With this capacity and weight, I come up with 973 lbs for a 24 KW battery such as in the Nissan Leaf. Am I wrong? Here's my calculation:
5 amp x 3.5 volts = 17.5 watts
24 kw divided by 17.5 = 1371 batteries
1371 x 318 grams = 435978
43978 divided by 28 = 15570 ounces
15570 divided by 15 = 973 lbs.

That is only about 55Wh/kg. There are supercaps under testing that are over 20Wh/kg and they will provide much more power (and there are some new experimental supercaps that may top out over 60Wh/kg themselves).

I think that it would be better to focus on supercaps to supplement the batteries in this type of scenario. They have hundreds of thousands or even millions of cycles compared to a few hundred or possible a few thousand cycles for most batteries.

But any battery research seems useful and maybe there will be some cases where these batteries would have an advantage...certainly price wise they could at this point.

DaveD has a very good point. Super caps (specially future ones) could be a better solution then these very low energy density batteries.

@ DaveD and HarveyD,

I like supercaps very much for storing 30 seconds worth of hard acceleration, to supplement batteries in HEV...but even that small amount seems to run about $1,000-$2,000 (from Maxwell), before you get to the batteries and control electronics. Has anybody else run numbers that differed much?

High energy density ESStor units will be out soon and we will change our appreciation of what super caps can do. One storage unit may be enough for 30+ years or your next three vehicles.

A 50+ Kwh unit, recharged every night at low over night rates, could supply all the energy required for the house + 2 BEVs. Power grid peak loads may be eliminated or better managed with automated charger controls.

@ Reel$$,

I don't think your premise leads to your conclusion.

If energy companies get so much demand from BEV that they raise night-time electricity prices, we still come out way ahead as a nation because:
1. Power plants are about twice as efficient at getting energy out of fossil fuels as ICE cars are, which cuts fossil fuels for vehicles in half, and;
2. We could then power some of our vehicle fleet with indigenous coal reserves, which helps greatly with energy independence and still emits less greenhouse gas than petrol, and;
3. Renewable energy sources will gradually increase their share of the electricity market, further helping energy independence and CO2 emissions

@ HealthyBreeze; danm; Reel$ Yah, and I would contribute that off-grid production outside of legacy-urbanized areas is an open (sh-h-h-) gift waiting to be exploited by individuals/groups desiring a community-run and administered grid for charging their vehicles, powering their homes, etc.

@HB:

Correct that EVs powered by old grid DO lower demand for imported oil and therefor are a boon to energy independence. I am pushing CHP not only for efficiency and independence - but for other myriad benefits.

1) JOBS - manufacture, installation and maintenance of CHP systems invigorates an entire new energy market.

2) Limits or excludes need for new coal-fired power plants - an environmental boon.

3) Security - centralized grid systems are easy targets and subject to climate/exposure related failures.

4) Economics - we've had a century of high voltage copper wire strung overhead. It is hazardous, costly to maintain, inefficient and unsightly. Distributed energy lowers grid demand and competes at $/kWh.

5) Politically there is danger in handing energy management from oilcos to electric utils. Most utils are public/private State or Municipal entities incorporated to produce profits and dividends. Presently they monopolize the electric energy markets - city dwellers and rural home owners have a single choice for electric power. Prudent business demonstrates the danger in single-source supplies. Competition from CHP systems pressures utils to better SERVE their energy market and customers.

It is rapidly becoming feasible to make our own power, heat and cooling without need for a grid - "smart" or otherwise. Let's create JOBS, become truly independent, enhance security, obviate overhead wiring, limit new power plant demand and...!! green the world!

Energy independence is evolutionary.

Most utils are public/private State or Municipal entities incorporated to produce profits and dividends. Presently they monopolize the electric energy markets - city dwellers and rural home owners have a single choice for electric power. Prudent business demonstrates the danger of single-source supplies.

It's worth looking at magnitude of change required to replace oil imports by various means. If the entire ground transportation system was converted to electricity, it would cut demand by ~12 million bbl/day and imports by perhaps 75%. The increase in electric demand would be approximately 40% over today's average (making conservative assumptions). To produce 12 million bbl/day of new crude would require an increase in domestic production of more than 200%. Electrification can get rid of oil imports, "drill baby drill" can't.

It was estimated that a 100 mile by 100 mile area in Nevada could power the whole U.S. I calculated that it would cost more than $12 trillion, or the whole U.S. GDP but the fact is, it could be done.

This is the nature of going down one path for 100 years with no alternatives. The investment is made over the long haul and to make changes later in the game becomes more expensive. Let us hope we find the way to make more of the transitions that we require.