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Comment by larrik | Hacker News Reader

Wow, as someone who's never even seen a true electric car up close, I'm curious how you can keep it going for a full day of work. Charging it takes hours, right? Unlike gasoline which you can just pull in and be back on the road in a couple of minutes.

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50,000 miles a year is only 200 miles a day (assuming 2 weeks of vacation), the tesla can do that range without any charges, he just needs to have enough charge an usually long trip at the end of the day. At the rates taxies charge, someone who goes for farther than the charge of a Tesla is going to make the news just for their bill - even if the trip is in a normal gas car.

I expect that he plugs in over lunch hour, and at bathroom brakes. This won't get him to full charge, but it is enough to ensure that he can handle a long trip. If he is ever at less than half charge he has made enough money that he can afford to take an hour off to charge.

Not only that, but he'll save time by not having to go to a gas station like regular taxis do.

If he's driven it 100,000 miles in 2.5 years, and assuming 250 working days a year, it's only 160 miles a day, well within a Tesla's range. He can probably charge it fully at night and have plenty for each day.

The Supercharger stations can charge 50% of the battery in 20 minutes.

Do the superchargers have a detremental effect on the batteries? I would have thought rapid charging would lead to greater wear than a slow steady charge. Anyone know?

They do yes. You should only use it when traveling and can't charge it overnight.

The superchargers might have an impact on battery life, but in practice they don't seem to have much impact. The reason is that unlike all other electric cars, they heat and cool the battery pack. The reason why leafs do have a demonstrated huge impact for using their dc fast charging (chademo) is because their batteries get really hot when using chademo. The tesla cools the batteries when charging, heating if necessary too, and that's why people don't such much or any impact on range over time, even when using super charging.

A more aggressive charge cycle will affect battery life-cycle, but even the Super-Chargers don't pack enough current for it to be really detrimental.

110v is just woefully inadequate for charging a pack that large.

Not from what I've read. The Tesla battery pack has some sophisticated heat management capabilities that dump the excess heat generated while super charging.

The most damaging things you can do to the batteries is keeping them 100% fully charged or completely discharging them.

Yup, not an issue. When you're charging at 120kW the whole car hums and cooling system is going full-tilt. Pretty incredible to see 400VDC @ 300A go straight into the pack.

If you run the math its only roughly 170 continuous horsepower running thru those power cables, assuming 100% efficiency etc.

If they added another order of magnitude or two to that charge rate, then it would be impressive.

You have to take into account that the electric motor in a tesla is more efficient than a gas motor (3-4x). The reasoning is that a gallon of has has about 33.6kwh in a gallon (see wikipedia (https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equi...). A tesla has 75 or 85 or 90 kwh onboard, so that's at most 3 gallons of gas!

Another way to think of it is that mpg equivalent of evs is around 90-100 mpg. The model S is a huge heavy car, and look how far it can go on 85kwh.

The article cites approximately 50,000 miles per year. At 5 working days per week of driving, that would equal approximately 190 miles per day. The Model S page on Tesla's web site calculates that at 45 mph with the AC on (a reasonable speed for city driving) the Model S can get nearly 290 miles on a full charge [1].

In addition, if there is a Supercharger unit available, the Model S can recharge fully in less than an hour if less than 260 miles have thus far been driven [2]. Meaning it could be back at full charge following a typical lunch break period.

[1] https://www.tesla.com/models#range-calculator

[2] https://www.tesla.com/models#savings-calculator

No supercharger in Quebec City, but some destination chargers.

https://www.tesla.com/en_CA/findus?redirect=no#/bounds/46.98...

> Wow, as someone who's never even seen a true electric car up close, I'm curious how you can keep it going for a full day of work. Charging it takes hours, right? Unlike gasoline which you can just pull in and be back on the road in a couple of minutes.

Right and wrong. 110v charging would take days. Supercharging takes minutes.

I don't drive a Tesla, I have a Leaf. 110v is enough to recharge overnight for my commute (~20 miles each way). Or about a couple of hours charging at work. Not an issue for commuting.

Were it used as a Taxi, I'd have to rely on quickchargers. About 20 minutes from 20 to 80% SOC. It's not linear, so very low and very high state of charger takes longer. A Taxi Leaf would likely be doable for a dense city, very bad for highway driving, as speed kills range (for any kind of car).

For a Tesla it's not an issue.

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