Just in case anyone else is interested...
I want to be able to use my Scroll extreme when I go on holiday to Cyprus later this year (keep the kids entertained, watch movies, play games, etc). It is quite a long flight (5 hours), plus all the time hanging around in the airport, so I was looking at possible battery "top-up" options. Although it states in the manual that you should not charge the device with anything other than the supplied adapter, I fugured that if you can trickle charge from a PC/laptop whilst syncing (via the micro USB port), any USB power supply should be ok (it is a global standard after all). I tested it last night from a USB mains adapter and it charged the tablet just fine (no fried tablet, which was a bonus ), so got myself one of these http://www.ebay.co.uk/itm/160692696987?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
The added bonus with the micro USB socket trickle chage option is that I can charge the device in the car from an aux power supply (cig lighter) USB plug, and if the supplied power adapter gets lost or broken, I have a backup. Should work fine I recon