Battery Swapping: Tesla’s Plan Includes Getting the Old Pack Back

By · April 28, 2011

Revenge of the Electric Car, Panel Discussion

Panel discussion following screening of Revenge of the Electric Car. (Photo: Rick Kim Photography)

One hundred miles. That’s the range of most electric cars, and if you want to go further, take the gas guzzler. But there’s a controversial alternative that can turn range anxiety vehicles into range champs: battery switching. Suppose you could drive 100 miles, take a quick detour into a switching station (five minutes or less), and take off again with a fresh pack? It’s more than possible—the technology is here now.

First championed by charging company Better Place in its bid to wire Israel, battery switching still induces much skepticism among automakers, and only Renault among mainstream automakers has embraced it (in Renault Fluence Z.E. cars for its partnership with Better Place). But Tesla is also planning switchable batteries for its new Tesla Model S electric sedan. That plan came under discussion last week at the Tribeca Film Festival premiere of Revenge of the Electric Car, which was followed by a panel that included Elon Musk of Tesla, Carlos Ghosn of Nissan, Dan Neil (a Wall Street Journal auto writer heavily featured in the film) and the filmmaker, Chris Paine.

The Model S will actually be introduced in a model with a huge battery pack (as much as 95 kilowatt hours) intended for 300 miles on a charge. That one won’t need to switch batteries too often, but there are two other editions with 160 and 230-mile range that could take advantage.

“We’re designing the Model S to have switchable batteries,” said Musk, who has a solution to the problem of consumers not wanting to end up with an unknown pack in their expensive EV. “When people take an occasional two-way long distance trip, they’ll get a replacement pack and then pick up their original one on the way back. The issue of giving up your one-year-old pack for a three-old-one goes away.”

I like that concept, for exactly the reasons Musk states. If I’d spent $77,400 on a Signature Edition Tesla Model S, I think I’d want to keep track of its ultra-expensive battery pack. Would you calmly swap engines on your Porsche?

Neil, whose Pulitzer Prize carries weight, is skeptical that swapping is viable. “The battery is the most expensive part of the car,” he said. “Does it really make economic sense to have these valuable packs lying around?” He also questioned Tesla’s ability to deliver on its every claim for the Model S, due out next year, and in the Green Room arranged a bet with Musk on the subject. Making the battery pack switchable definitely does add a layer of complication.

Ghosn countered that it’s no longer a question of “if” when it comes to swappable batteries. “Come to Israel and see for yourself,” he said. “In June we’ll be rolling it out on a massive scale.” Better Place has committed to buy 100,000 of the switchable-pack Renault cars, which are already on the ground in Denmark.

I know that battery switching works, because I saw Better Place do it in less than a minute in Tokyo with Nissan EVs. It’s completely automated, and very impressive to see. My personal view, though, is that it works best for single-model fleets such as taxis, buses or rental companies. There’s a central depot that could double as a switching station, and—best of all—one battery pack to stock, instead of the plethora that will be on the road in a few years.

Switching is a core part of the Better Place strategy, so it will get a pivotal airing from the company, just as the Revenge of the Electric Car is in full swing.


· · 6 years ago

Probably the people most upset will be the ones who bought a brand spanking new car with a battery pack that still has that new battery pack smell, and on the first battery pack change, they get someone's old pack (assuming the car has been in production for a while) that's already showing signs of range reduction.

· · 6 years ago

I'm with you on this one, Michael. The battery swapping business model makes a lot of sense for fleet vehicle owners. I understand that it's working great for the Tokyo Taxi Company.

But, yes . . . I'd be a bit leery about taking any old recharged battery while on a long trip. I'm also wondering just how efficient it would be to truck around a multitude of different battery sizes and types all over the country, so that these swap stations are always guaranteed to have your particular battery, freshly charged and ready to go.

I am glad to hear, though, that idea of being able to get back your original battery after returning from a long round trip is being thought out.

· · 6 years ago

Why not just a network of car dealerships where the batteries are stored? I buy a Tesla, I plan on a trip, I need to find a Tesla dealership along the way. Sure, I'm swapping out my expensive battery pack, but am I not getting an equally expensive battery pack? I buy a LEAF, then I find a Nissan dealership. Why rely on a third party to provide this service?

· · 6 years ago

I like FamilyGuy's idea of having swapping stations at dealerships. I imagine this would have other benefits for the dealerships as well, customers would spend far more time in Tesla dealerships swapping battery packs (if the owned a Tesla) than in Nissan dealerships so would see new Tesla developments sooner and be more likely to buy another Tesla when the time came to replace their current car. This brand loyalty would be more important to new manufactures like Tesla i would have thought than already established ones like Nissan or Ford.

