we need more power

According to the Celestron CPC 1100 user guide, the power supply requirements are as follows...

12 VDC nominal
15 VDC maximum
9 VDC minimum
centre tip positive
1.5 amperes

That's according to the April 2005 and August 2009 editions...

The official "standard" supply you can order from Celestron is rated at 2.5A. They also sell a "heavy duty" supply that puts out 5A.

There it is...