I dunno if this has been discussed already but thought I should share anyway. According to Pentax Japan (ist-D FAQ) it uses both in camera and in grip batteries more or less at the same time. In fact it periodicaly checks the voltage of both batteries group and uses the one with higher voltage (or was it current?, not sure...). What it means is this: if your D shows a low battery indicator (and they are low indeed) then BOTH in camera and in grip batteries are depleted.
Hope it helps someone... ---------------------- Thibouille ---------------------- *ist-D,Z1,SFXn,SuperA,KX,MX, P30t and KR-10x ...
