Hacker News Reader

Comment by revelation | Hacker News Reader

Because the battery swap model doesn't exist. It's a cool idea, but it's not right here right now.

Drivers are already using battery swap stations in Israel and a few other test areas. Swap for a full battery takes less than 5 minutes. The cars built to work with this system are Renault and Nissan I believe. Check out the standardized batteries (drivers subscribe to a 'battery plan' so any full battery is works the same).

video: Drive Switch Go - Better Place

short video http://youtu.be/VR3oLV4fdcE longer video http://youtu.be/S3Os25gP4yA

//edited to add video links

Battery swap technology constrains car design. The Model S, I believe, sandwiches the battery packs throughout the car to avoid one big lump of mass sitting somewhere.

While I think the battery swap idea is a good one, it has many problems, not the least of which is getting all the manufacturers to agree to a myriad of standards. And agreeing to many of those standards means delegating part of your design process.

It's beyond difficult for costumers to agree on 30min waits between 3h runs.

I've been in a Better Place car here in Israel and experienced the swap, it works. Also, Shai Agassi recently completed a full cross country trip (North to South). Small country, but still.

What makes you think this is not a viable solution?

Israel is only 263 miles from north to south. The Tesla S (85kwH)can go 300 miles. Seems like the Tesla might be overkill for that country.

Hmm,

This seems to be a perfect use case for Israel.If you are a regular office goer, charge once and may be use it for a whole week and half.

"Small country" is a bit of an overstatement. If Israel was a US state, it'd be the 47th largest.

You mean the 3rd smallest? That doesn't sound very big.

Exactly. It's about the same shape and size as New Jersey (smaller actually). I can't count the number of times I've driven across the entirety of New Jersey without a second thought because I wanted a cheeseburger.

One poster says Israel is around 263 miles north to south. So you drove ~250 miles many times just to get a cheese burger? Seriously?

New Jersey is about 170 miles North to South from the tips. But parent said "I've driven across New Jersey," which can be as little as 40 miles East to West depending on where you measure from.

It was about a 75ish mile trip now that I look at it on on google maps, that was the closest White Castle there was. ;)

In any event, New Jersey would make a really small country. I know of people in this country who have to drive further to do their shopping.

You can build swap stations incrementally though just like they are building these supercharging stations, so I don't see what the difference is, other than swapping is quicker/better.

> quicker/better

Quicker may be true, but "better"? Swap stations are more expensive, they constrain vehicle design, battery shape, and battery technology upgradeability. This makes the vehicle some combination of heavier, less safe, or more expensive (pick your poison).

People don't seem to realize that the limiting factor for charge rate isn't current. It's cooling. A far simpler solution would just pump coolant through the charging port so that a large off-board cooler can be used. The cells in the Leaf and Volt could be fully charged in 20 minutes with adequate cooling. Independent (though amateur) tests by RC hobbyists have demonstrated hundreds of cycles at that charge rate with little loss in capacity.

http://www.rcgroups.com/forums/showthread.php?t=672512

  cooling

The Roadster has a water-cooled battery pack, and I assume the Model S does too.

It's not the size of the pipes. It's the size of the chiller.

You're forgetting that in the case of Telsa's car the entire battery pack is a part of the undercarriage and hot swapping in that case is quite difficult.

I've heard otherwise: hot-swapping was a design goal if not yet supported.

Reply on news.ycombinator.com