Equipping your trolling motor with the right lithium battery can make or break your fishing trip. Whether you're in a kayak, mid-sized bass boat, or large freshwater rig, getting the battery right means longer run times, lighter weight, and far less maintenance than traditional lead-acid setups.
In this guide, we’ll cover:
Why choose lithium (LiFePO₄) for trolling motors
Key battery specs to understand (voltage, amp-hours, discharge, etc.)
How to size your lithium battery based on motor thrust and runtime
Installation considerations, wiring, and BMS
Pros & cons, and real-world examples
Recommended models and comparisons
Lithium iron phosphate (LiFePO₄) is widely considered the top choice for marine and trolling motor use. Key advantages include:
Lightweight: Up to 60–70% lighter than comparable lead-acid batteries
High cycle life: Many LiFePO₄ packs last 2,000–5,000+ cycles
Stable voltage: Delivers near-constant voltage until nearly empty
Fast charging and high efficiency: Less energy lost during charge/discharge
Maintenance-free: No watering, no acid spills, sealed design
Better performance in cold conditions than lead-acid (though cold charging precautions apply)
Because of these benefits, many marine and fishing battery guides now rank lithium batteries as the best overall choice for trolling motor systems.
Before shopping, be sure you understand these critical specs:
| Spec | Meaning / Why It Matters |
|---|---|
| Voltage (V) | Must match your motor system—12V, 24V, 36V, etc. |
| Amp-Hours (Ah) | Capacity (how much energy) — higher Ah = longer runtime |
| Depth of Discharge (DoD) | How much of capacity is usable without harm; LiFePO₄ often allows 80–100% use |
| Continuous / Peak Current (A) | Battery must supply the amps your motor demands |
| Battery Management System (BMS) | Protects against overcharge, over-discharge, temperature, cell balancing |
| Cycle Life | Number of charge/discharge cycles before capacity degrades significantly |
| Weight & Size | Impacts boat balance, handling, space constraints |
These specs will help you compare different batteries and ensure you pick one that safely handles your motor's demands.
First, determine the power draw of your motor:
Motor is rated in voltage and wattage (or amps)
For example, a 12V 500W motor draws ~500W / 12V = ~41.7A
If unknown, you can measure using a DC amp meter while running the motor.
Decide how many hours or minutes you want the motor to run before recharging.
Example: You want your 12V motor to run for 4 hours at moderate load.
If your motor draws 41.7A and LiFePO₄ allows safe 90% discharge:
Required Ah=41.7×40.9≈186Ah ext{Required Ah} = rac{41.7 imes 4}{0.9} pprox 186 AhRequired Ah=0.941.7×4≈186AhSo you’d look for a lithium battery around 180–200Ah at 12V for that runtime.
If using 24V or 36V, similar logic applies—adjust the current draw accordingly.
Depending on motor and setup:
12V Systems: Use a single 12V lithium battery (~50–200Ah)
24V Systems: Use two 12V batteries in series, or a 24V lithium pack
36V Systems: Three 12V in series or a 36V lithium pack
Higher Volt Systems: Similar series wiring or purpose-built packs
Be sure all batteries used in series are identical type, capacity, and age to avoid imbalance.
Use heavy-gauge marine wiring, minimize voltage drop.
Keep leads short.
Use fused connections and proper terminal protection.
Make sure the BMS is accessible and ventilation is adequate (especially in enclosed compartments).
Ensure your charger is LiFePO₄ compatible—never use a standard lead-acid charger unless designed for lithium.
Also be wary of charging when very cold (<32°F / 0°C), as LiFePO₄ batteries may require a built-in temperature sensor or heating feature to protect them.
| Pros | Cons / Challenges |
|---|---|
| Light weight | Higher initial cost |
| Long cycle life | Requires proper BMS and charger |
| Stable voltage output | Charging in cold temps can be tricky |
| High efficiency, faster charging | Some models may be expensive or niche |
| Maintenance-free | Need to select correct size carefully |
For most serious anglers, the pros far outweigh the cons, especially when long-term reliability and performance are priorities.
For kayak anglers, a 12V 50Ah or 60Ah LiFePO₄ battery is popular because it offers good runtime at low weight.
For medium motorboats, the classic “sweet spot” is 12V 100Ah—enough power for full-day trolling under normal loads.
For high-thrust 36V motors, anglers now prefer 36V 50–100Ah lithium packs to replace multiple 12V batteries wired in series.
In forums, anglers report LiTime 100Ah performing well with 55 lb motors over several trips:
“The LiTime battery has worked for me. 100ah lasts a long time on a MotorGuide 55 pound.”
Here are some strong contenders:
| Model | Voltage / Capacity | Key Features |
|---|---|---|
| OKMO 12V 100Ah LiFePO₄ | 12V / 100Ah | Group size options, Bluetooth versions, high cycle ratings |
| MK Lithium / Dakota | 12V marine lithium lines | Strong reputation, durable build |
| LiTime 12V 100Ah | 12V / ~100Ah | Bluetooth monitoring, marine & trolling focus |
Each offers different trade-offs in price, features, size, and warranty.
Always charge after every use, even partial runs
Store battery at 50% charge if not using long-term
Clean terminals, check for corrosion
Monitor with Bluetooth or voltage gauge
Avoid deep discharge beyond recommended limits
Use the proper charger—never force a lead-acid charger on lithium
Choosing the best lithium battery for your trolling motor depends on matching the right voltage, amp-hour capacity, and system components. With lithium, you get major advantages—lighter weight, longer life, constant power output—that make your fishing trips more efficient, reliable, and less stressful.
If you're unsure, a safe bet for many setups is a 12V 100Ah LiFePO₄ battery for average trolling motors, and scale up (24V, 36V, or higher Ah) if your motor is large or you demand extended runtime.