· · 6 years ago

Modular components sound like an excellent idea. Very space-age!

Some concerns and questions:

-The facility storing the packs (The gas station or dealership) will have to be like Fort Knox.
-Weather; Ice and snow. Can the packs be removed from inside the car where the environment is controlled?
-Condition of the new battery pack. (I know how much I hate getting a crappy propane tank for my new grill...and that's only $16!)
-Will this process be automated, attended or self serve?
-Can I buy a spare pack and keep it on the charger at home like I do for my cordless drill? Can I take it with me and swap it out myself on the road?

· · 6 years ago

A few comments on swapping:
1) Better Place was not the ones who "First Championed" swapping. The original Impact (prototype to the EV1) was designed to enable battery swapping. That was the reason for the "T" shaped battery that lives today in the Volt. It was supposed to be able to slide out the rear of the vehicle. The "T" enabled some of the battery weight to be forward so the car wasn't rear-end heavy. It ended up being troublesome so they skipped that capability in the EV1.
2) In the '90's, when a lot of effort went into EV research, all attempts at swapping had poor results. It turns out that it is very difficult to quickly and regularly move something that weighs a half ton or more. Anyone who has worked with forklift battery swapping can testify to this. Fast charging was proving to be a lot less effort so most folks were leaning that direction before the auto industry managed to kill the entire effort. As you dig into it, fast charging gets easier as you learn more and battery swapping gets harder.
3) I definitely like Tesla's plan though. You can save money by buying a battery that meets 95% of your needs. For most people this will be the smaller ~150 mile pack. When you want to go on a long trip, however, you can simply rent a 300 mile pack for the duration and then swap back to your pack when you get home. That 300 mile pack can be quick charged in around 45 minutes. A typical road trip would have you drive for about 4 hours, then stop for 45 minutes to eat and charge, then drive for another 4 hours and repeat. This is comparable to what most people do with gas cars except that they aren't eating while they fill up.
4) I don't think it makes sense to try to do long road trips with a 100 mile battery pack. That would mean you have to stop nearly every hour to get a new pack. I would think that would get very old, very quickly. Realistically, there would have to be complicated, expensive, battery swapping stations located about every 70 miles to allow for safety margin. That's a lot of sites to get going before you're in business.
5) On the positive side: I'm not concerned about getting a bad battery pack. Each battery pack can have a memory chip in it that tracks its usage. You can know exactly what the condition of the pack is, before agreeing to it. You might even be able to pay for the pack based on the capacity left in it. Through networking, you could probably even know exactly which battery you'd be getting at the next swapping station, before you leave the last one or maybe before you leave on your trip.
6) Battery swapping stations would still require heavy industrial electrical service, even if they don't fast charge. Slow charging 500 to 1000 batteries in a day takes just as much energy as fast charging 500 to 1000 batteries in a day.
7) Building a battery swap station -- ~$5 million. Attendant required
Installing a Fast charging site -- ~$50 - $100 thousand. Self serve
8) Electric Forklift fleets are going away from battery swapping in favor of "opportunity charging" or Fast Charging because battery swapping is such a hassle and "Opportunity Charging" stations can easily be set up in many places around the facility.

· · 6 years ago

Adding to ex-EV1 Driver's concerns, I would also be wondering about potential theft of the battery. If it only takes a few minutes to swap an EV battery pack at a Better Place facility, then it probably wouldn't take all that much longer for a thief on a quiet street with a few tools to do the same . . . but not put a newly recharged battery back.

When I was tooling around in my 1964 VW Beetle a few decades back, I could drop the engine out of that car in less than 15 minutes with an assortment of hand tools, a small hydraulic jack and unadorned (no rim) rubber tire. I'm actually hoping that the battery in tomorrow's EVs won't be all that easy to extract.

And, yes . . . as longer range batteries get developed and fast charging scenarios are refined, I think that the 300+ mile trip with built in charging stops will largely take the place of a proposed large scale battery swapping infrastructure along the nation's highways. Its more efficient to move the electrons via power lines to the charging stations than haul pre-charged battery packs on pallets via 18 wheelers to all those
proposed remote swapping stations.

