Frist of all I would like to thank ever one for the fedback on the OpenROV site. I have desided to go with the battery on board, to power everthing. This ROV will be used in are summer camp at the Marine Science Center at Ponce Inlet Florida. Kids in middle school will be setting the ROV up and running it, of course under supervision with a camp leader. I realy did not want to have an open battery. The ROV will be stored in a case along with a detachable tether and LED monitor. We wanted ever thing to be portable as one unit and easily carried. Now to get down to the chase, should there be any typ of electronics between the battery and the relay connections? If their is any advise out there on this set up, please fill free to advise me. We want the chrildren to have fun and learn in a safe environment.