New Fish Finders and Battery Draw?

[1Cast 1Fish]

I took the plunge on Black Friday and decided to update my electronics on my boat (they are about 10 years old). I am a bit concerned after reading hear about how many are running dedicated electronics batteries for their sonar units.
Here is my current setup, and it runs with no issues.
Console: Humminbird 1198C SI & DI
Bow: Humminbird 788 Ci HD

Cranking Battery: Interstate 27M-XHD ... Everything is running from my Cranking Battery currently, Sonars, Livewell, Radio, Lights, ect

I bought 3 New Garmin 106 SV's from Bass Pro, I intend to use 2 on the Console, and 1 at the Bow. I do not have any need or want for liveScope at this time.
New Setup
Console: 2 Garmin 106 SV's with GT36 & GT15(In Hull)
Bow: 1 Garmin 106 SV with GT 54 on Trolling Motor
All Units will ne Networked together.

Before I get started with installing everything, I wanted some opinions on power draw and if I should be good with my current battery. Anyone else running 3 Sonars with the Cranking battery?

[gambler1]

Amp hours on your battery and load draw will give you an approximate run time of juice.
Thats a big demand for a single battery.
Group 27 is a lot less than I would be comfortable with. Group 31 at minimum.

[Bill Reynolds]

The attached chart is fromAmped outdoors and shows run time on different sized Lithium batteries. The part you are interested in is the amp draw on each unit (2.8) so you are looking at 8.4 amps, that’s a lot. For the net affect you would subtract the amp draw from your existing units but I don’t know that number.
I also don’t know Watt hours for a group 27 lead acid battery, hopefully one of the smarter guys will weigh in.
That being said, I think you will need a bigger battery.

[pm0084]

Yeah I was pretty afraid that I was going to have some power issues after looking up my current fishfinders and their draw, about 2 amps and 1.7 amp for the Humminbirds, so switching to the Garmins at about 3 amps each, I definitely will be loading it down.
So I have been trying to find the best economical solution that gives me some flexibility.

I honestly do not have room for another full size battery, and even so switching to a dedicated electronics lithium will be expensive for the size I would need for a full day fishing. So here is what I am thinking

I have a 36V Terrova Trolling Motor that is 10 years old as well, I run it off 3 Interstate Group 31 Deep Cycle batteries (Which are all new this summer) They rate at about 100 Amp Hours. If I was to bite the bullet and upgrade to a Garmin Force Trolling Motor and run it at 24V, which they say is as powerful as my current 36V setup...that would free up a Group 31 Deep Cycle. I could then run all 3 fishfinders and possible LS later off this single battery as a stand alone electronics battery.

[MonteSS]

The 106sv draw about 2a each My Lithium has an App that tells all functions of the battery and draws). Run the bow one off the current starter battery and run the two console off a dedicated small and light 30-50ah Lithium. Cost you $200-300 and you will be good all day.

Or a 31AGM starter might do it all (about $400)

[Impulse Lithium]

Check out our 12v-100Ah ALL PURPOSE Lithium Cranker, will give you performance all day with this setup

https://www.impulselithium.com/product/12v-100ah-all-purpose-heated-lithium-battery/

[Bill Reynolds]

Yeah I was pretty afraid that I was going to have some power issues after looking up my current fishfinders and their draw, about 2 amps and 1.7 amp for the Humminbirds, so switching to the Garmins at about 3 amps each, I definitely will be loading it down.
So I have been trying to find the best economical solution that gives me some flexibility.

I honestly do not have room for another full size battery, and even so switching to a dedicated electronics lithium will be expensive for the size I would need for a full day fishing. So here is what I am thinking

I have a 36V Terrova Trolling Motor that is 10 years old as well, I run it off 3 Interstate Group 31 Deep Cycle batteries (Which are all new this summer) They rate at about 100 Amp Hours. If I was to bite the bullet and upgrade to a Garmin Force Trolling Motor and run it at 24V, which they say is as powerful as my current 36V setup...that would free up a Group 31 Deep Cycle. I could then run all 3 fishfinders and possible LS later off this single battery as a stand alone electronics battery.

👍

[JohnnyO]

This is what I use. Have no issues, My set up is similar to yours
https://shop.advanceautoparts.com/p/...ial+battery+31