How fast is fast enough (When it comes to charging speeds)?

[Joints4Sale]

I wrote this response in another thread(The Lucid Air Is the 2022 MotorTrend Car of the Year) but I think it deserves its own thread for discussion. There has been talk that the R1T/R1S will only be able charge at 200kw.

The problem currently with High Power Fast Charging is the infrastructure. After having owned a Audi e-tron GT for three months I have had mixed results getting the rated 270kw charging speeds. About a 25% success rate. The number of DC fast charging stations that can deliver a charge greater than 150kw are limited. Add to that the problem with lack of education of new EV owners. I've experienced that when arriving at Electrify America stations that have 2 350kw and 6 150kw stations, many times there are cars that can't charge faster than 150kw charging speeds plugged in at the 350kw chargers with plenty of 150kw chargers available.

By no means am I a Tesla Fan Boy. But Tesla V3 chargers are increasing at a rate faster than the competition and consistently work at the advertised rate. I've road tripped a Model Y with no charging hiccups.

Does any of this matter if you primarily charge at home? Only in public perception. Most people don't road trip their cars and rarely drive more than 250 miles in a day. But they have this innate fear that they'll be stranded by the side of the road.

I thoroughly enjoy a good road trip and have been known to ride my motorcycle 1000 miles in 24 hours(see also Iron Butt Association). My family on the other hand does not enjoy driving those kind of distances.

So in reality, If a car can charge to 80% in 30 minutes then that is good enough for most use cases.

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[ajdelange]

So in reality, If a car can charge to 80% in 30 minutes then that is good enough for most use cases.

I suppose that depends on who you are and where you are in life. For someone engaged in leisure travel then yes, it is certainly fast enough. For a road warrior trying to squeeze a an extra meeting, perhaps not.

Now that range anxiety is beginning to fade from the consumer's radar (finally!) I think the marketeers have seized on charging speed as the big competitive factor. Do I care if I'm at a charging station for 40 min vs 30? No.

Do I care if a DCFC I have selected is only 25% likely to work when I get there. That's a different matter. Surely it isn't that bad.

 

[CharlieSA]

Not a kw number but concept. I’d say it can charge 2 hours of highway driving in 15 minute to top off, then maybe a 45 minute stop for lunch where I can charge longer. So let’s say driving 75, it’s 150 miles, so probably closer to 180 miles of “range”. Charging that is probably close to. Depending on vehicle size that might be 50-60 kWh. So that backs into a charge rate of 200kw.

as mentioned above I would be comfortable building a small deficit at each charger that I can make over a longer lunch break. So I’d say 150-170 is probably ok for me

 

[sub]

I think the focus on peak rates is 100% marketing nonsense. I also do not think that the time for 20%-80% is a useful metric either.

The number I care about is the time to add 200 miles of range. On a car with a 250 mile range that is 10%-90%. On a car with 400 miles of range that is 10%-60%. Or on a car with 600 miles of range it is 10%-43%.

As far as what is "fast enough":

I find that on a road trip it is best to get out of the car for a few minutes every 3 hours or so anyway. If the car can replenish 3 hours of driving in the time that it takes me to go to the bathroom and grab as snack then the charging experience is non-intrusive.

Right now most chargers are located in huge parking lots for huge stores (walmart, target, etc) so it takes a pretty long time to get to the restroom. 200 miles in 30 minutes is fast enough. If they start putting chargers at roadside rest-areas where the restroom is 50 ft from the parking spot I'll start wishing I could get that 200 miles in 10 minutes.

 

[Dark-Fx]

30 minutes every 2-2.5 hours of driving is a good speed for me if I'm traveling with my family. If it were myself, I'd prefer it to be closer to 15 minutes per 4 hours of driving.

Longest I've ever driven non-stop by myself was a little bit over 500 miles in ~ 8.5 hours. I had to pee for probably about two hours before my car decided it was time for a drink. Anyone who says they need 500 miles of range without having to stop to charge is just arguing in bad faith.

 

[ajdelange]

I think the focus on peak rates is 100% marketing nonsense.

It is.

I also do not think that the time for 20%-80% is a useful metric either.

More useful than the peak number. What you really want to know is how long it takes to nominally add 1% and this is about 0.6 minute i.e. about 1% of an hour is required to add about 1% of charge.

The number I care about is the time to add 200 miles of range. On a car with a 250 mile range that is 10%-90%. On a car with 400 miles of range that is 10%-60% (or 20-70).

