Quoted from Imaging-Resource DPS-9000 Review
http://www.imaging-resource.com/ACCS/DPS9000/DPS9000.HTM
"I know from past experience that some high power-drain cameras are problematic when used with external battery packs, even when the voltage rating of the pack and the camera's input spec seem to be compatible. A case in point is the Minolta Dimage 7/7i. That camera shows a voltage spec on its external power jack of 6.5 volts, but I've found in the past that it required a LiIon pack with an 8.4 volt output to power it properly. I happened to have a Dimage 7 on hand, waiting for me to take a look at the latest firmware upgrade from Minolta.
I've used this camera successfully with Maha's LiIon "PowerBank" external battery pack with good results, but when I plugged the D7 into the DPS-9000, it wouldn't power up properly. - The camera turned on, but the rear panel LCD wouldn't light up. Switching to the D7's electronic viewfinder (which has a lower power drain), the camera worked normally. I could even snap photos with the rear panel LCD enabled, I just couldn't see what I was doing.
The Dimage 7 and 7i are particularly demanding cameras from a power standpoint, so my experience with the D7 may very well be unique to that model. (It doesn't even seem to be a matter of the pack's ability to handle high power drains, but may possibly be an issue with noise voltages appearing in response to large, short spikes in current demand when the LCD backlight tries to start up.) Still, it does appear that you should actually test the DPS-9000 with a camera, if you suspect it has a very high power drain."