Multiple Fishfinders on One Battery, Recommendation?

[Bucks Bass and Bourbon]

Hey guys,

Thinking about switching from one dedicated lithium battery for each unit to one larger capacity battery to power all three units. I run two Garmin 126 Ultras and one 106 Ultra and my normal day on the water is usually 8 hours at the most. I do like the ability to go two full days in a row without having to charge but that isn’t a deal breaker. Livescope will remain on a separate dedicated battery so that isn’t a factor. I’m sure some of you guys are running a single battery like that so if you have experience with what works or what you tried and didn’t work please share. Thanks!

[MN Fisher]

Let's look at the stats

The 126's nominal draw is 3amps

The 106's nominal draw is 2.8amps

So total draw is 8.8amps

Time 8 hours is 70.4amps

Times 2 days is 140.8amps

 

If you're running Lithium - you'd need a 150ah battery for two days, or a 75ah battery for one day.

[Jig Man]

I am running 3 Humminbird Solix units on one 100 ah lithium with no issues.

[Tennessee Boy]

You just need to do the math that @MN Fisher has already done for you.  I run 3 Humminbird Solix, MEGA Live,  MEGA 360,  Target Lock on a 75 ah lithium.  I’ve never run out of juice but I’m rarely out more than 6 hours.  If I know it’s gonna be a long day I’ll put the units in sleep mode when I’m not using them.  I also have a switch to move stuff to the cranking battery if necessary but that has never happened.

[TnRiver46]

I ran two graphs off a lawn mower battery back

in the day. Forgot to turn one off once, stayed on in my carport for 6 days before I noticed 😂 

[Functional]

1 hour ago, TnRiver46 said:

I ran two graphs off a lawn mower battery back

in the day. Forgot to turn one off once, stayed on in my carport for 6 days before I noticed 😂 

you sure it wasnt just screen burn in? 🤣

[Bucks Bass and Bourbon]

I guess the draw from graphs is more consistent than what you figure from a trolling motor since they’re generally always on unless you put them in sleep mode whereas a trolling motor the draw can vary minute to minute based on the weather and current. 

[Tennessee Boy]

32 minutes ago, Bucks Bass and Bourbon said:

I guess the draw from graphs is more consistent than what you figure from a trolling motor since they’re generally always on

Absolutely.   Depending on how you use your trolling motor.  If you're like me and move around pretty slow they don't use much power at all.  I measured the current pulled by my 24V 80lbs Ultrex.  Here's what I found.  The first number is the trolling motor speed setting.  The second number is the amps pulled.  When I'm fishing the trolling motor is on 3 or less 80% of the time.

 

10 -  41

9 - 31

8.5- 27

8- 23

7.5–20

7-17

6.5-14.5

6-12

5.5-10

5-8

4.5-6

4-5

3.5-3.5

3-2.5

2.5-1.5

2-1

1.5-0.7

1-0.5

0.5-0.5

 

[Bucks Bass and Bourbon]

18 hours ago, Tennessee Boy said:

Absolutely.   Depending on how you use your trolling motor.  If you're like me and move around pretty slow they don't use much power at all.  I measured the current pulled by my 24V 80lbs Ultrex.  Here's what I found.  The first number is the trolling motor speed setting.  The second number is the amps pulled.  When I'm fishing the trolling motor is on 3 or less 80% of the time.

 

10 -  41

9 - 31

8.5- 27

8- 23

7.5–20

7-17

6.5-14.5

6-12

5.5-10

5-8

4.5-6

4-5

3.5-3.5

3-2.5

2.5-1.5

2-1

1.5-0.7

1-0.5

0.5-0.5

 

Very helpful,  thank you. What boat is your battery powering? My previous boat is a much lighter aluminum so the only times I went above 10 or 15% on the trolling motor was either moving quickly to a nearby spot and didn’t want to use the outboard or when I was moving against strong wind or current. Even at that I almost never went to much less above 50%. Except the time I forgot to raise my raptors and couldn’t figure out why my motor was having such a hard time getting anywhere 🙄

[Tennessee Boy]

22 hours ago, Bucks Bass and Bourbon said:

Very helpful,  thank you. What boat is your battery powering?

It an 18 foot aluminum Ranger RT188.