On a 250 mile rated car 200 mi is 200/250 = 4/5 = 80%. It will take you nominally 0.6*80 = 48 min. to add that. On a 400 mile range car 200 miles is half that battery and it will take nominally 30 minutes to add.

If it's not already apparent these numbers are based on a nominal charge rate of 1C. The word "nominally" peppers this post because all charging does not take place at exactly 1C. Ad we all know it is faster at low SoC and slower at high so that we know that we can probably add 10% to 30% SoC faster than we can add it to 70% SoC. We are also aware that the manufacturers are pushing for nominal rates faster than 1C. It shouldn't take too many fasc charges for you to be able to figure out what the nominal rate for your vehicle is so that, it for example, it is 1.2C you can us 0.5 min per % instead of 0.6 (1C rate).

 

[sub]

Anyone who says they need 500 miles of range without having to stop to charge is just arguing in bad faith.

Need, no. But really nice to have, yes.

The more range you have, the less you need to plan for having 100% of your stops be located at the relatively sparse charging stations and you also have more freedom to make short charging stops that don't completely replenish what you used.

Say you start the day with 500 miles of range. If you drive 200 miles, and then stop for 10 minutes you may not have fully replenished the 200 miles that you used, but you might have added 100 miles (20%). No big deal - you now have 400 miles of range which is plenty to get back on the road again. If you repeat the pattern of driving 200 miles and making a short 20% charge stop, 500 mile vehicle can make it 800 miles (12 hours) before need to stop for longer than it takes to add 20%.

 

[SeaGeo]

The problem currently with High Power Fast Charging is the infrastructure. After having owned a Audi e-tron GT for three months I have had mixed results getting the rated 270kw charging speeds. About a 25% success rate. The number of DC fast charging stations that can deliver a charge greater than 150kw are limited. Add to that the problem with lack of education of new EV owners. I've experienced that when arriving at Electrify America stations that have 2 350kw and 6 150kw stations, many times there are cars that can't charge faster than 150kw charging speeds plugged in at the 350kw chargers with plenty of 150kw chargers available.

Out of curiosity, which part of the Country are you generally in? EA has I think *a* hardware vendor that still seems to continuously have trouble communicating with the Taycan and Etron GT.

The latter part is primarily about education (at the moment). It's also part of the reason I get annoyed when manufacturers (ahem Rivian) don't communicate adequite information about the charging capabilities of the vehicle.

On a side note, all RAN chargers will be 300kW+ capable, so they shouldn't have the mix and atch issue.

I think the focus on peak rates is 100% marketing nonsense. I also do not think that the time for 20%-80% is a useful metric either.

The number I care about is the time to add 200 miles of range. On a car with a 250 mile range that is 10%-90%. On a car with 400 miles of range that is 10%-60% (or 20-70).

I generally agree, but I just don't think there is one metric that handles everything well. I quite like the start/stop SOC matrix charts InsideEVS has made over the last year that shows time and average kW, and (IIRC) miles gained for any 5% increment.

Part of this is just observing various cars and different charging needs. I'd argue peak becomes useful to know from a maximum hardware capability standpoint, and what you can get with short stops. you want to push 200 mile intervals, I may want to do shorter intervals. Or Joan may need to start towing and understand how long jts going to take to recharge to 80% because her rated mileage will be way off.

And just in geneal for debugging. Efficiency is so driving dependent, rating a car recharge based on mileage and a GOM leads to confusion, and it's obscuring that's actually being being billed, and the performance of the car. I know what kW to expect with my ID.4 at X percent thanks for InsideEVs. However if I go off what's presented in the car (miles per minute or miles per hour) I will see a significantly different answer depending on hour I'm driving for the same kW charging rate. Which can lead people to think that their car or the charger is malfunctioning.

Knowing peak rate also helps address Joints complaint about people using chargers that can output much more than their car can handle.

's not already apparent these numbers are based on a nominal charge rate of 1C. The word "nominally" peppers this post because all charging does not take place at exactly 1C

Building on this, and I know you know this AJ, there are a lot of cars where I don't at all care about the nominal C rate for a full charge. IIRC The MME is currently like 2.5 hours to recharge to full, but just 42 minutes to 80% (because Ford made what's probably the dumbest curve on a production car at the moment). So you're encouraged to minimize charging times and intervals to keep the max speed the highest.

