How To Choose A Lithium Battery For Trolling Motors - Dakota Lithium Batteries

How To Choose A Lithium Battery For Trolling Motors

What type of battery do I need to run my trolling motor?

Most electric trolling motor will operate with any deep cycle 12-volt marine battery. But for the longest run time and lifespan we recommend lithium iron phosphate (LiFePO4) batteries. Here’s 5 reasons why:

  1. Dakota Lithium LiFePO4 batteries will provide double to triple the run time. More run time means more fishing time.
  2. Dakota Lithium batteries last longer and will need to be replaced less often. Providing piece of mind and greater lifetime value.
  3. Dakota Lithium weighs 60% less than deep cycle lead acid batteries. Less weight means more maneuverability and speed. And the batteries are easier to carry when you need to charge them.
  4. Dakota’s lithium iron phosphate works down to negative 20 degrees Fahrenheit (-29 Celsius) meaning you can power your boat in the summer and your ice fishing rig in the winter.
  5. You need less batteries when you use a Dakota Lithium. Lithium iron phosphate has a flat voltage curve. That means that the voltage does not drop as you use the battery. You get all the juice down to the last drop. Historically if you power a trolling motor with a deep cycle lead acid battery you would only be able to use half of the capacity of the battery before the voltage is too low to run the motor. With Dakota Lithium you can use all of the power of the battery, meaning that a 100 Ah battery from Dakota Lithium is equal to 200 Ah in lead acid batteries.


The Best Battery for Your Trolling Motor is Dakota Lithium

Motor Thrust / Max Amp Draw (A) @ Voltage (V) / Recommended Battery

How to calculate run time for a trolling motor battery

How long you can run your trolling motor depends on the max amp draw and if your battery is lead acid or Dakota lithium (see above). Also important is how often you run your trolling motor at the max power setting while on the water. Using a lower power setting = more fishing time!

Step 1: Determine the voltage of your motor. 12V motors are smaller, and more cost effective. They typically requires only one battery. 24V and 36V motors have more thrust and use more power, requiring multiple batteries (directions for how to link batteries in series to create a 24V or 36V battery are here). If cost is top of mind for you then a 12V motor may be a better choice. If power & performance is the most important then a 24V or 36V system may better meet your needs.

Step 2: Determine the amp draw of your motor. Max amp draw of your trolling motor should be less than < the max amp draw of your battery (also called continuous discharge rate). This means that your motor will never ask for more power than your battery is capable of giving at any one time. For many 12V motors the max amp draw is roughly equal to the lbs of thrust. So if you have a 30 lb motor the amp draw is most likely near 30 amps. 24v and 36v motors use less amps per pound of thrust. It is important to confirm the max amp draw with your motor manufacturer.

Step 3: Find a Dakota Lithium battery with a max continuous amp discharge that is greater than what your motor needs. Shop trolling motor batteries options here.

Here’s an example from Minnakota on how many amps their line of trolling motors draw. The larger the lbs of thrust the more power the trolling motor uses.

Please note: this chart is for educational purposes only and is not applicable to all trolling motors. Contact your trolling motor manufacturer for your model’s amp draw and instructions on rigging, including the use of fuses or circuit breakers.  

Motor Thrust / Max Amp Draw / Voltage

  • 30 lb / 30A @12V
  • 40 lb, 45 lb / 42A @12V
  • 50 lb, 55 lb / 50A @12V
  • 70 lb / 42A @ 24V
  • 80 lb / 56A @ 24V
  • 101 lb / 46A @ 36V
  • 112 lb / 52A @ 36V

For a all Dakota Lithium batteries the max continuous amp discharge for a 12 volt battery is roughly = to the total amp hours (Ah). For example a Dakota Lithium 23 Ah battery has a max continuous amp discharge of 24 amps. This is enough to power small 12v kayak fishing motors, but would not be enough for motors with more than 25lbs of thrust. For big motors you want a bigger battery. One way to create a larger continuous amp discharge is to wire two batteries in parallel. This will double the capacity (run time) and the max continuous amps. For example two Dakota Lithium 23Ah batteries wired in parallel would have the max continuous amps available to power a trolling motor with up to 45-50 lbs of thrust and a capacity of 46 amp hours (Ah). This is enough power for many kayak fishing and other small boats.

One important note, if you wire two batteries in series it will increase the voltage but not the max continuous amp discharge or the capacity (Ah). This is why most 24V or 36V trolling motors use 50 Ah batteries or larger. 24V and 36V motors have a high amp draw and needs multiple batteries in series to meet the power required. Wiring two smaller, 23Ah batteries in series may work, but you would only be able to use your motor for a short amount of time.

Step 4: Decide on how long you want to run your motor for each day. If you are a fish from dawn to dusk person (aka “full day”) you will want your battery to have double the capacity (Amp hours or Ah) of your motors max draw (for example, if your motor draws 25 amps you may want a 50 Ah battery). If you are a half day or run your trolling motor for just half the day you can use a battery where the capacity (Ah) is equal to your amp draw. For example, if you have a motor that uses 25Ah you might be fine with just one 23Ah battery.

Here’s the math to calculate run time: (Total capacity of the battery ÷ total max amp draw of your motor) × 60 minutes =  Run time for your trolling motor at maximum power setting*

* Using a lower power setting will significantly extend total run time. A deep dive on power settings and run time is available here.

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