Sl-5500 Power Questions Options

[Storm]

Sorry for the crosspost, I got to thinking on the drive home that this topic would probably be better off here than the OZ forums...

Got a question regarding the charging subsystem on my SL-5500. My daughter's puppy chewed up the end of the charging brick. I have a USB cable charger for use in the car. Since I don't yet have another brick, plugged this cable into a USB port on my desktop machine, and the yellow light came on. I came back down the next morning, and the light was off, which I thought indicated a full charge. But come to find out, the battery was dead. I brought it in to work, where I have another cradle/brick and it charged up. I've always had pretty good luck with it in the car, but I always had a charger to plug it in to. Is there something odd about the charging on the USB side that would drain the battery competely overnight?

Also, I know the power system is the same voltage and similar amperage as the Playstation Portable. I remember a thread saying that you could use the power bricks as an emergency power source for the Zaurus about a year ago. Does the same apply to the AC adapter? Has anyone tried it? I searched the forums and see kind of mixed results and none are specific to the SL-5500. I looked out on ebay and couldn't find anyone selling the power brick...

Thanks,
--Storm