Batteries

[Mattfran]

Is it possible to run 2 trolling motors and a garmin graph on one battery in my John boat?

[slonezp]

Anything is possible. Might not be the best way to do things but, it will work depending on how you set it up.

[padlin]

One motor at a time?

[MN Fisher]

48 minutes ago, Mattfran said:

Is it possible to run 2 trolling motors and a garmin graph on one battery in my John boat?

 

5 minutes ago, slonezp said:

Anything is possible. Might not be the best way to do things but, it will work depending on how you set it up.

^ What Paul said - in my old canoe, I ran everything off of one 75ah gel-cell battery. 30# Endura TM, Garmin Striker 7cv, my tablet and a camera. I'd get 4-5 hours and still be above 50% charge.

 

So yes, it is possible - but not ideal.

[casts_by_fly]

Not much point really. I assume you mean one on the front and one on the back. You can’t run both at the same time as that’s too much draw on the battery. You also won’t gain speed as the hull design.  So you’re just as well to use the bow mount only and leave the other at home.

 

for the fish finder, you’re likely to have interference if you’re running the ff and the motor at the same time. 
 

best bet, get a small battery for the fish finder and focus on one trolling motor. If you really want to use two, pick up another group 27.

[Bird]

My graph experienced interference when I ran it with trolling motor battery.

 

[MN Fisher]

6 minutes ago, Bird said:

My graph experienced interference when I ran it with trolling motor battery.

 

I put a filter on the power line to the graph - didn't see any interference on mine.

[GaryH]

11 hours ago, Mattfran said:

Is it possible to run 2 trolling motors and a garmin graph on one battery in my John boat?

It would depend on what trolling motors are you using? What battery are you using? And how long and far from your ramp are you planning on fishing? All these variables play into whether or not it would be feasible. 

[Mattfran]

18 hours ago, padlin said:

One motor at a time?

Yes motor at a time 

[Mattfran]

Thank you for all of your answers. Was going to use one motor at a time. Use one motor and a graph with sidevu and mapping while traveling. And one on the front with clearvu while fishing was wondering if the 36v battery would work

[Mattfran]

18 hours ago, casts_by_fly said:

Not much point really. I assume you mean one on the front and one on the back. You can’t run both at the same time as that’s too much draw on the battery. You also won’t gain speed as the hull design.  So you’re just as well to use the bow mount only and leave the other at home.

 

for the fish finder, you’re likely to have interference if you’re running the ff and the motor at the same time. 
 

best bet, get a small battery for the fish finder and focus on one trolling motor. If you really want to use two, pick up another group 27.

Can u recommend a small battery for the fish finder

[padlin]

If it were me, I'd use an A/B switch, actually they are A/B/Both switches, just use the A and B for the motors and the battery as the common, or just use quick connects. Folks say you'll get interference on the fish finder so pick up a small 8 amp 12v battery for it. BPS or Cabela's sells them for $20+/-

[Way2slow]

It's possible it may work flawlessly.  It's also possible it may not work worth a darn.  There are several possible problem areas.  First one, running the graphs off the same battery as the TM.  Depending on the TM and the graph you are running, there's always the chance of getting interference on the display caused by the TM.  Second, there is the possibility the signals from two sonars on causing one or both sonars to receive both signals, causing a big mess on the display.  I think it will just depend on how the planets are aligned when you use it.  Like I said, may work picture book perfect, or may be totally useless.

Since I don't fish and cut grass at the same time, it don't take five minutes for me to take the battery out of my mower and put it in the jon boat to run the sonars on.

[casts_by_fly]

1 hour ago, Mattfran said:

Thank you for all of your answers. Was going to use one motor at a time. Use one motor and a graph with sidevu and mapping while traveling. And one on the front with clearvu while fishing was wondering if the 36v battery would work

no.  The voltage is the same regardless of how many things you have on it. If you hooked up two motors and two fish finders to a 36v battery you’d immediately have two blown fish finders and probably two blown motors. 

