sonar and 36 volt trolling motor

[river rat316]

I have a ? I am re rigging my front bow depthfinder, and want to run it off my trolling motor batteries (since there also upfront) but I am running a 36 volt trolling motor, and was wondering if there was a way to just draw off of one battery for the 12 volt depth finder? Or am I gonna have to run a wire all the way to back ( I currently tapped into the front light, but I seem to lose power after 5 minutes of having the depthfinder on) I dont know if I am drawing enough from the lights skinny wiring

[Capt. Don*]

Look at the specs on your bottom machine, alot of newer high end machines are capable of a wide supply voltage spread. If yours will handle between 12 and 36 volts just run it from your trolling motor batteries. One of my larger boats still uses a 32 volt system and the elctronics will work at 32 volts just as they would at 12 volts. If your machine will not accept 36 volts, don't try it, run a 12 volt supply from your starting battery.

[katoguy]

You can tap in to just one of the trolling motor batteries to get only 12-volts. However, you may get interference on your depth sounder screen. It is recommended to supply power to your depth finder from your crank battery.