what size battery for kayak trolling motor

2 min read 24-12-2024

what size battery for kayak trolling motor

Choosing the right battery for your kayak trolling motor is crucial for a successful fishing trip. Too small, and you'll be paddling home early. Too large, and you'll be lugging unnecessary weight. This guide helps you determine the ideal battery size for your needs.

Understanding Battery Capacity: Amp Hours (Ah)

The key spec to focus on is Amp Hours (Ah). This represents the battery's capacity – how much power it can deliver over time. A higher Ah rating means longer run time. Think of it like a fuel tank: a larger tank means you can travel further.

Small Kayak Motors (under 30lbs thrust): A 20Ah to 30Ah battery is often sufficient for shorter trips and calm waters.
Medium Kayak Motors (30-55lbs thrust): A 30Ah to 50Ah battery provides a good balance of power and portability. Expect 2-4 hours of runtime depending on usage.
Larger Kayak Motors (55lbs thrust and above): For longer trips or higher thrust motors, consider a 50Ah or even 100Ah battery. Expect longer runtime but increased weight.

Battery Types: Deep Cycle vs. Starting Batteries

Don't use a standard car battery! Kayak trolling motors require deep-cycle batteries. These are designed for slow, sustained discharge, unlike starting batteries which deliver a large burst of power for a short period.

Deep-cycle marine batteries: Specifically designed for marine applications, they're resistant to corrosion and vibration. They're also generally more expensive than other options.
Deep-cycle AGM (Absorbent Glass Mat) batteries: These are sealed and maintenance-free, making them convenient and spill-proof. They handle vibration well, suitable for kayaks.
Deep-cycle Lithium-ion batteries: These are lighter and more expensive than lead-acid alternatives, offering significantly longer runtimes and faster charging times. They're a premium choice.

Factors Affecting Battery Runtime

Several factors influence how long your battery lasts:

Motor Thrust: Higher thrust motors draw more power, reducing runtime.
Water Conditions: Currents and waves increase resistance, requiring more battery power.
Speed: Higher speeds consume more energy.
Motor Usage: Consistent use at full speed will drain the battery faster than intermittent use at lower speeds.

How to Calculate Battery Needs

There's no single formula, but consider these points:

Estimate your typical fishing trip length: How many hours do you usually spend on the water?
Consider your motor's Amp draw: Check your motor's specifications for the Amp draw at your typical speed.
Add a safety margin: It's wise to choose a battery with a slightly higher Ah rating than your calculated needs to account for unforeseen circumstances.

Frequently Asked Questions (FAQs)

Q: Can I use a car battery in my kayak trolling motor?

A: No. Car batteries are starting batteries, designed for short bursts of high power. They're not suitable for the sustained discharge needed by trolling motors. Use a deep-cycle battery.

Q: What's the best battery chemistry for a kayak trolling motor?

A: Lithium-ion batteries offer the best combination of weight, runtime, and lifespan, but they're more expensive. AGM batteries are a good balance of performance and cost.

Q: How do I charge my kayak trolling motor battery?

A: Use a compatible battery charger designed for the type of battery you're using (AGM, Lithium, etc.). Never overcharge the battery.

Conclusion: Choosing the Right Battery Size

Selecting the right battery for your kayak trolling motor depends on your individual needs and fishing style. Consider your motor's thrust, your typical trip length, water conditions, and budget when making your decision. Investing in a quality deep-cycle battery will ensure many enjoyable hours of fishing. Remember to always prioritize safety and use a properly sized battery for your setup.