Mounting a Humminbird 859ci HD combo on bow

My dad and I recently purchased a 2009 Carolina Skiff 178dlv. Today I will be mounting a Minnkota Terrova 80# thrust 24v, with universal sonar 2 and iLink. I will also be mounting the hummingbird 859 on the bow. I am trying to determine what is the best way to mount the depth finder. I will have 2 batteries at the bow, but they will be connected together to make it 24 V. I need to figure out how to power the depth finder. At least I don't have to worry about the transducer because it will be connected to the universal sonar. Any advice is appreciated.

Also, what would be the best batteries to use for the trolling motor?

Run the sonar off of your cranking battery. You can get 12 V by using just one of the trolling batteries, but you would probably get noise when the TM is running, so use the cranking battery because it's not in use when you are fishing

:hesaid