Battery powered DAC

Not positive but from a more detailed analysis of the wiring it appears the board requires 24 V . In the charge position the 2 reds and the 2 blacks have the 12 v applied to them to the 2 separate batteries which must be 12v each and assume the caps are put across the terminals as some kind of snubbing ?. When in the run position the batteries are put in series to the board with the floating ground to the board connected to the red of one battery and the 'ground' of the other. Maybe someone can confirm this before I proceed. Tnx .

Hey all. I know this is an ancient thread but I obtained an original Ack! with no batteries. Just wondering if I can use a single small lead acid 12 volt battery. There are four leads from the connector, 2 reds with caps and the 2 black wires. Looked at the 3PDT, 12 pole switch and it’s a little confusing . One red lead goes to the red wire to the board while the other red goes to what appears to be the ground plane, a green wire. which is jumpered to the associated black wire from the battery harness . The other black wire goes to the black wire to the board jumpered with a cap. I never saw the original batteries so don’t know if they were 6 volts each in series which I would think would only need 2 wires to the switch or 2 12 volt.in parallel. Also thinking of using a larger external battery or a lab grade external power supply. Any knowledge would be appriciated. BTW I didn't want to spring the over $130 Can for the battery pack from Ack .