Even if they can't seriously improve the battery life, it's still pretty good. Do the maths: 200 charges for 350 miles each = 70,000 miles, or about 6 years for average annual mileage before replacing. 70,000 miles in my diesel Punto currently costs me about £6000 in fuel - so if they can do a battery that lasts for 70K miles and costs say £3K they're still onto a winner.

Not sure about that- if I was given the choice of however much a month being spent in petrol or a lump sum spend of £3k I know which I'd take!

I guess a special low/zero interest loan could be created to fund it or something.

Whatever happens, remember the old-car market. My car cost under £1k. I wouldn't want to lash out £3k for a new battery. So the "used" value of a car with minimal charges left plummets, and the minimum cost of a car that'll last a year hovers around the £3k mark.

Is that 200 full discharge-recharge cycles? What if I plug in every night when I get home after draining the battery by half? Will that shorten or prolong the life?

Charge cycles aren't really a problem as long as it doesn't have a horrid self discharge rate. Compared to the other lithium rechargeable batteries it still seems to have twice the capacity. The expected lifetime, in charge cycle count, of current Li-xxx is roughly 1200 cycles with an energy density, being generous, of 200 Wh/kg. This gives a lifetime energy density of 240,000 Wh*cycles/kg. The Li-S tech would seem to have a favorable 390,000 - 520,000 Wh*cycles/kg. By all means, if the volume of a comparable battery isn't the size of a bulgarian airbag, start by bringing on the Li-S batteries for my cell phone. I'll be happy to beta test, going from a recharge every few days to every few weeks or a month, 100 cycles would still give me several years of service before I'd need to replace it.

Now if we could just get around the regulators holding it up in "safety trials" for years we'd be well on our way to e-cars and e-supercars. Even ones with silly, and did I mention soon to be broken, air brake spoileron flapper things running in LeMans.

Try doing the _right_ maths:

200 charges max, for 350 miles max does not compare with a liquid-fuelled vehicle that has the same performance whether it has 1 litre of fuel, or 45 litres on board.

Lets be charitable, and assume that with normal usage, you can get 250 charges, but on a normal commuter cycle of 30miles per day. Lets double that, just to be nice (assuming a few big journeys from time to time) giving 250 times 60 = 15,000 miles, which is not an awful lot more than average yearly mileage.

Alternatively: circa 200 working days in a year, recharge the battery every night, let me see... about one year before the battery is worn out.

Now you need to factor in the recharge costs, before comparing list prices.

Only townies will understand this one:

Won't it be a bit dangerous having the streets filled at night with cables stretched across pavement (sidewalks) from the front of your house to the car parked in the street.