But I think potentially more interesting is the Lucid. It's nominal is right around 1C, but because of the range, efficiency, and charging curve (hopefully) most people will sit in the 5 to 40 or 60% range where the average C rate is ~2, and they'll still be getting 200 to 300 miles of range. it's funny, I'm a little disappointed in their charging curve overall for now, but the combination of the curve and range of thst car just starts to break how most people think about EVs. Which speaks to @sub concept of miles added (as much as it annoys me).

 

[lefkonj]

Charging time is such an individual thing. I own my house and installed a 50AMP charger that will cover me over night, not a problem. Plenty of people live in Apartments or Condos and can't do this, so they will be relying on public charging infrastructure. Having said that for how more than half of the country drives 30 minutes to get 80% is perfect, considering the average American drives only 250miles a week. If I was a sales person who drove 30k a year this could be a problem but most likely it isn't as I could get the miles I need for the day in 30 minutes or overnight.

Range anxiety is the same as being new to scuba diving 'Will I run out of air' 'What if I can't breath'. Do it a few times and you realize it is fine 99% of the time. At least with range anxiety a mistake won't get you killed.

 

[riburn3]

Faster charging speeds, at least on road trips is a pretty big deal. For most EV owners, with many keeping a family gas vehicle, it's a non issue, and the rest of EV owners just charge overnight in their garage where speed matters little.

On road trips though, time is of the essence. 20-80% or whatever metric is fairly meaningless, as most of the time the goal is to fill up at one charger with enough juice to make it to the next charger. Considering most EV chargers on the EA network and Tesla network are positioned 120 miles apart or even less, you often find you just need to charge to 50 or 60% in order to make the next charger comfortably. Sitting around and trying to top off on these trips is a waste of time. Range is also fairly meaningless outside of perhaps the Lucid after the initial stop.

I've done lengthy road trips in a Model S, Model 3, Model X, and Taycan, and without a doubt, the Taycan is the fastest road tripper. I consistently can sustain speeds over 250kW at EA stations, and it typically won't taper until 50%. Even when knocking on 80% I will get close to 125kW. At most stops, 10 minutes is all I need before I'm on my way. In the Model X we owned, it had the 22" wheels and at interstate speeds, would often demand a deep charge taking over 45 minutes per stop as the 200+ mile range was really more like 125 miles. Same for our older Model S. Our current model 3 can sustain faster chargers longer, but nothing remotely close to a Taycan, which also has a much more accurate range predictor and severely underestimated real world range.

 

[Denver_Paulie]

Not trying to be flip, but the key to long distance driving in an EV is patience. There are lots of things out of your control, so you just have roll with it and be prepared for the unexpected.

Electrify America can be inconsistent, so you may charge at 200kW at one charging location, but only get 85kW at another. Or, there may be two Chevy Bolts taking up both of the working Electrify America charging stations at a particular location, so you have to wait 45 minutes for your turn to charge.

I have driven 40,000 miles in two different Taycan's and an Audi e-Tron. Been to 12 states in those vehicles and used a lot of different Electrify America chargers. The one thing I have learned is that there is very little consistency in charging speeds, and to have patience because you are always not going to get that amazing charging session.

The good news is that in all those miles and all those states, I have only been inconvenienced once - and that was on a trip from Denver to Kansas City and the Electrify America location in Salina, KS was only charging at 34kW. I ended up getting a hotel and using their L2 charger over night to continue the drive the next morning.

 

[Taycanfrank]

@Denver_Paulie nailed it. My experience mostly mirrors his.

You can sit and plan based on weather, getting the battery to the perfect temperature, choosing the highest kw supercharger all you want.. sometimes that charger is randomly going to sit you at 80 kW and that's what you're going to get.

Using 3rd party apps like Plugshare help tremendously, as generally (but not always) it's certain locations that have more problems or slower speeds.

One note on the Rivian is it will likely be one of the least efficient EVs on the market. That means you should expect to sit at chargers for longer to achieve the same result.

As mentioned above, the Taycan is one of the most efficient EVs and can consistently hold higher charging speeds than the max of the Rivian, but I still spend about 20-30 minutes to get 200 miles of range on average.

For the Rivian I would plan on 45 min to an hour stops to get 200 miles of highway range

 

[riburn3]

Not trying to be flip, but the key to long distance driving in an EV is patience. There are lots of things out of your control, so you just have roll with it and be prepared for the unexpected.

