dollars a day spent in fuel. What does it cost to charge your EV? subtract that for the differential per day. 2 dollars? (assumption)

So at 2 dollars - 5.64 is a difference of 3.64 per day