power requirements for xmas lights

I am trying to fix up some xmas lights to run on battery instead of mains. I got 24v of battery together, cut the wires into the controller box so I have some bare ends to feed in to, but when I touch the wire ends together the lights just flash once then off.

OK the back of the "Flasher Unit" says
24v - 50Hz, 1.0A

The 50Hz thing makes me, (electronics skill level: Vandal) think that the supply requires AC not DC.

Is that a reasonable thing to think? and if so, I suspect inside the box this is being converted to DC, as I would be surprised if the LEDs themselves were AC. So, I might be able to solder my batteries in to a different point if I crack the case on the flasher unit?

 

Thanks, I've opened the box and the inputs are labelled AC, I think I can see where this is converted to DC and all I need do is connect my batteries and cut the converter out, should work... in theory.

 

Well, due to general fail, I now see there is a connection between one of the AC in lines and the IC (via a resitor) which I am guessing wildly was used for timing by the IC.