Trolling Motor Batteries – Complete Guide | Deep Cycle & Marine Batteries

Trolling Motor Batteries

A trolling motor is only as good as the battery powering it. Choosing the right trolling motor battery ensures longer runtime, consistent performance, and reliable power while on the water. This guide will help you understand battery sizes, the difference between marine starting and deep cycle batteries, and how to maximize your trolling motor’s performance.

Looking for a replacement battery? Browse our Deep Cycle Marine Batteries or visit our Marine Batteries category.

Common Trolling Motor Battery Group Sizes & Capacities

Choosing the correct battery group size is important for trolling motor performance and runtime.

  • Group 24: 70–85 Ah — ideal for light-duty applications or small boats.
  • Group 27: 90–100 Ah — offers moderate runtime and power for most recreational boats.
  • Group 31: 100–125 Ah — heavy-duty option for anglers spending long hours trolling.

Pro Tip: A Group 31 deep cycle battery is recommended for extended trips and consistent performance.

What Size Battery Do You Need for Your Trolling Motor?

Battery size depends on your boat’s voltage system and motor thrust rating.

  • 12V System, up to 55 lbs thrust: Requires one 12V battery.
    • Good: 24DC with 70–85Ah
    • Better: 27DC with 90–100Ah
    • Best: 31DC with 100–125Ah
  • 24V System, up to 80 lbs thrust: Requires two 12V batteries in series.
    • Good: 27DC with 90–100Ah
    • Best: 31DC with 100–125Ah
  • 36V System, up to 120+ lbs thrust: Requires three 12V batteries in series.
    • Best: 31DC with 100–125Ah

Choosing the right capacity helps provide longer runtime, more consistent voltage, and reduced battery strain.

Why Battery Capacity Matters

Trolling motors draw steady power over long periods. Using a battery that is too small can:

  • Drain quickly and leave you stranded
  • Lose voltage under load
  • Shorten battery lifespan

Tip: More amp-hours (Ah) generally means longer runtime and more reliable performance on the water.

AGM vs Flooded Trolling Motor Batteries

AGM Batteries

  • Maintenance-free and spill-proof
  • Better vibration resistance
  • Longer cycle life in many applications
  • Convenient for boats where maintenance access is limited

Flooded Batteries

  • Lower upfront cost
  • Require regular maintenance
  • Must be installed upright
  • Best suited for users comfortable checking and maintaining water levels

For many anglers, AGM batteries offer a good balance of reliability, convenience, and performance.

How Long Will a Trolling Motor Battery Last?

Battery runtime depends on several factors:

  • Amp-hour (Ah) rating
  • Motor thrust and speed setting
  • Wind and water conditions
  • Weight of the boat and gear
  • Age and condition of the battery

Tip: For full-day trips, choose a higher-capacity deep cycle battery to help maintain consistent power.

Need Help Choosing the Right Trolling Motor Battery?

If you’re unsure which battery suits your boat, our team can help based on:

  • Motor thrust rating
  • Boat size
  • Typical usage
  • Available battery space
  • Charging setup

Contact Royal Battery Sales for help choosing the right trolling motor battery.

Frequently Asked Questions

Can I use a starting battery for a trolling motor?

No. Starting batteries are designed for short, high-current bursts to start engines. A deep cycle marine battery is the better choice for trolling motors because it is designed for steady power over a longer period of time.

How long will a 100Ah trolling motor battery last?

Runtime varies by motor thrust, speed, water conditions, and boat weight. In many cases, a 100Ah deep cycle battery can power a moderate trolling motor for several hours, but actual runtime will vary.

Should I choose AGM or flooded batteries for my trolling motor?

AGM batteries are maintenance-free, spill-proof, and vibration resistant. Flooded batteries usually cost less upfront but require regular maintenance and must remain upright.

What size battery is recommended for a full day of trolling?

For longer fishing trips, a Group 31 deep cycle marine battery with at least 100Ah capacity is usually recommended.

Browse our Deep Cycle Marine Batteries for trolling motors, fish finders, and other marine applications.