Sorry but that doesn't do it. If you plug it into a PC and set it for Charge Only, the SD card is STILL taken offline ???? Look in Settings, etc. when it is Charge Only.
This is a PITA because my HTC charger won't fully charge the HTC (stock) 2150mAH battery I have, and if it's low, the little HTC charger won't even light the charge light. So I'm stuck using a powered USB hub on my PC... and all sorts of stupid stuff happens when the SD card is offline.