Hello anu25,
The specifications of the DAQPad-6052E manual state that it can take 9-24 VDC and requires 20 Watts of power (see page 14 of the specifications manual linked below).
NI 6052E Family Specifications
http://digital.ni.com/manuals.nsf/websearch/EAA4406C446E621B86256DA20074054C?OpenDocument&node=10931_US
So, if the 12 V battery can supply enough power, it should work for you.
There is a battery pack and 120 VAC charger option for the DAQPad-6052E that would be an alternative as well.
NI DAQPad-6052E for FireWire
http://sine.ni.com/apps/we/nioc.vp?cid=10931〈=US
I hope this helps. Let me know if you have any additional questions.
Regards,
Todd D.
NI Applications Engineer