Comments on: Tesla Death Watch 9: 8-Hour Recharge Time. In Theory.

By: Atreus

Atreus — Sat, 06 Jun 2009 15:10:33 +0000

Tesla states in their battery system blurb that the battery stores 53 KW hours of go juice . Average cost of electricity is about 10 cents/kwh. This works out be about 2.5 cents per mile if the 200 mile range is correct and conversion losses due cables etc are held to a minimum.

By: charlessain

charlessain — Wed, 30 Jul 2008 16:16:51 +0000

Time to charge aside, does anyone know how much power it takes to fully charge a roadster? How many kilowatt hours does a full recharge consume?

By: doug

doug — Mon, 07 Jul 2008 16:56:36 +0000

Wulv: Yikes 8 hours to recharge, even on a 220v circuit?

Ugg… sorry to sound bitter, but didn’t anyone learn this stuff in high school? Ya see, besides Voltage (kinda like the pressure in your garden hose), there’s also Amperage aka current (the rate the water is flowing). Voltage is measured in Volts which is defined as Joules (J, a unit of energy) per Coulomb (C, a unit of electric charge). Current is measured in Amperes (or Amps, A) which is defined as Coulomb per second. Now what happens if we multiply Volts times Amps?
V x A = J/C x C/s = J/s = W
A Watt (W) is defined as Joules per second. That’s the amount of energy per unit time, also known as POWER. Power is what counts here people!

There are other factors, but to first order you can get an estimate of how long it will take to charge the battery based on the amount of ENERGY you need to put in that battery and the RATE at which you can supply it. This rate is the POWER you have available. Guess what! ENERGY divided by POWER equals TIME!
For the love of all that is holy, PLEASE LEARN THIS!

By: Wulv

Wulv — Mon, 07 Jul 2008 15:26:29 +0000

Yikes 8 hours to recharge, even on a 220v circuit? Yeah the range itself would be practical to some people, but 8 Hours to full charge? I guess that makes it much less a daily commuter than I thought may be possible. Certainly not a (short) road trip car, even if you found sites with 220v charge stations.

By: J.on

J.on — Mon, 07 Jul 2008 14:51:25 +0000

I only use my garage as ¼ landfill =). The rest is used for German automobile and bike (cycling) storage.

I think that while the ‘idea’ of the Tesla is fantastic, its execution (no pun intended) has been anything but. Since I personally have never taken a road trip longer than 150 miles, and my daily commute is about 15-20 miles, a car like the Tesla would be prefect for me. However, it is far out of my (and most peoples) budgets.

And yes, a $30K sedan is a wonderful initiative; methinks that it will never exist, at least not from this California-based company.

By: Kevin

Kevin — Mon, 07 Jul 2008 05:08:26 +0000

Oh all I have to do is pay an electrician $1500 so that I can recharge my car? Well, that’s MUCH easier than going to the gas station for a refill. This decision gets easier all the time.

Seriously though, this may be no big deal for the eight billionaires who are going to be buying those Tesla roadsters. But if Tesla really aspires to have some mass market $30,000 sedan in a few years, this kind of thing is a big problem. You tinkerers may think its fun to re-wire your garage, but 98% of households will NOT be doing that just so they can buy a certain car. It’s hard enough finding people who don’t use their garage as a landfill anyway.

By: Stein X Leikanger

Stein X Leikanger — Mon, 07 Jul 2008 04:59:09 +0000

@Stephan Wilkinson
Doesn’t anybody here understand electricity, or only gasoline? You’ll need to catch up soon.

I would argue that quite a few people don’t understand gasoline, either. :-)

By: Stephan Wilkinson

Stephan Wilkinson — Mon, 07 Jul 2008 01:08:04 +0000

The power that comes into your house is 220/230 volts. I have several receptacles that I easily wired myself to access 230v, for my air compressor and several other large accessories.

Doesn’t anybody here understand electricity, or only gasoline? You’ll need to catch up soon.

By: RedStapler

RedStapler — Mon, 07 Jul 2008 00:36:02 +0000

You can hire any electrican to add another breaker to your service panel and run 220 to your garage. It should run you $600-1500 depending on the length of the wire run and whatnot.

Heck if you can even do it yourself if you are technically inclined.

Most of the owners could afford fancier exotics are buying this thing for “smug” bragging rights. An extra $25-40k to put a Solar Electric system on the roof the their house and the operational carbon footprint is effectively zeroed.

By: Kevin

Kevin — Sun, 06 Jul 2008 23:20:13 +0000

doing: Putting that quote in context, you’d understand that it would take about 8 hours to recharge on a 30 Amp, “220-volt circuit like those used to power a home oven or electric dryer.”

Hey I just double-checked my garage and the only outlet in there is 110v. Am I supposed to park the Tesla in my kitchen?

By: seabrjim

seabrjim — Sat, 05 Jul 2008 19:25:38 +0000

I read that too quickly Stephan. My mistake!

By: Stephan Wilkinson

Stephan Wilkinson — Sat, 05 Jul 2008 18:50:32 +0000

Who sez you have to plug a “lamp cord” into a 110-volt socket? Nothing says you can’t use 12ga wire.

By: seabrjim

seabrjim — Sat, 05 Jul 2008 17:28:55 +0000

Lamp cord to charge my $100,000+ sports car? Maybe they are out to obliterate fords record for the most garages caught on fire. What are these people smoking?

By: doug

doug — Sat, 05 Jul 2008 17:02:47 +0000

Ya know, Robert, if you took the time to learn a little math and some basic E&M, all this wouldn’t be so confusing for you. Putting that quote in context, you’d understand that it would take about 8 hours to recharge on a 30 Amp, “220-volt circuit like those used to power a home oven or electric dryer.”

By: Stein X Leikanger

Stein X Leikanger — Sat, 05 Jul 2008 15:12:59 +0000

I’ve never thought much of the Tesla, and they’re not doing much to help me change my mind, are they?

Silly people.

By: improvement_needed

improvement_needed — Sat, 05 Jul 2008 15:00:32 +0000

Potential Tesla owner and “media company executive” Gary Patrick was realistic about the car’s core appeal: “”You can still feel like you’re fulfilling your green responsibility and reducing your carbon footprint with a car like this.”

green is not only about carbon…

IF consumers were actually SERIOUS about being eco-friendly, they would shun vehicles like the tesla all together

nothing says eco-friendly like selfish indulgences…

By: LoserBoy

LoserBoy — Sat, 05 Jul 2008 14:55:32 +0000

“You can still feel like you’re fulfilling your green responsibility and reducing your carbon footprint with a car like this.”

Yeah, I suppose the carbon footprint of Nothing is pretty small, Mr. Patrick.