 

1 hour ago, Mattfran said:

Can u recommend a small battery for the fish finder

if you plan to run two fishfinders and two motors (still don’t know why two motors) then you’ll need three batteries. I don’t know your usage plan, but I’d be looking to a pair of group 27 (one for each trolling motor) and another smaller battery for the ff. If you can swing lithium then an 18 Ah lithium should hold you for the fishfinders.  If no lithium, then you’ll want a 30 Ah capacity lead acid.  

[Mattfran]

2 minutes ago, casts_by_fly said:

no.  The voltage is the same regardless of how many things you have on it. If you hooked up two motors and two fish finders to a 36v battery you’d immediately have two blown fish finders and probably two blown motors. 

 

if you plan to run two fishfinders and two motors (still don’t know why two motors) then you’ll need three batteries. I don’t know your usage plan, but I’d be looking to a pair of group 27 (one for each trolling motor) and another smaller battery for the ff. If you can swing lithium then an 18 Ah lithium should hold you for the fishfinders.  If no lithium, then you’ll want a 30 Ah capacity lead acid.  

Just one fish finder

[WRB]

Yes, expense however...$1,100

VMax Tank LFPG2-12175XTR LiFeP04 Li Iron is a 12V, 175 AH

Lithium Ion battery that weighs 38.5 lbs. you will need a lithium battery charger and 50 amp circuit breaker*, filter* the sonar power line.

You can also go with a 200 AH AGM marine battery, weight 125 lbs...not Jon boat friendly.

Tom

* need for any single 12V marine battery.

[Way2slow]

I just ran two graphs, two days on my mower battery and it was down very little.  You are probably looking at less than one amp each.  Even at 2 amps, one of those small 20 amp hour batteries should run you six to eight hours running both sonars at the same time.

Understand also, just because you are running a 36 volt system, each battery in the system is still just a 12V battery.  As long as you connect the sonar to the negative and positive of the same battery, it's still just being connected to 12 volts.  Just be sure it's the same battery.

Now, if you are talking about one 36 volt battery, then no, it will smoke everything.

 

[WRB]

3ea 12V deep cycle batteries in parallel = 12V and weighs over 100 lbs.

Running a  smaller “house” 12V battery for the electronic solves the problem.

Tom

[Tennessee Boy]

I recommend a simple approach.  Try it and if it doesn’t work fix it.  Trolling motor have been known to cause interference on electronics when connected to the same battery.  It’s not guaranteed.  On my first boat I always connected my electronics to my two trolling motor batteries connected in parallel.  During the time I owned the boat it had two different trolling motors and four different fish finders.  I never saw any interference.  It will take 30 seconds to determine if you have interference.  If you do get a second small battery.

[volzfan59]

On 3/7/2022 at 8:22 PM, MN Fisher said:

I put a filter on the power line to the graph - didn't see any interference on mine.

@MN Fisher, What filter did you use?

[MN Fisher]

5 minutes ago, volzfan59 said:

@MN Fisher, What filter did you use?

Just a clip-on ferrite noise filter..

https://www.amazon.com/VSKEY-Anti-Interference-Telephones-Equipment-Appliances/dp/B078XKHLKG/ref=sr_1_4?crid=RLDIRUFQZX8G&keywords=powerline%2Bfilters%2B12v&qid=1646834424&sprefix=powerline%2Bfilters%2B12v%2Caps%2C82&sr=8-4&th=1

[TnRiver46]

14 hours ago, Way2slow said:

I just ran two graphs, two days on my mower battery and it was down very little.  You are probably looking at less than one amp each.  Even at 2 amps, one of those small 20 amp hour batteries should run you six to eight hours running both sonars at the same time.

Understand also, just because you are running a 36 volt system, each battery in the system is still just a 12V battery.  As long as you connect the sonar to the negative and positive of the same battery, it's still just being connected to 12 volts.  Just be sure it's the same battery.

Now, if you are talking about one 36 volt battery, then no, it will smoke everything.

 

I also use lawn mower battery for electronics , they are $20! Haha

[GaryH]

5 hours ago, TnRiver46 said:

I also use lawn mower battery for electronics , they are $20! Haha

I’m gonna shoot you a pm in a minute.