Trolling Motor/Battery Question???

[barber4lyfe]

Just upgraded from a 12 volt, 46lb thrust motorguide tm to a 12 volt, 54lb on my tracker 175... it is currently running on 1 deep cycle battery, and was wondering if it would be more effective to parallel two batteries for longer use while out fishing. Any help and/or advice is greatly appreciated.. Thanks..

[Blueranger]

Are you having problems with your battery dying while you are fishing? Yes, you could parallel two batteries and it will extend your run time. What size battery are you currently running? You could also upgrade the size of your current battery for more amp hours.

[ff4145]

Kirk is right on, i would say the same

[Mdbasser]

If you need to run two batteries you should have gotten a 24 volt motor. You still will not have the power of a 24 but you will have the weight of two batteries.

[Squire]

I would do three things. One, get 2 31 (biggest) batteries, Optima Bluetop or your favorite AGM, free shipping from the Optima (I did this so you know it is fresh, not sitting on a shelf for 6 months, but J. Cash can get them cheaper apparently). I personally would not parallel them if you plan to leave them in the boat unless you also put a switch between them per what I have read on the web. Second, put a charger on your boat that switches the alternator from the cranking battery once it is recharged and uses the extra current to top up your TM battery. Lastly, due to issues I have had in the past, I now carry a portable charge that also has a tire inflator built in. Cast about 125 or so and if you have troubles on the road with tire inflation, you can fix it, or if you have trouble with the cranking battery because the electronics ran it down, you can jump quickly. I used to depend on the TM batterys for jumping, but if they are too depleted, you got troubles and you can lose a Tx you would have otherwise WON....Not a cheap solution I know, BUT, a ruined day on the water is a real waste....

[kickin bass]

We have a 55lb thrust minn kota saltwater trolling motor on our 18 ft G3 and the battery will last a solid 2 days of fishing without needing to be recharged. Even after an entire day fishing Briery or Sandy River or a whole day of windy Anna Sux, it shows no loss in power. We are running one Interstate deep cycle (not sure what size).

[Squire]

So, lets put the math to the discussion. 55lb thrust motors have an "amp draw" and here is the formulae to calculate how long your battery will last. NOTE, IMPORTANT to realize you have to cut in 1/2 the amp hours because you never want to take your battery down past 1/2 way, or you will have to replace it more quickly..

31 Series batteries can be up to 125 amp hours per some web searches I did. Thus the example below is excellent.
Per the Minnekota Motors website, the 55lb thrust trolling motors can consume at full power 50 Amp Hours per hour.


What is Amp Draw?

• Amp draw is the measurement of electrical current drawn from a storage battery (or battery), while the motor is being operated.
• Minn Kota’s published amp draw figures represent actual on-the-water conditions at full power (with all of the motor’s wiring, switches and circuitry in the electrical system as the test measurement is taken).
• Approximate length of running time when operating a motor at full power can be determined with a motor’s amp draw and the battery amp hour rating.
  
  • Example: A single 120 amp hour, 12-volt battery and a 12-volt trolling motor drawing 30 amps at the highest speed setting will run for about 3.4 hours.
• The formula for the calculation is as follows:
  
  • .85 A.H.R. = Hours of running time (A.H.R.= Battery Amp Hour Rating)
    M.A.D. (M.A.D. = Motor Amp Draw)
• As the speed setting is reduced the motor amp draw is also reduced.
• A motor drawing 30 amps at high speed may only draw 5 amps at the slowest speed. The same motor that will theoretically run about 3.4 hours at high speed will run for over 20 hours at the slowest speed

[skeet1]

Gotta like it when Steve brings in the math, it takes out the guess work

[31Airborne]

The 31-series battery was named after me. Just FYI.

Lol.

[barber4lyfe]

Thanks to all who gave advice/input... I will consider all suggestions and use the trial and error method until I find the best course of action that suits me... Thanks again...