Recharge Batteries in 30 Secs

An anonymous reader writes "NEC has developed organic radical batteries which are recharged in 30 seconds. Good news, they won't (probably) cost more than the current NIMH batteries." Why is it that I'm not holding my breath to have this technology in a laptop?

Comments

Mis-targeted?

[guido1]

The company will initially try to commercialize the technology for using the battery as an emergency power source for computers, according to sources at NEC.

I'm suprised the first thing they're shooting for is the UPS market. I would have thought a bigger market would have been standard-sized batteries (AA, AAA, etc)

The article itself mentions many other uses, including RC cars, digital cameras, etc...

Guess they know their market better than I do.

Conversion ratio?

[TheDigitalOne]

Unless they have a 100% conversion of source electricity to storage these batteries are going to have very limited capacities. Imagine how much heat a 1200mAh battery would give off if only 90% of the charge is actually stored and the rest goes to waste heat during that 30 second charge cycle.

Re:Recharge in 30 sec

[cybermace5]

Actually, being able to drain batteries very quickly is an advantage. Nickel-cadmium batteries are popular in R/C applications because of this. With a lower internal resistance, these batteries will be able to provide a massive jolt of power.

Re:Heat

[lcsjk]

You're right. I should stop there to be funny, but since you mentioned it, the battery heat is due to the internal resistance of the battery. If it is low, the power (current squared times resistance) will be low. Note that the article ended with reference to being able to limit the current from the battery, and that makes me think the internal resistance is low, and therefore, low charge/discharge power for heating.

perhaps you assume too much

[way2trivial]

it does not say it uses electricity to recharge.

perhaps a 30 second recharge means, opening a cap, dumping the contents, and refilling it.. (no heat involved)

note the words organic and resin

You don't have to

[RAMMS EIN]

Well, just because you _can_ charge them in 30 seconds doesn't mean you _have to_.

What about expanding the upper limit?

[Have Blue]

How big are these batteries compared to standard laptop cells? Would it be possible to expand in the other direction, by keeping the charge time around today's levels but greatly increasing the discharge time? I wouldn't mind charging my laptop for the usual 3 or 4 hours if I can use it for a day or more without having to plug in again.

Re:Heat: some real numbers

[zorander]

Well, 30 seconds for a laptop might not be so reasonable, but how about ten minutes? It seems that if the technology is there for such an ultrafast recharge, it should be possible to slow it down (obviously only very special 120VAC outlets in the US will allow you to draw 70 amps). This would knock down our consumption to a much more reasonable 3.5 amps for ten minutes. Still quite a few watts, but not as unreasonable.

Also, laptop batteries have multiple cells. Perhaps they could be charged in series in an ordering such that adjacent batteries were not recharged in direct sequence, spreading the 'hot spots' out over time.

There seem to be a lot of ways to potentially slow down the recharge to make the technology more reasonable/scalable, while still having a relatively fast recharge. I'd love to be able to recharge my laptop in the ten minutes between classes, or go halfway in five. It would extend my percieved battery life incredibly. Getting to an outlet for a few minutes at a time is easy. An hour or two is more difficult, as lecture halls aren't wired.

I like the direction this is going...

Brian

Re:Moore's Law?

[robslimo]

Look again. 2.5V, 3906 W/kg, 20A rated.

And look at this one, 2,600 Farads, 2.5V, 600A rated (not a D cell package though).