US Battery Supply Trolling Motor Size Guide

The US Battery Supply Trolling Motor Size Guide will help you decide, “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:

Dakota Lithium LiFePO4 batteries will provide double to triple the run time. More run time means more fishing time.

Dakota Lithium batteries last longer and will need to be replaced less often. Providing piece of mind and greater lifetime value.

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.

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.

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.

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The Best Battery for Your Trolling Motor is Dakota Lithium

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

20 lbs / 20A @ 12V /  DL+ 60 

25 lbs / 25A @ 12V /  DL+ 60

30 lb / 30A @ 12V / DL+ 60 or DL 100

45 lb / 42A @ 12V / DL+ 60 or DL 100

55 lb / 50A @ 12V /  DL+ 60 or DL 100 or DL+ 135

70 lb / 42A @ 24V / 24V Single or  DL+ 60 x 2 or  DL 100 x 2 or DL+ 135 x 2

80 lb / 56A @ 24V / DL+ 60 x 2 or DL 100 x 2 or DL 200 x 2 or DL+ 135 x 2

101 lb / 46A @ 36V / 36V Single or DL+ 60 x 3  DL 100 x 3 or DL+ 135 x 3 or DL 200 x 3

112 lb / 52A @ 36V / 36V Single or DL+ 60 x 3 or DL 100 x 3 or DL+ 135 x 3 DL 200 x 3

>112 lb / Up to 100A @ 36V / DL+ 60 x 3 or DL 100 x 3 or DL+ 135 x 3 or DL 200 x 3

How to calculate run time for a trolling motor battery

The total run time of your trolling motor will depend upon the power settings (max amp draw) that you are operating under and if your battery is lead acid or Dakota lithium (see above). It is key to understand how using your trolling motor for propulsion versus spotlock, will dramatically impact the overall runtime of your system. 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. See chart above for recommended battery size per max Amp draw. 

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 Minnkota 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 an 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 too small for most trolling motors. For most motors you want a bigger battery like the DL 60 or DL 100. 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 50 Amps the DL 60Ah battery may be more then enough run time for you.

Deciding which battery is right for you, factoring in the time that you plan to be on the water and the applications that you are using your motor for, will determine which Ah battery system is right for you. It is key to understand how using your trolling motor for propulsion versus spotlock, will dramatically impact the overall runtime of your system. You will use more power for extended periods of propulsion compared to spotlock. If your trolling motor is your primary means of propulsion, then we recommend opting for a higher Ah system that your budget will allow such as the 100Ah battery compared to the 60Ah 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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The Batteries Our Tournament Anglers Recommend:

The most common choices among #TeamDakotaLithium Fishing Pro Staff:

Motor Voltage & Pounds of Thrust / Recommended Battery / Performance

12v 30Lb Trolling motor / 12V 60Ah battery / Full day of runtime 

12v 55Lb Trolling motor / 12V 60Ah battery / Depending upon application, minimum half day of runtime. OR, 12V 100Ah Battery / Full day of runtime plus. This is the #1 choice for Kayak tournament fishing.

24v 80Lb Trolling motor / 24V 60Ah single pack or 2x 12V 60Ah batteries in series / Full day of runtime. OR, 2x 12v 100Ah batteries in series / Multiple days of runtime or tournament use.

36v 101 or 112Lb Trolling motor / 36v 60Ah LiFePO4 battery single pack / Full single day of runtime.  3x 12v 100Ah in series / Multiple days of runtime in heavy river current. #1 choice of our pro-bass fishing staff for tournament use.

36V Trolling Motors for off shore fishing and boats operating in remote locations. The Dakota Lithium Plus 36V 60Ah battery set allows you to jump start your boat engine off any single DL+ battery in the set (each DL+ battery has 1,000 CCA of engine starting power). #TeamDL Pro Staff, and off shore fishing guides, have found this provides added safety and redundancy when fishing in more remote locations, late at night, or anytime you are the only boat on the water.

Results may vary due to conditions, but this is a general consensus. Performance data based on 200+ pro-staff testing Dakota Lithium batteries in the most rugged of conditions.

Should I get a single 36V lithium battery OR Three 12V batteries in series?

Here at Dakota Lithium we build batteries to last a long, long time. Since 2008 Dakota Lithium staff have been testing our batteries in marine applications. Here’s what we have learned about single vs. multiple batteries wired in series. 

Advantages of a single 36V battery

Full single day of run time. A single Dakota Lithium 36V 60 Amp Hour (Ah) battery will power a trolling motor for a full day of runtime in river current. On a lake, or low power setting, some anglers report 2+ days of run time.

Simplicity. It is is easy to install. Easier to charge. Easier to use.

Ultra light weight. Upgrading from three 12V AGM or lead acid batteries in series to a single 36V battery will cut hundreds of pounds of weight from your boat.

Advantages of a three 12V batteries wired in series

Multiple days of run time on a single charge. The #1 choice of our pro-bass fishing staff for tournament use is 3x 12v 100Ah in series. Pro-staff have found they can fish for 2+ days on a single charge and can hold position in heavy current.

More versatile. You are not married to 36V forever. If you change your motor in the future you can still use the same battery bank. For example, one #TeamDakotaLithium Pro Bass angler transitioned trolling motors mid season from 36V to 24V and was able to use the same battery bank.

Can be repurposed for other uses. Lots of RVs and boats, and off-the-grid electrical systems run on 12V. If you decide you want a different trolling motor, or sell your boat then your batteries can be re-purposed for 12V uses.

Safety / Redundancy. The Dakota Lithium Plus 36V 60Ah battery set allows you to jump start your boat engine off any single DL+ battery in the set (each DL+ battery has 1,000 CCA of engine starting power). This provides redundancy when fishing in more remote locations, late at night, or anytime you are the only boat on the water.

We recommend connect ease trolling motor wiring kits when connecting multiple 12V batteries in series.

Charging your new Lithium battery:

All Dakota Lithium trolling motor batteries include a free lithium charger optimized for LiFePO4 battery chemistry. We recommend using the Dakota Lithium chargers with our batteries but other chargers may work. Most LiFePO4 or lithium specific chargers output 14.6- 14.8 V which does safely charge the batteries, but the DL chargers output 14.4V which help you get a slightly longer lifespan from your battery. AGM or lead acid chargers will charge the battery, but are optimized for the lower voltage of lead acid batteries, so they will read a lithium battery as full when it is only at 80% of full capacity.

Using your on-board charger: 

Most on-board chargers will work, but will only charge to 80% on the AGM setting. 

Can you use a DC-DC charger to charge while you are running your engine? 

Yes, this is a common practice to charge your batteries while your main engine is running. This will lead to extended battery life. 

How fast can I charge my batteries?

All Dakota Lithium batteries include a 10 Amp or 8 Amp charger, depending on model. Average charge time is 4 – 10 hours depending on how many Amp Hours (Ah) of battery capacity. For a faster charge time check out Dakota Lithium’s line of Ultra-Fast 20 Amp chargers. These larger, high output chargers will cut the charge time to 2-4 hours depending on battery size and are a good choice for tournament anglers, fishing guides leading multiple trips a day, and anyone who need a lot of power real fast.

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Source Dakotalithium.com Credit Dakota Lithium