What Size Lithium Battery For 36V Trolling Motor?

Choosing the right power source is one of the smartest investments you can make for your boat. For 36V system boats, a 36V lithium battery keeps you fishing longer, reduces overall weight, and saves you from the hassle of frequent replacements. But if you’re wondering what size lithium battery for 36V trolling motor, you’re not alone.

This guide explains how to size a lithium battery for your 36V trolling motor, compares popular configurations, and shares practical tips so you can spend more time fishing and less time worrying about power.

Why Choose Lithium Battery for Trolling Motor?

When it comes to powering your trolling motor, you have a choice between traditional lead-acid (AGM) batteries and modern lithium (LiFePO4) batteries. Both can get the job done, but lithium trolling motor batteries offer several advantages that can make a big difference on the water.

1. Weight and Portability

• Lead-Acid (AGM): These batteries are heavy. A typical 12V 100Ah AGM battery can weigh 60–70 lbs, and if you need three for a 36V setup, that’s over 180 lbs.
• Lithium (LiFePO4): LiFePO4 batteries are much lighter, which often 50–70% less weight. A 12V 100Ah lithium battery may weigh only 20–25 lbs. A 36V lithium battery weighs only 30-60 lbs. Lighter batteries make your boat easier to handle and improve speed and fuel efficiency.

2. Run Time and Voltage Consistency

• Lead-Acid (AGM): Voltage drops gradually as the battery discharges, so your motor may lose thrust before the battery is empty.
• Lithium (LiFePO4): Lithium batteries maintain a steady voltage until nearly fully discharged. That means your trolling motor runs at consistent speed longer, giving you more reliable performance.

3. Charging Speed

• Lead-Acid (AGM): Slow to recharge. A full charge can take 8–12 hours, and overcharging can damage the battery.
• Lithium (LiFePO4): Recharge quickly in 2–4 hours with the proper charger, and they handle higher charge currents safely thanks to built-in BMS protection.

4. Cycle Life

• Lead-Acid (AGM): Typically 300–500 cycles before capacity noticeably drops. They can only last about 2-5 years.
• Lithium (LiFePO4): High-quality LiFePO4 batteries can deliver 4,000+ cycles, even with regular deep discharge, making them much more cost-effective over time.

5. Maintenance and Safety

• Lead-Acid (AGM): Generally low-maintenance but can develop corrosion, need cleaning, and are sensitive to overcharging.
• Lithium (LiFePO4): Virtually maintenance-free with integrated BMS protecting against overcharge, over-discharge, short circuit, and temperature extremes.

How to Choose the Right Size Lithium Battery?

To know what size of lithium battery for 36V trolling motor, follow the simple two steps:

1. Check Your Motor’s Amp Draw

Look in your trolling motor’s manual for its maximum amp draw. Many 36V motors with 112 lbs of thrust draw about 52–56 amps at top speed.

2. Estimate Your Time on the Water

Think about how long you fish between charges. Multiply the motor’s amp draw by the number of hours you want to run.

For example, if your trolling motor draw 52 amps at full speed, and you run it at a 25% speed in a 5-hour fishing trip:

52 amps × 25% speed × 5 hours = 65Ah (amp-hours of energy)

However, in reality, many anglers find that 50Ah to 100Ah covers most needs of 36V boats, depending on how hard and how long they run the motor.

A 50Ah lithium battery is sufficient for occasional fishing trips. If you want longer fishing times or plan to power other marine electronics, a 100Ah lithium battery may be a better choice.

3 12V 50Ah Batteries vs. 1 36V 50Ah Battery: Which is Better?

You may have heard that some anglers connect three 12V 50Ah batteries in series to create a 36V setup, while others go for a single 36V lithium battery instead. Which route makes the most sense for your fishing style and budget? Let’s explore the advantages and considerations of each setup.

