Hello "BC" welcome in the forum.
This is very strange ... the Merlin head is consuming batteries quite fast but not at this rate.
Are sure that your rechargeable batteries are fully charged ? Do you have a voltmeter to test them ?
If yes, test the batteries one after the other and discard and replace the bad one .
It can happen that you get a problem with one battery in the set of the 8 and if one is defectuous this will block the current of the whole set !
If you have a 12 v cc power supply, you can use it but AFTER removing the internal batteries !!!!
Merlin + Papywizard on Windows 7 & Nokia 770 Â§ N810 & Acer (Netbook) + PanoramaApp AndroÃ¯d + Deltawave PapyMerlin BT + Autopano
Spherical Pano (180 x 360) with Canon 40D + Canon EF-S 10-22mm f/3.5-4.5 Zoom & PÃ´le Pano with Canon 5D MK2 and shaved Tokina 10-17 3.5-4.5 AF DX Fisheye
Gigapixel photography with Nikon D200 + Sigma 70-200 F 2.8 EX DG APO HSM