What size lithium battery?

[Salmonslapper]

Hello everyone! New to using a fish hawk! What size lithium battery should i buy? 12v 50ah or should i buy a 12v 100ah? Normally on the lake 8 to 12 hours trolling. Thank you in advance!!!!!!

Edited May 22, 2025 by Salmonslapper

[AnglingAddict]

Are you just going to run your fishhawk straight off of a dedicated battery?   Most folks wire them into their DC system - its not so much the battery capacity you need to worry about its whether or not your charging system on your boat can keep up with everything else running.  Without knowing exactly what you are doing and the rest of your setup its hard to say.   If you are planning to just wire it direct to a lithium battery that isn't connected to anything then see how much current draw the unit has and multiply that by 8 hours if that's how long you plan to trol and that's the number of amp hours of capacity you will roughly need - multiply that by 2 to ensure you have a little buffer.  

Edited May 22, 2025 by AnglingAddict

[Salmonslapper]

Sorry about that! The plan is to run it directly to its own dedicated battery.

[SusanJames]

I believe the Fish Hawk draws about 2.5 - 3amps when running so 2.5 X 8hrs = 20ah. Like AnglingAddict said, double that and you will have a buffer. I would think a 50ah Lithium would easily last for 8hrs.

[HB2]

Out of curiosity , why the separate battery and not your main battery ? 

[Salmonslapper]

Its an outboard motor and im already running the boat , fish finder and two down riggers off it.

[rolmops]

45 minutes ago, HB2 said:

Out of curiosity , why the separate battery and not your main battery ? 

I'm curious as well, I troll for eight hours at a time and the kicker provides plenty of power, so it does not drain the battery at all.

[HB2]

I have kicker also and run everything off my battery, no problems  .put a noise filter on your kicker for better performance  with  all your electronics . Got mine from Kell Industries where I got my Depth Raider . Game changer . 

Edited May 22, 2025 by HB2

[Yankee Troller]

I ran 2 10" HELIX's, 2 cannon downriggers, a fish hawk, and fm radio off the cranking battery while the kicker was running. You should be fine.

 

The right way to do it is to add a house battery (I couldn't do that becasue my main engine was a 2 stroke and there was an oil tank so no room for a 2nd battery). Blue Sea Systems sells an "Add a Battery" kit. Follow the directions and it's easy to install (make sure you use the appropriate sized wire). The relay will close and send a charge to the house battery (that will be running all your fishing equipment) when it senses a charge from the engines alternator. When it doesn't sense that charge it opens and your cranking battery doesn't get drawn down by those electronics. Any questions call me at Krenzer Marine, or drop a DM.