Can you wire a sonar to a trolling motor battery?

[Erie660]

I know this is not recommended because of interference but has anyone ever done it? My 3 - 100 ah lithium trolling motor batteries are under my rod locker in the bow of my boat. This is a 36v setup, but is it possible to run wiring to my bow sonar off of one of the 100 ah lithium batteries? I need to run some dedicated wiring from my cranking battery to my bow because I’m experiencing some voltage drop so I’m just wondering if this idea is possible. My console electronics are fine but my bow unit is the one that needs rewired. Thanks

[5keepers2]

Sure you can do it but I would not and most will tell you not to!

[CatFan]

Yes, but you don't want to.

[yam911]

Only way to know if it will work for you is to give it a go. Try it and see.

I would wire it up on a temporary basis. If it works then I would proceed to do a complete final installation.

Please report back.

[bobcoy]

You would be hooking up direct to the trolling motor source for electrical interference. Not good

[KJINTF]

Yes you can, however as others have said there MIGHT be electrical interference on the graphs from the trolling motor
Me, I have never experienced any interference or any down side to doing just that - no way to get another battery in my 17ft boat (2 - 100amp Ionic, 1 - FLA starting battery)
The 2 Ionic 100amp batteries power my Ulterra 80. I tap off one of them to power several other devices including but not limited to: My graphs (2 helix units), Stereo, Inverter, Live wells, lighting, 360, Ethernet switch, NEMA network, etc..
Never any issues with the electrical setup no electrical interference from any source or any other power issues this system has been in operation for 2 plus years now and works for me
The engine FLA battery can be remotely connected in parallel to the Ionic battery that supplies the several loads - I did this because my Yamaha F90 R/R system is pathectic at best

[bobcoy]

Do you have a common ground between the starter bat and TM bats?
I am interested in your wiring scheme. How does the inverter connect to the system?

[KJINTF]

bobcoy, regarding your questions
Since the 2 Ionics are in series the only common ground or battery "-" is between the engine FLA battery and a single Ionic battery - simply answer yes both batteries "-" terminals are connected to the metal hull and each other
I copied my RV electrical system to the boat to keep things simple for me - I have problem with CRS sometimes - there is a 200amp 100% DC contactor that can be commanded to parallel the engine and a single Ionic battery
The inverter is a PSW 1Kw with a switcthed Blue seas 80amp breaker off the Ionic battery. The inverter gets us 120VAC as needed for blenders, etc. Nice when camping to have another source of 120Vac

[bobcoy]

Very interesting. Quite a rig!