anyone with a 788ci

are they only compatible with 12/24 battery set ups? still having problems and this is my last troubleshoot before i send it back. if it is only for the 12/24set ups, i might have mine for sale real soon, unless humminbird would be willing to take it back. ive looked in the manual and im not seeing anything about this.

nevermind, i think i found what i was looking for. it says the control head must be connected to a 12 VDC power supply. i dont have a 12/24 set up so i think that answers my question.