Wiring in multiple depth finders and trolling motor

[Bdnoble84]

I bout a second depth finder (reveal 5 SS) so I can have bow and transom depth finders. I also have a 50lb transom tm on the bow. I have always ran tm and depthfinder off same battery. If I add another depthfinder to the battery Am I going to cause issues? I have heard that running two depthfinders off same battery can cause issues. 
space is a premium for me since its a small 14ft alumicraft. 

[gunsinger]

I run both my finders off the same battery and am not aware of any issues.

[Scott F]

I’m curious as to how you put a transom mount TM on the bow. You’ll have more issues running the TM and depth finders off the same battery than you would running two depth finders on one battery. If you have the option with your units, switch the sonar frequency on one of them so they don’t interfere with each other. 

[Bdnoble84]

Made a wooden one. Dont have a great picture. I want to make a metal plate for it. It has more flex than I like.

[DaubsNU1]

I used marine grade plywood, and reinforced with aluminum angle iron for my bow mounted TM. Also screwed to the boat around perimeter. 

 

One battery for the trolling motor, a separate battery for the fish finders, bilge, lighting.

 

 

 

[Jig Man]

You are more likely to have issues caused by the trolling motor than the two depth finders.  I have had as many as 3 units on the same battery with no interference.  
 

Your units might “cross talk” if their sonar cones overlap. 

[TnRiver46]

1 hour ago, Scott F said:

I’m curious as to how you put a transom mount TM on the bow. You’ll have more issues running the TM and depth finders off the same battery than you would running two depth finders on one battery. If you have the option with your units, switch the sonar frequency on one of them so they don’t interfere with each other. 

You can also take the head loose and re install it for mounting transom mount on the bow 

[Bdnoble84]

32 minutes ago, TnRiver46 said:

You can also take the head loose and re install it for mounting transom mount on the bow 

Exactly what I did so I dont have to run in reverse.

[S Hovanec]

I'm running 3 sonars on the same battery.  Your issues will come from the motor on the same battery as the sonars.

[Bdnoble84]

What would you all suggest for a battery just for the depthfinders considering space and wieght are a concern for me?

[MN Fisher]

13 minutes ago, Bdnoble84 said:

What would you all suggest for a battery just for the depthfinders considering space and wieght are a concern for me?

Get the stats for the finders - you want to know the current draw...usually in AMPS

 

Add them together and multiply that by the number of hours you expect to be out.

 

If you get a flooded battery (sealed or not) - multiply by 2

If you get an AGM battery - multiply by 1.4

If you go Lithium - multiply by 1.1

 

That gives you number of Amp-Hours (AH) you want.

 

From there, it's up to you - Duracell, Optima, Mighty Max...all are good batteries.

[HenryPF]

On 8/24/2021 at 3:41 PM, Bdnoble84 said:

What would you all suggest for a battery just for the depthfinders considering space and wieght are a concern for me?

 

Got Milwaukee or DeWalt power tools with a few batteries sitting around? Doesn't require on board adapter, super light, etc.

 

 

 

 

[Bdnoble84]

For a depth finder and trolling motor hooked on the same battery, is the negative effect only seen when they are both running, or does just having them hooked to the same battery cause the issue

[MN Fisher]

1 hour ago, Bdnoble84 said:

For a depth finder and trolling motor hooked on the same battery, is the negative effect only seen when they are both running, or does just having them hooked to the same battery cause the issue

I ran my Endura-30 and my Garmin Striker off the same battery - with a proper filter in the Sonar power line. I saw no negative effects on the Sonar even while running at speed-5 on my MinnKota.

[WRB]

As long as your have minimum of 12VDC with the TM running the sonar units should OK. If the TM has digital pulse it needs to be filtered for a clean power source.

If your OB has a alternator that provides charging power, you need separate batteries.

Small sonar units don’t use a lot of amp draw and small 35-55AH battery for the sonar resolves any TM  interference.

Tom