Best Marine Batteries for 24V Trolling Motors: Series Wiring and Lithium Setup Breakdown

Run two 12V deep cycle batteries wired in series for your 24V trolling motor, or drop in a single 24V lithium unit if your budget allows it. I’ve tested both setups on Lake Ouachita for three seasons now, and the lithium option wins on every metric except upfront cost.

A 24V trolling motor needs 24 volts delivered consistently, not spikes and sags that kill your prop speed on the back nine holes of a tournament day. Get the wiring wrong and you’ll cook a battery or starve your motor of amps exactly when you need to hold position in current.

How 24V Series Wiring Actually Works

Series wiring connects two 12V batteries positive-to-negative, doubling voltage while keeping amp-hour capacity the same as a single battery. Two 100Ah 12V batteries in series gives you 24V at 100Ah, not 200Ah. That’s the number one mistake I see anglers make at the ramp.

The math matters because it determines your run time. A Minn Kota Terrova 24V pulling 30 amps at half throttle will drain a 100Ah series bank in roughly three hours of continuous use. Bump that to two banks in parallel-series (four batteries total) and you double your Ah capacity while keeping voltage at 24V.

I ran this exact configuration, four Group 27 batteries, on a river smallmouth trip last April. Full day on the water, motor running 60% of the time, and I still had 20% capacity left at the takeout.

Series vs. Parallel: Don’t Mix These Up

• Series wiring = increases voltage, keeps Ah the same (what you need for 24V systems)
• Parallel wiring = increases Ah, keeps voltage the same (used for 12V systems needing more capacity)
• Series-parallel = combines both, gives you 24V with doubled capacity (four batteries total)

Cross these wires wrong and you’ll either get 12V to your 24V motor or you’ll short the bank entirely. Check your polarity twice before you flip that battery switch.

Lead-Acid vs. AGM vs. Lithium for 24V Setups

Flooded lead-acid batteries are cheapest but they’re heavy, they off-gas hydrogen, and they hate deep discharges below 50%. I don’t recommend them for series 24V setups anymore. The weight penalty alone isn’t worth the savings.

AGM batteries are the middle ground I ran for six years before switching to lithium. Sealed, maintenance-free, and they handle deeper discharge cycles better than flooded lead-acid. The Renogy 100Ah AGM is a solid choice if you’re building a series bank on a budget. I’ve got two of these still running strong after 200+ charge cycles on my jon boat.

Lithium iron phosphate (LiFePO4) is where the technology has moved, full stop. Half the weight of AGM for the same capacity, 3,000+ charge cycles instead of 500, and you can discharge them to 20% capacity without shortening their lifespan. The premium is real. Expect to pay 3-4x what you’d spend on AGM. But the weight savings alone changes how your boat handles.

My Top Pick: Single 24V Lithium Units

If your budget stretches far enough, skip series wiring altogether and buy a purpose-built 24V lithium battery. One box, one BMS (battery management system), no series connection to fail at the worst possible moment.

The Battle Born 24V LiFePO4 is what I run now after switching off AGM two seasons ago. It weighs 55 pounds versus the 130+ pounds I was hauling with two Group 31 AGMs in series. That’s 75 pounds of dead weight gone from my bow, which matters when you’re running skinny water.

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If You’re Building a Series AGM Bank

For anglers not ready to drop lithium money, two matched AGM batteries in series is still a dependable setup. The key word is matched: same brand, same model, same age. Mixing batteries with different internal resistance in a series bank means one battery works harder and fails faster, taking the other one down with it.

I recommend the VMAX SLR125 for series builds. These are Group 31 batteries rated at 125Ah, and I’ve had good luck pairing two of them for a 24V/125Ah bank that powers a Minn Kota Riptide through a full day of saltwater flats fishing.

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Charging Your 24V Bank Correctly

This is where I see more failures than in the battery selection itself. You can’t charge a 24V series bank with a standard 12V charger connected to just one battery. You’ll overcharge one unit while leaving the other undercharged, and within a season you’ll have one dead battery and one that’s barely hanging on.

You need a multi-bank onboard charger designed to charge each battery independently even though they’re wired in series for the motor. The NOCO GEN2 handles this correctly. It charges each 12V battery in your series bank separately, which is exactly what you want.

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For lithium setups, you need a charger with a LiFePO4-specific profile. Lead-acid chargers will undercharge lithium batteries and never hit full capacity. Most lithium batteries, including the Battle Born unit I mentioned, ship with charging specs that require a dedicated lithium charger or a multi-chemistry unit set to the correct profile.

Charging Time Comparison

• AGM series bank (2x 100Ah): 8-10 hours on a 10-amp charger
• Lithium 24V (100Ah): 3-4 hours on a compatible lithium charger
• Fast-charge lithium options: under 2 hours with high-amp chargers

That charging speed difference matters if you’re running back-to-back tournament days and only have overnight to top off your bank.

What I’d Actually Buy

If money’s not the deciding factor, buy the single 24V lithium unit and skip series wiring complications entirely. Less weight, longer life, faster charging, and one less point of failure on the water.

If you’re working with a tighter budget, two matched AGM batteries in series still gets the job done reliably. Just buy them together, charge them with a proper multi-bank charger, and replace both at the same time when one starts showing weakness.

Don’t cheap out on the charger regardless of which battery type you choose. I’ve seen more battery banks killed by mismatched charging than by actual battery defects. Get the charging system right and your battery investment, lithium or AGM, will outlast your boat’s other electronics.

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