Hi guys, We have a 7 week old child and she will only really sleep in a battery operated rocker... it takes 4 x D size batteries. it's costing us a absolute fortune in batteries. if i was to connect a plug like a laptop power socket to the battery terminals. what voltage power brick would i need to keep it powered and not blow it up ? the batteries are 1.5v and there's 4 so does that mean i need 6V to run it ? have one of those adjustable power bricks and the right socket.. just need to know the right voltage Cheers !