Monday, June 20, 2016

Electric car batteries, charging time, and how far you can drive

Interesting post from Robert Graham on how far you can really drive your Tesla and when you can expect to get stranded (and for how long).

The only thing that seems to be missing is the impact of climate control on your range.  Air conditioning draws amps from the battery, and heat draws even more.  You will drive furthest on a beautiful spring or autumn day than in the hot summer or freezing winter.

Shorter post: green philosophy gets pwned by engineering constraints.


SiGraybeard said...

Four word version: physics is a bitch.

I've always been fond of the version that goes Physics doesn't care what you think.

BC said...

Top Gear UK did a show on this topic a while back. They made it half way to their destination before they had to push the cars to a local university since there was no place else to charge them up.

They used econo-boxes, but same overall guidelines apply!

abnormalist said...

I love how people view this as a "And thats why electric cars are impossible" rather than the "look how far these have come in an amazingly short period of time" as it should be.

Current generations of tesla cars are designed to have the battery replaced within 15 minutes by robots. The idea is that rather than stopping to fill up your car, you stop, swap the battery and keep going in less time than it takes you to drop a deuce in the gas station.

At this point though they've dropped that idea. People aren't interested when the super chargers are cheaper, and nearly as good.

10 years ago we would be STUNNED by something that could charge the electric car to 90% in 60 minutes. What used to be a novel idea has actually become a practical solution for a significant number of people.

Is this the future? Probably. At least this or something like it. As more people start driving these, the improvements will come faster and faster. Eventually it will be as easy as filling your gas tank is today, but arguably safer, and with fewer environmental issues.

Yes I am saying that climate change aside, oil is a nasty nasty item. It DOES pollute, CO2 completely ignored. Hydroxides are not exactly good for life of any type, as well as good ol fashioned CO. Add in that the logistics of shipping and refining oil have caused countless incidents in nature with oil pipeline spills, tanker mishaps, refinery fires, etc.

In 30 years the idea of filling up your hot rod with a big ol greasy tank of explosive dinos will be considered as old fashioned as running a steam engine, or riding a horse somewhere is today. Likewise though, they will still be around, and enjoyed by enthusiasts.

Borepatch said...

Abnormalist, there has indeed been a lot of progress - regenerative braking, electric motor efficiency, and computer control/synchronization have all led to advances. But not much as far as battery technology. And power requires a power store.

Probably the biggest fundamental technology leap forward would be a different battery technology with 10x improvement in storage capacity.

abnormalist said...

Honestly BP, I'd settle for lighter, more compact with higher charging rate. I think we could realistically get to a 300 mile charge, with a 30 minute recharge period with incremental improvements to existing LiPo technology.

At that point, it becomes an issue of cost reduction and infrastructure to get to the point where the electric car is a workable reality across America. Right now I lack the infrastructure to consistently fill my gasoline cars at home, but since they generally can go 3-400 miles without filling up, its a non issue. Wouldn't it be handy though to come home with an empty tank, and just fill her up in the garage? Like its nothing?

We're long past the point of the 70-80 mile range of things like the GM EV1, and we're moving forward in leaps and bounds.