BASF to develop 350-mile e-car 'super battery'

German firm BASF and US company Sion Power have agreed to co-develop a battery technology with the potential to deliver five times the capacity of a conventional lithium-ion battery of the same size. The battery is based on lithium-sulphur chemistry, which Sion’s been tinkering with for some time. Now it's time to take the …

[John Robson]

Batteries are the upgrades

Just define a shape, voltage and socket.

Then sell a car with mostly empty slots for round town, and battery upgrades whenever. In a couple of years when some newfangled technology "batteries" take in air, output roses and power we can simply* slot them in to our existing cars.

* Simply might involve a trip to the garage - but that's not a huge problem...

[Nigel Callaghan]

Still sounds good...

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.

[Adam Foxton]

@Nigel

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.

[Steven Hunter]

Define "charges"

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?

[Eddy Ito]

Finally

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.

[Dave]

@Nigel

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.

[John Robson]

@Dave

The right maths is what he did - a recharge cycle is generally not "any topup" it's generally a full discharge equivalent.

So if I use and recharge 10% each day then in ten days I'll use 1 charge cycle...

Mind you - I reckon I'm becoming clairvoyant: http://www.theregister.co.uk/2009/05/19/lithium_oxygen_stair_battery/

[fishman]

Gas Tax

Since the government puts high taxes on fuel, at some point they will find ways to tax the electric cars electrical usage.

[Kevin]

Umm

I think Nigel was referring if it had close to 0% discharge. Personally I put under 70 miles on my car a week driving to work so if its discharge was close to 0% (impossible I know) I would only have to charge it once every 4-5 weeks. So I would only go through 13 charges tops a year out of 200-250 the battery would potentially last 20 years. So if that was the case 3k would be nothing compared to the amount of gas the car would go through in a similar time. BUT these calculations are in a perfect world with 0% fault and no other factors like humidity etc causing some leakage across terminals and a 100% perfect battery.

[Doug Bostrom]

Another kind of battery

How about a real battery that exists today and will take us 50 miles?

Oops, no patents, no royalties, forget it. We all have to wait...

[Charles Smith]

What about the cables

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.