Rupert Goodwins' Diary

Thursday 21/09/2006

Now, here's the silliest idea I've seen all year. OK, perhaps not quite as silly as Zune's DRM, but still silly enough to feed a family of four for a week on prime stupid with enough ridiculousness left over to repaper the spare room. USB batteries.

On the face of it, it's not such a bad idea. Pop the top off an AA cell, there's a USB plug, shove it in a nearby socket and let the thing recharge. The USB standard is enjoying an unexpected secondary life as a universal low voltage power supply, and it's generally a good thing if your mobile phone, camera or PDA can recharge itself from a nearby computer. Who wants to have to loft around an extra charger?

The trouble is in the details. First, the extra space needed in the batteries for the connector and the individual charging circuit takes up so much room there's not much left for, well, the battery bit. Each battery has around half the capacity of the best standard AA rechargeable, meaning you'll have to charge it twice as often. If your AA-powered device can run for a day between charges on the full-fat batteries, as most can these days, then you're gaining nothing but inconvenience.

Then there's the small matter of them being quite fat. Most multiple USB sockets I know are close together, designed to let you stack those thin USB leads without wasting space. That means there may be two sockets, but only room for one battery — and even that's blocking the other port so you can't plug anything else in either. And how on earth are you expected to charge four at once, which is by no means an unusual requirement? A hub, perhaps, but then it would need to be powered — which rather takes away the point.

Also, they don't charge very quickly. The most you can get out of a USB socket is 500milliamps, which means they won't get to full charge in under three hours. A decent fast charger these days can wallop much more capacious cells into shape in half that time, and there are various superfast variants that get their fill in 10 minutes.

Finally, the cost. At 13 quid for two, you're paying four times the price per milliamp hour as you get from buying top-capacity standard batteries. In other words, for the same price you can spend four times as long away from the charger. I'd consider not having to charge them up much more convenient than being able to stuff the things into a nearby computer.

There will be some people for whom this is a godsend. But I can't think who they might be, and I can't imagine there'll be many of them. However, there will be many more who think "What a bright idea", dash out, buy a set, use them twice and then let them decay in a desk drawer somewhere thereafter. I know this, because every other gadget blog and reviewer I've read has had to call for new underwear after extolling the sheer genius of the concept.

They're all wrong. I alone am right. Just you wait and see.