Future Charging for Model S 1-phase or 3-phase ?

[jkirkebo]

If you have a big enough battery to get through a day, then you don't need fast charging - an overnight at home or in a hotel is fine.

That is true, only if you can charge at your destination. I often stay overnight at places with no charging, thus needing to charge during the day instead.

[markwj]

That is true, only if you can charge at your destination. I often stay overnight at places with no charging, thus needing to charge during the day instead.

I guess long-run it will work out like Internet in hotels. The good ones, who offer the facilities, will rise to the top. hotels seem to be the obvious place to me. No time rush, and they already have parking under their control.

[dpeilow]

There seems to be some tradition of thinking that is suspicious of fast charging and says: either "home charging only" or a hybrid.

There seem to be some early adopters that think their circumstance is widespread. This 40 miles per day on average statistic is trotted out but it's a case of lies and statistics I think. I would fall into that category, but I travel to work on the train and maybe drive 200 miles on the weekend.

I wonder how much those with a plug in hybrid to sell are influencing this?

Is this question for Zack? I'm not getting the connection. The Model S PEM?

The Roadster PEM. Essentially there is a three phase charger in it, I guess just the cooling needs to be beefed up to run continuously. But I suspected even 3 PEMs would be less than the weight quoted.

What is interesting is the fast-charger at the motorway rest stop. Somewhere you could break a trip to have lunch and refill the battery. That would close to double your range (for a given battery size) - but I still worry about all the infrastructure needed to support tens or hundreds of thousands of these.

If we get to the point where 100 EVs at a time are fast charging at a service stop, then installing a 5MW supply to that stop will be costly but not outrageous in the context of the cost of the building or a filling station.

[jkirkebo]

I guess long-run it will work out like Internet in hotels. The good ones, who offer the facilities, will rise to the top. hotels seem to be the obvious place to me. No time rush, and they already have parking under their control.

I'm not worried about hotels, I do however often stay the night at places where there is no electricity at all. Like in my cabin, the nearest powerlines are 5 miles away. Other example, some campsites or places that are a good starting point for camping trips.

Also, some trips require 5-600 miles driving in a day, I don't see 600-mile batteries being feasible in the next few years.

Many places will also offer only 16A 230V charging, that is 3.6kW and in 10 hours only 36kWh. A depleted 300-mile battery will require at least 9kW charging to fully charge in 10 hours.

[Eberhard]

for 11kW you need 16A 3-phase. if you look to the lemnet.rg or "drehstromliste" there are a lot of these already available in Europe, most in Germany, Switzerland an Austria. 32A socket are quite rare- and currently you can only one-phase on this.

[Norbert]

I wasn't expecting something from BYD to contribute to this discussion, but here it is:

Green Car Congress: BYD reports plug-in fleet test results; rapid charging not diminishing capacity

In total, BYD plug-ins have accumulated more than 1.769 million all-electric miles (2.847 million km) and have seen no diminished range or capacity due to rapid-charging.

[Norbert]

Now, (b) is certainly because of where I live, but also affects the scalability of EVs as common transportation. If you have a big enough battery to get through a day, then you don't need fast charging - an overnight at home or in a hotel is fine. Assuming an explosion in the numbers of new EVs with smaller batteries relying on fast charging to get through the day - we'll end up with so many EVs that every parking spot will have to have a fast charger. I just don't see how that is scalable.

The average daily use doesn't require a huge battery. Since batteries are (still) expensive, many won't have a battery that is large enough to also cover their above-average driving.

What is interesting is the fast-charger at the motorway rest stop. Somewhere you could break a trip to have lunch and refill the battery. That would close to double your range (for a given battery size) - but I still worry about all the infrastructure needed to support tens or hundreds of thousands of these.

While there are many other situations where fast-charging is the best solution, just motorway rest stops won't require hundreds of thousands chargers. The total number of gas stations in the US is around 120,000 (the number is shrinking). Even with fast-charging, most charging will still be done at home (or perhaps also at work). (This is meant in addition to David's great answer).

[stopcrazypp]

For all the talk about fast charge's effect on the battery, keep in mind the bigger the battery, the lesser the effect. On the battery side, all it cares about is the C rate.

For example, if you have a a 25kWh/100 mi pack, then 1C is 25kW (ignoring losses for easy math). If you have a 50kWh/200mi pack, 1C is 50kW. The bigger pack has twice the charging power, but the impact on the battery is the same. In terms of mph, the larger pack is charging at twice the "speed", even though the impact is the same.

[markwj]

While there are many other situations where fast-charging is the best solution, just motorway rest stops won't require hundreds of thousands chargers. The total number of gas stations in the US is around 120,000 (the number is shrinking). Even with fast-charging, most charging will still be done at home (or perhaps also at work). (This is meant in addition to David's great answer).

I just don't get the scalability of this.

Let's take the extreme that all gas cars were replaced with leafs. Range is 1/4 of the gas equivalent and fast charge time is at least 6 times. Without home charging, and relying solely on gas-station equivalent fast charging, that means 24 times the number of gas pumps replaced with fast charge stations.

Now, the extreme case is obviously not going to happen, but the math works out that for each gas car replaced by a leaf (as an example of a car with small battery) without home charging this is 24x the number of 'refill stations'.

I think we need a new model, not just an adaptation of the existing infrastructure. Standing around in a lousy gas-station environment for a couple of minutes is fine, but not for the 30-45 minutes of a fast charge. Parks, hotels, restaurants seem the logical solution to me (with a selection of charging options).

Each market, and even individual needs within each market, are going to require different solutions. Where I live (Hong Kong), the vast majority of car owners can't do home charging, but I am lucky in that I can.

[Norbert]

I just don't get the scalability of this.

A single well-placed fast-charging station can already be a huge benefit to those cars that are able use it.

Let's take the extreme that all gas cars were replaced with leafs. Range is 1/4 of the gas equivalent and fast charge time is at least 6 times. Without home charging, and relying solely on gas-station equivalent fast charging, that means 24 times the number of gas pumps replaced with fast charge stations.

Now, the extreme case is obviously not going to happen, but the math works out that for each gas car replaced by a leaf (as an example of a car with small battery) without home charging this is 24x the number of 'refill stations'.

I think we need a new model, not just an adaptation of the existing infrastructure. Standing around in a lousy gas-station environment for a couple of minutes is fine, but not for the 30-45 minutes of a fast charge. Parks, hotels, restaurants seem the logical solution to me (with a selection of charging options).

Each market, and even individual needs within each market, are going to require different solutions. Where I live (Hong Kong), the vast majority of car owners can't do home charging, but I am lucky in that I can.

- Fast-charging doesn't mean "without home charging". In addition to home charging, there will be other methods of over-night charging. Hotels, as you say, certainly will have charging. There are already chargers which look almost like parking meters. I'd expect that the cost of J1772 chargers will go below $500, and when deployed in larger quantities, the relative installation cost will be low enough to justify the investment wherever used during most nights. As just an idea of how this might get solved. Of course, charging at the work place will be another option.

- Not all gas cars will be replaced with Leafs, that's not a basis for a realistic calculation. Future electric cars will have larger batteries (at decreasing prices) as well as even faster charging. The Model S will already have a 300 mile battery as an option. However the Leaf is already very useable for many.

- We are not talking about locating fast-charging stations in "lousy gas stations" ("motorway rest stops" were your example). They will be mostly at places where you would want to spend some time in any case. "Restaurants" are a much better example.