I have a 1994 25 Dolphin with 03 FS225s. I am in the market for new electronics. I want to purchase the multifuncition display units with open array radar and chartplotter and depth/fish finder. I have not made a decision as to what brand I am going to go with. This is my question I have 2 batteries and 2 switches. I have heard that these MFDs with radar use alot of juice. Should I go for 4 batteries and 2 switches? and if I do is it a major electrical issue? Will I benifit from it? Is this the right thing to do? I have a feeling that the sales staff at my local marine store will sell anything to make a sale. Thank you to any one that replys