Marine Lithium Batteries
Power Your Adventure With Thor
Thirty Years of Battery Knowledge. Built Into Every Cell.
The marine environment doesn't forgive weak equipment. Salt air, heat, vibration, and the load demands of running a trolling motor, livewells, forward-facing sonar, and a full electronics setup simultaneously, your battery has to handle all of it without flinching. Thor Lithium marine batteries are built for exactly that, backed by a 10-year warranty and people who have put these batteries through nearly 300 days a year on the water themselves.
Built for the Long Days and the Early Mornings.
Every Thor Lithium Marine Battery is built with the features that matter most when you're on the water. No shortcuts, no compromises. Just reliable power backed by technology and people you can count on.
Questions About Marine Lithium Batteries?
The best marine lithium battery is the one properly sized for your specific boat, your electronics setup, and how you fish. For most bass boats and inshore fishing rigs, a 36V lithium battery for the trolling motor and one or two 12V batteries for electronics and accessories cover the majority of setups.
Larger boats with heavier power demand: livewells, multiple sonar units, Power-Poles, and lighting may need additional capacity in the electronics bank. Thor Lithium batteries are built on LiFePO4 chemistry, which delivers stable voltage, deep discharge capability, and a lifespan measured in thousands of cycles rather than hundreds. If you’re not sure where to start, call us. We’ll walk through your setup and make sure you’re not over- or under-buying.
Most fishing boats run at least two separate battery banks: one dedicated to the trolling motor and one for the outboard starting battery and onboard electronics. Many serious anglers run three or more. The right number depends on your trolling motor’s voltage requirements, how long your average day on the water lasts, and what electronics you’re running simultaneously.
A 36V trolling motor setup requires three 12V batteries wired in series, or a single dedicated 36V lithium battery. A 24V setup requires two 12V batteries in series or a single 24V battery. For your electronics bank, a single 12V 100Ah Thor Lithium battery handles most setups comfortably through a full day.
If you’re running multiple high-draw sonar units, livewells, and accessories, step up to a 150Ah or 175Ah. We’re happy to help you build the right system for your specific rig.
Most late-model outboards are compatible with lithium battery charging, but it is important to verify this for your specific engine. Older outboards may not regulate voltage properly for lithium chemistry, which can cause issues over time. If your outboard is compatible, it will charge your Thor Lithium batteries while underway, which is a significant advantage for anglers running long days or multi-day trips.
For boats where outboard compatibility is uncertain, a DC-to-DC charger between the outboard’s charging circuit and the lithium battery bank is the cleanest and safest solution. This is a relatively straightforward addition and ensures your batteries charge properly regardless of the outboard’s native output. When in doubt, check with your boat dealer or give us a call. We’ll help you figure out the right setup.
Yes, and it’s worth understanding why. Thor Lithium batteries use lithium iron phosphate (LiFePO4) chemistry, which is fundamentally different from the lithium cobalt oxide chemistry found in consumer electronics like phones and laptops. LiFePO4 is chemically stable, non-flammable under normal operating conditions, and purpose-built for deep-cycle marine applications. Every Thor Lithium battery includes a built-in Battery Management System that continuously monitors cell voltage, temperature, and current draw.
If any condition falls outside safe operating parameters, the BMS responds automatically before damage occurs. LiFePO4 batteries do not leak acid, do not vent explosive hydrogen gas, and do not carry the thermal runaway risk associated with other lithium chemistries. They are, by most measures, the safest deep-cycle battery chemistry currently available for marine use.
Significantly. A standard 12V 100Ah lead-acid battery weighs between 60 and 70 pounds. An equivalent Thor Lithium battery weighs roughly 25 to 30 pounds. On a bass boat running three trolling motor batteries and a dedicated electronics battery, switching to lithium can remove 100 to 150 pounds or more from the boat. That weight savings shows up immediately in top-end speed, fuel efficiency, hole shot, and how the boat handles in rough water.
For anglers fishing shallow water, the reduced draft from a lighter bow can be the difference between reaching a spot and running aground. The performance gains from weight reduction alone make the switch worth serious consideration, before you factor in the battery life, runtime, and maintenance advantages.
Yes, but you need the right model. Starting a large outboard requires high “Cranking Amps.” Ensure you select a model specifically rated for starting/cranking (like our 12V 100Ah Starting/Deep Cycle) to ensure the BMS can handle the high-amp surge of the starter motor.
