Adding a battery?

[Carl1969]

My little boat came set up with a 30lb trolling motor running off the starting battery. I'm sure that may be okay for a few minutes here & there, but I need to power a fish finder as well & don't think that's gonna cut it. What's the simplest, no hassle way to add a deep cycle battery to run the trolling motor & fish finder? Is it as simple as picking up a decent battery & an "Add a Battery" kit? I'm assuming I'll have to spring for cables & know I'll need a marine battery box.

How do I know what size to get? 24, 27, 29? Or do I just go for the most reserve capacity I can afford? I'm buying a Noco jump box to keep in the boat, so can't imagine I'd ever need the deep cycle as a backup starter battery. I would like to upgrade to a bow mount, foot control 45lb trolling motor at some point, so something that can handle that & the Garmin.

Mounting location? Starting battery is in the port rear corner, with a 6 gal gas tank starboard. Maybe mount the deep cycle starboard rear & place the gas tank between the batteries? There's room & I'm thinking it'd be balanced side to side. 

What say ye?

 

[fishinwrench]

Unless you're planning to run FFS (Livescope)  a single Exide Nautilus 27 MDP  (Marine dual-purpose) will power it all, and last through 2 days of pretty hard core fishing. 

My jonboat rig has one, and it provides starting power for a 35hp outboard, a 12v 50# MK Power drive trolling motor, Lowrance X5 LCR, a livewell pump, bilge pump, and navigation lights.   

Typically after a reasonably hard day of fishing I still have 70% charge remaining.  

[fshndoug]

Glen's boat uses more power to haul all my tackle around.

[Dutch]

You will get less interference on your sonar if you power it from the starting battery instead of the trolling motor battery.

[Carl1969]

Sweet. Thanks fellas.

 

[fishinwrench]

If you are currently not experiencing troubling interference then you won't get any more by changing the battery.