Choosing Best Kayak Battery for Fish Finder and Trolling Motor

Kayak fishing is all about getting to those hard-to-reach spots and reeling in the big one, and a reliable battery for your fish finder and trolling motor is key to making that happen. Whether you’re scanning for fish or cruising across the water hands-free, the right battery can make or break your day on the water. This guide breaks down everything you need to know to choose the best kayak battery, with specific recommendations for different setups and tips to keep your gear running smoothly.

Why a Good Kayak Battery Is Important

Your fish finder helps you locate fish, underwater structures, and the best fishing spots, while a trolling motor lets you move efficiently without paddling, freeing up your hands to cast and reel. But kayaks have limited space and weight capacity, so your battery needs to be compact, lightweight, and powerful enough to last through your fishing trip. A poorly chosen battery can leave you stranded, add unnecessary weight, or fail in harsh marine conditions.

Key Factors to Consider

Here’s what to keep in mind when selecting a battery for your kayak’s fish finder and trolling motor:

1. Voltage
   • Most fish finders and small trolling motors (30-55 lb thrust) operate on 12V. Larger trolling motors or electric outboards may require 24V or 36V.
   • Always match the battery’s voltage to your equipment’s requirements to avoid damaging your electronics.
2. Amp Hours (Ah)
   • Amp hours measure how much energy a battery can store, directly affecting how long it can power your devices.
   • For fish finders, a 10Ah battery can last 10-16 hours, depending on the device’s power draw (0.1A for basic models, up to 1A for advanced ones with GPS and color displays).
   • For trolling motors, a 50Ah battery is the minimum for all-day use, while 100Ah is better if you’re also powering electronics.
3. Battery Type
   • Lithium-ion (LiFePO4): These are lightweight (often half the weight of lead-acid), long-lasting (up to 10 years), fast-charging (2 hours vs. 8+ for lead-acid), and corrosion-resistant, making them ideal for saltwater. They also have safety features like overcharge protection and can be discharged to 20% without damage.
   • Sealed Lead-Acid (SLA): Heavier, less efficient, and shorter-lived but more affordable. They’re better for cold environments but less practical for kayaks due to their weight and bulk.
4. Weight and Size
   • Kayaks have limited space and weight capacity, so lighter and more compact batteries are preferred. Lithium-ion batteries typically weigh 50% less than lead-acid equivalents.
5. Runtime
   • Calculate your fishing trip duration. A 10Ah battery might power a fish finder for a full day, but a trolling motor will drain it much faster. For combined use, opt for at least 50Ah.
6. Charging
   • Lithium batteries charge faster and can handle more charge cycles without degradation, making them more convenient for frequent use.
7. Safety
   • Look for batteries with waterproof ratings (e.g., IP65 or IP67) and safety features like protection against overcharging, undercharging, and short circuits.
   • Always store batteries in a waterproof box to prevent water damage, especially in saltwater environments.
8. Cost
   • Lithium batteries are more expensive upfront (often twice the cost of lead-acid) but offer better value over time due to their longevity and efficiency.
9. Compatibility
   • Ensure the battery’s voltage and capacity meet the requirements of your fish finder and trolling motor. Check the manufacturer’s specifications for guidance.
10. Additional Features
    • Some lithium batteries offer Bluetooth monitoring for real-time updates on charge, temperature, and battery life via a smartphone app.
    • Features like deep sleep modes can help conserve power when not in use.

Recommended Batteries for Different Use Cases

When choosing a best battery for your kayak, it’s important to consider what you’ll be powering. Here’s a breakdown of the battery requirements for different setups:

For Fish Finder Only

If you’re only using a fish finder, you don’t need a large battery. A smaller, lightweight battery with a capacity of around 10-20Ah is usually sufficient. Lithium-ion batteries are ideal because they are light, durable, and can handle the power needs of modern fish finders without adding unnecessary weight to your kayak.

For Trolling Motor Only

Trolling motors require more power, especially if you plan to use them for extended periods. A battery with a higher capacity, typically at least 50Ah, is recommended. Lithium-ion batteries are again the best choice due to their high energy density, which means you get more power in a lighter package. If budget is a concern, sealed lead-acid batteries can be used, but they are heavier and less efficient.

For Both Fish Finder and Trolling Motor

If you’re powering both a fish finder and a trolling motor, you’ll need a battery that can handle the combined load. This means opting for a higher capacity battery, similar to what’s needed for the trolling motor alone. Lithium-ion batteries are particularly advantageous here because they can provide the necessary power without the weight penalty of lead-acid batteries. Look for batteries with at least 50Ah to ensure you have enough power for a full day on the water.

Why Lithium Batteries Are the Best Choice

Lithium-ion (LiFePO4) batteries are the preferred choice for kayak fishing due to their numerous advantages:

• Lightweight: They weigh about 1/3 as much as lead-acid batteries, reducing strain and improving kayak balance.
• Long-Lasting: With a lifespan of up to 10 years and thousands of charge cycles, they outlast lead-acid batteries.
• Fast-Charging: Lithium batteries charge in about 2 hours, compared to 8+ hours for lead-acid.
• Corrosion-Resistant: Ideal for saltwater environments, reducing maintenance needs.
• Safe and Reliable: Many include built-in protections against overcharging, undercharging, and short circuits.
• Deep Discharge: Can be discharged to 20% without damage, unlike lead-acid batteries, which shouldn’t go below 50%.

While lithium batteries have a higher upfront cost, their durability and efficiency make them a better long-term investment. For most of the cases, the 12V lithium battery for kayak is the choice.

Battery Maintenance and Safety Tips

To get the most out of your kayak battery:

• Use a Waterproof Battery Box: Protect your battery from water damage, especially in saltwater. Look for boxes with secure seals and tie-downs.
• Secure the Battery: Place it near the seat for balance and use straps or tie-downs to keep it in place.
• Check Regularly: Inspect for signs of wear, corrosion, or damage before each trip.
• Follow Charging Guidelines: Use the manufacturer’s recommended charger and avoid overcharging.
• Consider Bluetooth Monitoring: Some lithium batteries offer smartphone apps to track charge levels, temperature, and battery health.
• Store Properly: Keep batteries in a cool, dry place when not in use to extend their lifespan.

Additional Considerations

• Separate Batteries for Fish Finder and Trolling Motor: Some anglers prefer using a smaller battery (e.g., 10Ah) for the fish finder and a larger one (e.g., 50Ah) for the trolling motor to avoid interference and optimize power usage. However, a single high-capacity battery can work for both if properly managed, though you may need a noise filter to prevent interference with the fish finder.
• Mounting: Small batteries for fish finders can be mounted inside the kayak’s hull with a foam holder. Larger batteries for trolling motors should be secured in a battery box near the seat.
• Environmental Factors: If you fish in extreme cold, lead-acid batteries may perform better, but lithium batteries with low-temperature protection are increasingly reliable.

Battery Requirements Summary

Conclusion

Choosing the best kayak battery for fish finder and trolling motor depends on your fishing style, budget, and equipment needs. For fish finders alone, a small 10-20Ah lithium-ion battery is ideal for its portability and efficiency. For trolling motors, a 50Ah or higher lithium-ion battery ensures all-day power without excessive weight. If you’re running both, a high-capacity lithium-ion battery (50Ah or more) is the best choice to handle the combined load. Investing in a lithium-ion battery is the smartest move for most kayak anglers due to its lightweight design, long lifespan, and fast charging. Whatever battery you choose, make sure it’s secure, waterproof, and compatible with your gear. With the right battery, you’ll spend less time worrying about power and more time reeling in those trophy fish!