What's the Ideal EV Battery Size?

[richkae]

Ideal battery size

The ideal EV battery size for most people in the US would be 8 kWhr or less.
That would weigh about 150 pounds, and let you make a super inexpensive lightweight EV ( real car, not a NEV ) with about 40 miles range.
( The entire electric drivetrain including battery would weigh much less than an ICE drivetrain and gas tank )

Replace a little over half the cars ( 100 millionish ) in the US with these cheap short range EVs.
Take a portion of the $400 billion that is spent in the US each year on gasoline, and spend it to install 300 million free EV charging plugs in public places.
Yes 300 million - 3 per car - everywhere that you might go.

Every time you stop your car you plug in and charge. The vast majority of drivers drive less than 40 miles per day, the vast majority of trips is much less than that.
By plugging in everywhere you go, with each stop being a couple of hours, you could comfortably drive this EV around town 100 miles.
These short range EVs could probably drive the majority of the total miles driven in the US by passenger cars and save the majority of that $400 billion spent on gas each year.

*Ideal*

 

[Doug_G]

The 13 miles thing is a red herring. Unless you drive very slowly and carefully the engine is going to kick in.

 

[smorgasbord]

I had mixed feelings about the article, myself. It shows Toyota's mindset, which seems to be, "people don't care about driving electric; they just want to improve the fuel efficiency of their gas-powered car". I think they're missing the whole point of electric vehicles (IMHO), which is to minimize gasoline usage as much as possible -- if not eliminate it altogether.

I think Toyota knows the market really well. For the mainstream minimizing gas usage has advantages over eliminating gas usage. Most people would rather have an ICE in their car than a really big battery. The battery is way more expensive up front and has a more limited life. And then there's the range thing. Most people have at some time or another taken drives of 400 miles in a day, or more. No EV does that today, or only does that with a 3hr break in the middle.

So, the way they look at it, adding a little battery bumps up the gas mileage in a big way and that's both good for the environment and good for their wallet. With a regular Prius getting close to 50mpg, then depending on your daily trip profile, a PI Prius could get you to 75mpg (plus some cheap electricity). That's mighty impressive. But, to go from 75mpg to infinite mpg requires a big change in technology and long trip behavior. Many aren'r ready for that. And, for them it's not about being an EV, it's about saving money and reducing dependence on foreign oil.

That said, I think the Model S will open a lot of eyes.

 

[TEG]

Small battery ends up making more sense as long as the public charging is all slow.
Once we get high speed / fast charging then a bigger battery starts to work.
And we all know that battery prices are dropping.

When I read richkae's comment, I though of iMiev in Japan where they sell it with a small battery, but have CHAdeMO all over the place. Good vision, but the USA PHEV people seem to be holding back the quick chargers which ends up working in their favor.


Also, don't forget if you dump all the ICE related stuff, you save enough $ to put in a much bigger battery. Volt has a much smaller battery than Leaf but costs a bunch more...

 

[doug]

Here's an interesting twist:

EV WORLD: Hybrids: The Best Use for Lithium

http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/52393.pdf

Of course this would only be relevant if there was a scarcity of lithium, which there isn't. But it does support the notion that even a small battery can help displace a lot of gas.

 

[Norbert]

Of course this would only be relevant if there was a scarcity of lithium, which there isn't. But it does support the notion that even a small battery can help displace a lot of gas.

I know what you mean, but feel like adding: It takes 3 times as many cars to displace the same amount of gas (using those numbers).

 

[Norbert]

Plus, when you've replaced all cars with HEVs, you have displaced only a third of the gasoline. So now you still have to sell everyone an EV to displace the remaining 2/3. In the other case, the job is done. So you still need that Lithium... or whatever it will be in the future. So actually, you 'll need additional Lithium to get the job done.

 

[doug]

I know what you mean, but feel like adding: It takes 3 times as many cars to displace the same amount of gas (using those numbers).

