> > That's not a bad idea, you should go make some. > > ok, i hereby patent the idea! Something along these line: They pop up every so often, usually for phones. This one is interesting as it only has 2xAA batteries, meaning there's a boost converter in there somewhere. I've seen other iPod thingies that have 4xAA. It also shrinks, I had a mains charger once that did that. Handy for travel. That's why I got that little Rezap charger, do AA cells for a camera etc. Finding a USB port for power isn't hard. I had a quick look inside it and wasn't impressed. The only IC I could see was a 4060, a 14 bit timer. So the charge algorithm is probably 'run-for-10-hours-then-stop'. Explains the AA-AAA switch, just halve the time for AAA. Still, it's small & light. So a case with few NiHM cells, you'll probably need a boost circuit in there somewhere, USB-B on one side, USB-A on the other. Throw in a USB A-B cable, PC-to-pack for charging, pack-to-device (mini-B might be better) to run it. Or just plug the device straight to the USB-A. Just like $deity intended. Could be handy, now when camping you don't need to lug your laptop along to power your USB toothbrush, the battery pack should keep it running for a few days. 2500mAh cells, given USB is max 500mA per port, that's say 4 hours and up run time. Not bad. Huh, I should make one before your patent comes thru :) You can now get car adapters, a cigarette lighter plug with a USB port, or a wall wart with no cable, just a USB socket. I like it, one wall wart for any device. And I found you can get USB A-A cables locally. . Why'd you'd want such an abomination is beyond me, and you get to pay double the price. (I'm happy with that's how it was done before USB-B was invented.) Tony -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist