Trolling Motor Batteries: A Practical Guide

Trolling motor batteries have gotten complicated with all the options and marketing claims flying around. As someone who’s been through five different battery setups on various boats over twelve years, I learned everything there is to know about what actually matters versus what’s just hype. Today, I will share it all with you.

That’s what makes battery selection endearing to us anglers—there’s no single right answer, and what works brilliantly for one person is completely wrong for another. My buddy swears by his lithium setup that cost more than my first car. I’ve caught just as many fish running budget AGM batteries that cost a quarter of the price.

Types of Trolling Motor Batteries

Probably should have led with this section, honestly: three main types exist, and understanding the differences saves both money and headaches.

Lead-acid Wet Cell Batteries

The traditional flooded lead-acid battery your grandfather probably used. Cheap to buy, available everywhere, and they work. Maintenance means checking water levels occasionally and keeping terminals clean—maybe twenty minutes a season total if you stay on top of it.

The downsides are real though. Heavy. Less efficient. Shorter lifespan than newer technologies. Can leak acid if tipped. I ran wet cells for years because the price was right, but I’ve since moved on.

Absorbed Glass Mat (AGM) Batteries

AGM batteries sealed the deal for me—literally. No liquid to spill, no maintenance beyond keeping terminals clean, and they handle vibration and deep discharges better than flooded cells. Cost more upfront, but mine have lasted twice as long as the wet cells they replaced.

I’m apparently one of those people who forgets maintenance, and AGM batteries work for me while flooded cells never really did. The sealed design means I can install them in any orientation without worrying about leaks.

Lithium-Ion Batteries

Lithium is the new hotness, and the benefits are legitimate. Weighs roughly half what lead-acid does—noticeable when you’re carrying batteries to and from the boat. Charges in a fraction of the time. Lasts for thousands of cycles instead of hundreds.

The catch is price. A quality lithium trolling battery runs $800-1200 or more. Makes sense for serious tournament anglers who fish constantly. Harder to justify for weekend warriors like me, though I’m slowly coming around as prices drop.

Key Features to Consider

Battery Capacity

Capacity measured in amp-hours tells you how long the battery runs. My 100Ah AGM batteries get me through a full day of fishing with trolling motor use. Your mileage varies based on motor size, speed settings, and how much time you spend running versus drifting.

More capacity means more weight and more money. Figure out your actual usage before buying the biggest battery you can find—overkill just adds weight to the boat.

Voltage

Match the battery voltage to your motor requirements. 12V motors use one battery. 24V motors need two 12V batteries wired in series. 36V systems take three. Using wrong voltage damages the motor or leaves you underpowered. This isn’t the place to improvise.

Charging Time

Lithium batteries charge fast—often 2-4 hours from dead. AGM batteries take longer, typically 8-12 hours for a full charge. Flooded cells are similar to AGM. For me, overnight charging works fine since I fish weekends. Tournament anglers who need quick turnaround appreciate lithium’s speed.

Durability and Maintenance

Consider your realistic maintenance habits, not your aspirational ones. I thought I’d check water levels religiously; I didn’t. AGM’s sealed design matched my actual behavior better than what I promised myself I’d do.

Weight

A typical deep-cycle lead-acid battery weighs 60-70 pounds. AGM batteries run slightly lighter. Lithium equivalents weigh 25-30 pounds. Doesn’t sound like much until you’re hefting batteries up a boat ramp or trying to balance a small fishing boat. The weight difference matters more than I expected.

How to Maintain Your Trolling Motor Battery

Regular Inspection

Look at your batteries before each season at minimum. Corrosion on terminals reduces power. Cracks in the case mean replacement time. Bulging indicates internal damage. Catching problems early prevents being stranded.

Proper Charging

Get a charger matched to your battery type. Smart chargers with AGM settings prevent overcharging. Lithium batteries need lithium-specific chargers—using the wrong one can damage or destroy them. I label my chargers and batteries to avoid mix-ups.

Charge after every use, even if you didn’t run the battery down. Letting batteries sit discharged shortens their life significantly.

Storage

Cool and dry wins for battery storage. My garage works except during deep winter—I bring batteries inside when temperatures drop below freezing. Heat accelerates degradation; cold can cause freezing in discharged lead-acid batteries.

Depth of Discharge

Lead-acid and AGM batteries prefer staying above 50% charge. Running them dead repeatedly kills them faster. Lithium batteries tolerate deeper discharge but still last longer with shallower cycles. I installed a battery monitor that shows percentage—helpful for knowing when to head back to the ramp.

Top Recommended Trolling Motor Batteries

Based on personal experience and feedback from fellow anglers:

• Optima BlueTop AGM Battery — My current choice. The spiral cell design handles vibration well, and they’ve proven reliable over multiple seasons. Not the cheapest AGM option but worth the premium in my experience.
• Interstate Deep Cycle — Solid budget-friendly AGM batteries available almost everywhere. A friend runs them on his pontoon and gets good life out of them.
• Battle Born Lithium-Ion Battery — The gold standard for lithium trolling batteries. Expensive, but the weight savings and lifespan make the math work for heavy users. Built in the USA with a solid warranty.

Conclusion

The right battery depends on how you fish, how often you fish, and honestly how much you want to spend. AGM hits the sweet spot for most recreational anglers—better than flooded cells without lithium prices. Lithium makes sense if you’re on the water constantly or weight matters for your specific boat.

Whatever you choose, treat batteries well and they’ll take care of you. Neglect them and you’ll be paddling home eventually. Been there once; don’t recommend it.