True!! I was waiting for someone to pick up on that. The article title is essentially a red herring.

 

[Doug_G]

Irrational. Whoever wrote that needs Lithium.

 

[Norbert]

Irrational. Whoever wrote that needs Lithium.

To be fair, his last slide also contains this sentence:

Li supply does not appear to be a problem given today’s reserve and production
quantities, even under aggressive expectations for EDV deployments

 

[EVFest]

The item has to be thousands of individual tech items. A house has thousands of nails but they don't have the breakdown history of batteries.

However - When was the last time you put the nails in and removed them (1 cycle of use), over and over again, in your house?

 

[Ohm Alone]

I drive an ancient Jetta TDI 300,000 km which has a lifetime of 45+ US mpg, and a Prius C with 52+ ditto. I got the C over the Prius plug in because..11-13 miles?? For an extra $15,000? Shame because if Toyota sold a '21-25 mile on electricity' car for the same price as its competition that gets that EV range, then I would have gotten it in a flash. For me, that would mean almost no more gasoline as I can charge Level 2 for free every 10 miles for 80+% of all my usual and very localized driving. The Volt just uses too way too much gasoline when its off battery, and the Prius plug-in is the only plug-in that offers decent gasoline mileage. So, I guess I wait for a Model III Tesla. Toyota might think they know the market but they ceased to impress me with this and the Mirai.

 

[dhanson865]

Design News - Captain Hybrid - What's the Ideal EV Battery Size?

Watching the recent activity in electric vehicles (EVs) and plug-in hybrids, it's easy to wonder if there's a thread of consistency in all this, particularly in the area of batteries.

Take, for example, the forthcoming Prius Plug-in Hybrid. It employs a relatively small (160kg), 5.2kWh lithium-ion battery. The small battery results in an all-electric range of just 13 miles, but the strategy seems to make sense for consumers who mix regular short trips with occasional longer ones. Automotive industry analysts expect Toyota's strategy to hit a sweet spot with consumers, in part because the small battery translates to lower cost and shorter recharge times.

So the trend is toward smaller batteries, right? Wrong. The Prius plug-in isn't necessarily a harbinger of what's to come.

Just goes to show how "industry analysts" get it wrong.

On the used marked right now I can get a Nissan Leaf with a battery pack that has 4x the capacity of the Plug in Prius (PiP) for half the cost. Used leaf with 10,000 to 20,000 miles on it is about $10,000 in CA, and about $12,000 in other states. A used PiP is well over $20,000.

So end result is when I go to buy a used car spring 2015 I'll be getting a used Leaf, likely a 2011 or 2012 and for half the price it will have 4x the electric range easily (depending on battery degradation I might even get 4.5 times the range should I get a less degraded battery in the used Leaf).

Either the PiP needs to drop in price by a huge chunk or the PiP needs a much higher capacity battery for the same price. It's obvious Toyota doesn't want to do the BEV or serious PHEV thing. The PiP they did make is purely a compliance vehicle for CA and friends. Those of us in flyover country need not apply.

 

[SmartElectric]

The Volt just uses too way too much gasoline when its off battery, and the Prius plug-in is the only plug-in that offers decent gasoline mileage.

The next generation Volt has been more optimized in the gasoline efficiency, and will have more all-electric range. You may not need to wait for the Tesla Model 3.

- - - Updated - - -

when I go to buy a used car spring 2015 I'll be getting a used Leaf, likely a 2011 or 2012 and for half the price it will have 4x the electric range easily (depending on battery degradation I might even get 4.5 times the range should I get a less degraded battery in the used Leaf).

Note that there were substantial improvements made to the Leaf in the 2013 model year, mostly efficiency (heat pump for cabin) and improved ease of use. If your commute is <100km round trip, a 2011 Leaf will likely be able to make it when it's ten years old (6 years from now). If your commute is longer, you may want to review your options on how long to keep the car, or which model year to purchase.