Three 12V 50Ah Batteries for Trolling Motor

Advantages:

• Flexible: you can repurpose a single 12V lithium battery for lights or electronics.
• If one battery fails, you replace only that unit.
• Widely available, easier to find suitable charger and accessories

Considerations:

• Heavier and bulkier than one 36V pack.
• More wiring means more potential connection issues.
• Requires longer charging time for three packs.

One 36V 50Ah Lithium Battery for Trolling Motor

Advantages:

• Clean, simple installation with a single battery.
• No additional series or parallel configuration.
• Lighter and easier to fit in tight compartments.

Considerations:

• Requires a dedicated 36V lithium battery charger.
• If the pack fails, you replace the whole battery.
• Not as versatile for 12V applications.

Take an example as Redodo 12V 50Ah and 36V 50Ah LiFePO4 model:

Verdict:

If you prioritize neat wiring and space-saving, a single 36V 50Ah lithium battery is usually the winner. But if you already have 12V batteries or like modular setups, three 12V 50Ah batteries in series remain a solid choice.

Recommended Lithium Batteries for 36V Trolling Motor

Redodo 36V 50Ah Lithium Trolling Motor Battery

For those investing in a 36V trolling motor battery for the first time, this battery is a smart choice. It’s designed for 36V trolling motors up to 120 lbs of thrust. The single-battery setup costs less than using three 12V batteries in series. Plus, one pack makes charging and maintenance far simpler.

Key features:

• Weighs only 32.8 lbs
• Compact Group 31 battery size
• Low-temperature protection for cold weather
• Upgraded BMS for 20+ safety protections
• 60A continuous discharge in 30 mins for high thrust
• 250A peak surge for high-power demands

User review:

@Wilson:

I purchased the redodo 36v 50ah battery to power my 36v 112lb thrust Minn kota ultrex trolling motor. I can fish all day with plenty of power to spare. So far my redodo lithium battery has performed flawlessly and I would recommend redodo products to anyone who is looking to make the switch to Lithium batteries and be able to save some money.

Redodo 12V 50Ah Bluetooth Trolling Motor Battery

If you prefer a flexible 12V battery setup, consider three of the 12V 50Ah Lithium Trolling Motor Batteries wired in series create a dependable 36V system. It features low-temperature charging protection and added resistance to moisture and salt spray. Plus, it supports Bluetooth monitoring so you can check real-time status right from your phone.

Key features:

• Lightweight at 11.27 lbs
• Smart Bluetooth monitoring
• Low-temperature protection for cold weather
• Enhanced resistance to moisture, dust, and salt spray
• Support up to 4 batteries in series and parallel
• Versatile applications like RVs, fish finders, livescopes, and other marine electronics.

User review:

@John:

I’ve been using the Redodo 12V 50Ah trolling motor battery for a couple of months now, and I’m really impressed. I noticed was how light it is — at just over 11 lbs, it’s a breeze to carry compared to the heavy AGM batteries I used before. Installing it in my kayak was simple, and it instantly freed up space and weight.

On the water, my 55-lb thrust trolling motor runs smoothly, and the voltage stays steady right until the battery is nearly empty. I usually fish for 5–6 hours at a time, and this battery hasn’t let me down once.

Explore more high-performance trolling motor batteries at Redodo, and upgrade smart, long-lasting power!

Conclusion

Choosing the right lithium battery for your 36V trolling motor can make a big difference in performance, convenience, and peace of mind on the water. For amateur anglers, a 50Ah lithium battery is enough; while for passionate anglers, a 100Ah trolling motor battery provides uninterrupted power for all days.

For battery setup, a 36V trolling motor battery offers easier installation, and hassle-free maintenance compared to three 12V batteries in series. If you prefer flexibility setup, the 12V battery system is your ideal choice. With the right battery in place, you can spend more time fishing and less time worrying about power.

Read More:

[Full Guide] What Size Battery for Trolling Motor?

What Size Lithium Battery for 24V Trolling Motor?

How Long Does a Trolling Motor Battery Last?

Best Lithium Battery for Trolling Motor