Anyone had one? My uncle has the one without down imaging and loves it. I was really just curious if I need a separate battery for a fish finder or if I can just hook it to my regular battery. 

Skip the down imaging and get the regular piranha max, I had one and never used the down imaging. The 2d sonar shows enough detail that I could find fish and figure out what type of structure was on the bottom without the down imaging. You need a bigger display with more pixels and a stronger unit if you want down imaging to be useful.  It's a nice fish finder for the money, but I quickly upgraded to a helix 5 when I found one for a good price. The Piranha max also uses close to zero power, I think it's only 250 milliamps 

Yes you need an extra battery

I already have two batteries. do I really need 3 batteries on my boat?

 

thanks for the tip on the down imaging. Ill just get the regular one, i figured for $40 more it couldnt hurt to get the down imaging.

My personal experience is having sonar on starting battery and trolling motor definitely on its own deep cycle battery. Though, I typically turn off sonar once I am on a spot.  Realistically my Lowrance Elite 5 HDI does not consume too much.  Good luck.

You'll be fine hooking it up to your starting battery. If you put it on your tm battery, you'll most likely have issues with interference.  

I was just going to hook it to my starting battery. I wasnt sure why I kept seeing batteries for depth finders and wanted to make sure I didnt need one.

Common sense use of Down Imaging helps interpret what regular 2D sonar is showing.

 

Notice any difference between DI and 2D in these brush pile screen shots with both?

 

 

 

How about the difference in the way this tree is represented with both technologies?

 

 

 

I can see where it would be beneficial. which depth finder are you using?

25 minutes ago, Mason_tay said:

I can see where it would be beneficial. which depth finder are you using?

 

 

All my units are Humminbird Side Imaging.