· · 6 years ago

I have to wonder how much faster or convenient it would be to do a battery swap, versus just using a DC fast charger. Example:

1) Driver pulls into battery swap station, goes to counter and tells attendant he needs a battery swap.
2) Attendant checks stock. Generates swap order on computer.
3) Driver signs for swap order.
4) Attendant moves car into swap bay, or waits until swap bay is clear, if car is already in bay.
5) Attendant gets tractor, goes to warehouse and gets 500 pound battery.
6) Attendant unbolts battery pack from car, including connectors.
7) Attendant uses tractor to remove battery pack, and takes battery pack to warehouse.
8) Attendant removes trickle charger from replacement battery pack, scans bar code on battery pack, and uses tractor to take battery pack to swap bay.
9) Attendant uses tractor to insert battery pack.
10) Attendant bolts new battery pack in.
11) Attendant scans bar code on old battery, and uses tractor to move old battery to warehouse for charging or shipping.
12) Attendant double checks car will start, and checks SOC.
13) Attendant moves car from swap bay (insurance won't allow drivers in bays), to parking lot.
14) Driver signs for battery pack, and pays for pack with credit card.
13) Driver gets back to highway.

If you have ever gone to Jiffy Lube, or to a Smog Station, you realize that things don't always go quite as quickly as they seem they would.

Of course, there are always the usual service issues:

1) "Our computer said we had a battery in stock, but we don't".
2) "We're a little short handed today."
3) "We're having a rush on battery swaps today."
4) "Our insurance company will pay for the damage we did to your car."
5) "Looks like this battery is faulty (after putting it in). We have one at our other location."

Meanwhile, Driver 2 pulls into the self service quick charge station next door. She swipes her credit car, plugs in her car. She sits in his car surfing the web including and responds to email on her car Infotainment system. Before she knows it, 30 minutes has gone by, the full battery alarm sounds, and it is time to leave.

· · 6 years ago

@Benjamin Nead,
The batteries are likely to be swapped by lowering them from under the car. This will require picking the car up. Your thief will have to carry a portable grease rack along. I think it will be much easier to just steal the car. Since the battery is likely to have a memory on it, that would have to be completely erased before it could be sold, which, of course would raise eyebrows.
I'm not too worried.

· · 6 years ago

Most of the scenarios I've seen involve an automated machine in a pit. You drive the car over the pit (Jiffy Lube style). The machine automatically locates the battery and removes the old battery automatically, puts it away, grabs a new one and replaces it. shows a video of the process.
While I'm not very bullish on the idea, it isn't quite as bad as some might fear.

· · 6 years ago

@Benjamin Nead,
I suspect that any battery swapping stations will charge the batteries locally, not try to ship in already-charged batteries. This will allow them to slow-charge the batteries although slow charging a lot of batteries is going to require a huge grid connection, just as a fast charger would.

· · 6 years ago

@ ex-EV1 driver

Well, that IS an impressive video. I do see where this would be a marvelous thing for fleet vehicles and personal EVs in the small, densely populated countries and in larger metro areas, where Better Place is currently setting up their program. I wish them well.

But here we are in the early 21st century, with gasoline cars having been ubiquitous for over 100 years. In certain parts of the US there are still places where gas stations are hundreds of miles apart from each other. It would take a Herculean effort - and matching cost - to deploy swapping stations like this everywhere. Simple charging stations are going to be so much easier and cost effective to establish instead.

Michael's list of "what ifs" is pretty complete, even though the You Tube video may dispel some of the concerns. But while the Better Place facility in (I'll pick a city at random) San Diego will probably have several freshly charged Leaf batteries in stock at any given moment, what about (picking another random city) Cheyenne, Wyoming?

Assuming that there's a facility in Cheyenne, it won't be economically viable to stock enough batteries of any given type there before someone will have to truck one in from Denver, a hundred miles to the south. Thus, one negates many of the environmental benefits of electrified transportation. Heading west on I-80 out of Cheyenne, do you envision a Better Place facility in Laramie, Rawlins, Rock Springs and Evanston . . . before arriving in Salt Lake City?

If the pure electric car is to ever leave the confines of big cities and venture out on the open road, charging stations will what we will be dealing with in the immediate future. The open road EV pioneers will probably use a combination of charging and swapping to traverse long distances. But batteries with greater range and quicker charging potential will be here long before those beautiful battery swap stations appear every 90 miles or so along I-80.

· · 6 years ago


I enjoyed the video.

Once EV models start proliferating, it seems there would need to be some standards for battery dimensions and retention - SAE? - I know a few of you are groaning. :-)

There is also the environment concern of having to produce at least two batteries for every car on the road (assuming battery swapping became commonplace).

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