Electrify America can be inconsistent, so you may charge at 200kW at one charging location, but only get 85kW at another. Or, there may be two Chevy Bolts taking up both of the working Electrify America charging stations at a particular location, so you have to wait 45 minutes for your turn to charge.

I have driven 40,000 miles in two different Taycan's and an Audi e-Tron. Been to 12 states in those vehicles and used a lot of different Electrify America chargers. The one thing I have learned is that there is very little consistency in charging speeds, and to have patience because you are always not going to get that amazing charging session.

The good news is that in all those miles and all those states, I have only been inconvenienced once - and that was on a trip from Denver to Kansas City and the Electrify America location in Salina, KS was only charging at 34kW. I ended up getting a hotel and using their L2 charger over night to continue the drive the next morning.

Great points. In all fairness though, many of the same issues EA has occur at Tesla Superchargers as well. Just look on plug share and you will see Tesla stalls will give lesser charge than other stalls, or some stalls will be down for maintenance periodically. More commonly now, crowded chargers mean the shared power stalls won't get full juice and your charging speed is cut in half. As Tesla appears poised to add charging capability to non Tesla EVs, this will continue to be an issue until all their chargers upgrade to v3.

I've had good luck on EA 350kW chargers coast to coast along I-10 from California to Florida from my home base in West Texas. Although it hasn't always been flawless, more commonly I end up dealing with someone using a 350kW stall on their car that can't support the speed, as opposed to just getting low speeds in general. Even then though, even the 150kW stalls hold that for a long time and it is very rare for me to have to charge longer than 20 minutes between stops, and if I do its because I was eating or running into the Walmart the EA is at.

 

[SeaGeo]

@Denver_Paulie nailed it. My experience mostly mirrors his.

You can sit and plan based on weather, getting the battery to the perfect temperature, choosing the highest kw supercharger all you want.. sometimes that charger is randomly going to sit you at 80 kW and that's what you're going to get.

Using 3rd party apps like Plugshare help tremendously, as generally (but not always) it's certain locations that have more problems or slower speeds.

One note on the Rivian is it will likely be one of the least efficient EVs on the market. That means you should expect to sit at chargers for longer to achieve the same result.

As mentioned above, the Taycan is one of the most efficient EVs and can consistently hold higher charging speeds than the max of the Rivian, but I still spend about 20-30 minutes to get 200 miles of range on average.

For the Rivian I would plan on 45 min to an hour stops to get 200 miles of highway range

I suspect a lot of the taycan issues come down to specific suppliers for EA not getting along well with it for whatever reason. As long as my battery is properly warm, I've hit the "proper" charging profile with the ID.4 every time I cam recall except with the charging stations that were at the landing in Renton which has since been replaced.

Don't forget though, RAN is (supposedly) coming. So inconsistencies should be a lot less of an excuse. Patience with an EV is key, but reliability issues aren't a great reason to expect a fast charging experience (you obviously have been after that with taycan though).

Personally, since the R1T is limited to ~200kW, my "too slow" is anything other than Holding that speed deeper into the pack than the EQS, because of how inefficient it is.

 

[SANZC02]

@Denver_Paulie nailed it. My experience mostly mirrors his.

You can sit and plan based on weather, getting the battery to the perfect temperature, choosing the highest kw supercharger all you want.. sometimes that charger is randomly going to sit you at 80 kW and that's what you're going to get.

Using 3rd party apps like Plugshare help tremendously, as generally (but not always) it's certain locations that have more problems or slower speeds.

One note on the Rivian is it will likely be one of the least efficient EVs on the market. That means you should expect to sit at chargers for longer to achieve the same result.

As mentioned above, the Taycan is one of the most efficient EVs and can consistently hold higher charging speeds than the max of the Rivian, but I still spend about 20-30 minutes to get 200 miles of range on average.

For the Rivian I would plan on 45 min to an hour stops to get 200 miles of highway range

Not sure the most efficient is the term you were looking for. The EPA ratings are Between 42 and 48 kWh per 100 miles for the Taycan which is not that much better than the R1S for efficiency which is rated at 49 kWh per 100 miles.

The id.4 is between 34 and 36 kWh per 100 miles and the Tesla Model 3 is between 25 and 30 kWh per 100 miles, both quite a bit more efficient than the Taycan.

They do have higher charging curves and will charge faster, the question would be how much wear and tear that will have on the batteries if those high charge rates are used frequently.

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