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  • Post last modified:April 24, 2025
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See charts to compare the run times of different battery sizes with 30, 55, 80 and 112 lb-thrust trolling motors.
Use the calculator to estimate run time based on your selected amp draw:

Methodology – How We Work Out Run-Time

We keep the math transparent:

Run-time (hours) = usable amp-hours ÷ average amp-draw

Usable amp-hours. We treat lithium (LiFePO₄) batteries as safely dischargeable to 80 % Depth of Discharge (DoD)—the sweet spot most lithium battery manufacturers quote for long cycle-life. A 100 Ah pack therefore delivers 80 Ah you can actually use on the water.

Average amp-draw. Check your trolling-motor manual or our Amp-Draw Chart for typical figures at low, medium and high speed. Remember to factor in any additional electrical equipment that may be using power from the battery while trolling.

Example: 80 Ah usable ÷ 20 A draw ≈ 4 hours of continuous run-time.

How to Use These Charts

1️⃣ Pick your motor thrust

2️⃣ Read across the column that matches your cruise speed

3️⃣ Choose the smallest battery size that still gives the run-time you need.

Remember: tables use average amp-draw figures; wind, current and frequent throttle changes can shorten real-world run-time.

30 lb Trolling Motor Battery Chart (12V)

A 30-pound-thrust motor is common on kayaks, canoes and jon boats. Because the amp-draw is modest, one 12 V battery does the job. Use the run-time table below to match your typical speed with the right
battery size.

Battery Bank
12V
Max Speed
30A
Med Speed
15A
Low Speed
7A
35Ah Battery56min1h 52min4h
50Ah Battery1h 20min2h 40min5h 42min
100Ah Battery2h 40min5h 20min11h 24min

55 lb Trolling Motor Battery Chart (12V)

Owners of inflatable dinghies and lightweight bass boats usually choose a transom-mount 55-lb motor. It still runs on a single 12-volt battery but draws almost twice the current of a 30-lb model, so capacity matters even more.

Battery Bank
12V
Max Speed
40A
Med Speed
16A
Low Speed
8A
35Ah Battery42min1h 45min3h 30min
50Ah Battery1h2h 30min5h
100Ah Battery2h5h10h
200Ah Battery4h10h20h

LiFePO4 Batteries Compared

Best Overall
Best Value
Lightweight
Best 24-Volt
100Ah 12V Lithium-Ion (LiFePO4) RV, Marine, Solar, & Off Grid Battery - Internal BMS, High & Low Temperature Protection - Battle Born Batteries
GrenerPower 12.8V 100Ah LiFePO4 Battery, Built-in 100A BMS, Max.1280Wh Lithium Iron Phosphate Battery with Up to 15000 Cycles & 10 Years Lifespan for RV, Camper, Solar Energy, Off Grid, Trolling Motor
ECO-WORTHY 12V 50Ah Trolling Motor LiFePO4 Lithium Battery with BMS, 3000~15000 Times in Deep Cycle, for 30~50lb Trolling Motor, Travel Trailer, RV, Marine, Solar, Power Wheel Chair
LiTime 24V 100Ah LiFePO4 Lithium Battery, Built-in 100A BMS, 4000+ Cycles Rechargeable Battery, Max. 2560W Load Power, Perfect for RV/Camper, Solar, Marine, Overland/Van, Off-Grid
Highlights
10-year warranty
Group 24 Size
Lightweight at 12.65 lb
No need to wire in series
Best Overall
100Ah 12V Lithium-Ion (LiFePO4) RV, Marine, Solar, & Off Grid Battery - Internal BMS, High & Low Temperature Protection - Battle Born Batteries
Highlights
10-year warranty
Best Value
GrenerPower 12.8V 100Ah LiFePO4 Battery, Built-in 100A BMS, Max.1280Wh Lithium Iron Phosphate Battery with Up to 15000 Cycles & 10 Years Lifespan for RV, Camper, Solar Energy, Off Grid, Trolling Motor
Highlights
Group 24 Size
Lightweight
ECO-WORTHY 12V 50Ah Trolling Motor LiFePO4 Lithium Battery with BMS, 3000~15000 Times in Deep Cycle, for 30~50lb Trolling Motor, Travel Trailer, RV, Marine, Solar, Power Wheel Chair
Highlights
Lightweight at 12.65 lb
Best 24-Volt
LiTime 24V 100Ah LiFePO4 Lithium Battery, Built-in 100A BMS, 4000+ Cycles Rechargeable Battery, Max. 2560W Load Power, Perfect for RV/Camper, Solar, Marine, Overland/Van, Off-Grid
Highlights
No need to wire in series

80 lb Trolling Motor Battery Chart (24V)

An 80-lb motor is the sweet-spot for midsize bass boats, pontoons and small center-consoles. It needs 24 V, which you get by wiring two 12-V batteries in series. Check the chart to see how run-time scales at low, medium and high speed.

Battery Bank
24V
Max Speed
35A
Med Speed
15A
Low Speed
5A
2 x 35Ah Battery48min1h 52min5h 36 mins
2 x 50Ah Battery1h 8min2h 40min8h
2 x 100Ah Battery2h 16min5h 20 min16h
2 x 200Ah Battery4h 32min10h 40 min32h

112 lb Trolling Motor Battery Chart (36V)

These powerful trolling motors live on heavy, high-freeboard boats and demand a 36V battery bank (3 × 12 V in series). If you fish rough water or run long distances on the trolling motor, start your planning with this chart.

Battery Bank
36V
Max Speed
40A
Med Speed
15A
Low Speed
5A
3 x 35Ah Battery42min1h 52min5h 36 mins
3 x 50Ah Battery1h2h 40min8h
3 x 100Ah Battery2h5h 20 min16h
3 x 200Ah Battery4h10h 40 min32h

Depth-of-Discharge (DoD) & Why It Matters

Lead-acid batteries lose both capacity and life when regularly drained below 50%, so budget for twice the amp-hours you expect to use.

Lithium (LiFePO4) packs, by contrast, are happy at 80 % DoD and still hold a healthy charge after 3000+ cycles.

Battery Type and Longevity

Lead-acid batteries will typically last around two or three years with regular use, as they are prone to sulfation (the buildup of sulfate crystals on the plates) when stored for long periods of time.

Lithium batteries don’t suffer from this problem.

  • Flooded / AGM lead-acid: 200–300 cycles, 2-3 yr typical life, prone to sulfation during storage.
  • LiFePO4 lithium: 3 000+ cycles, 5-10 yr life, no sulfation, weighs ~60 % less.

Warranty Cheat-Sheet

Expect 1-2 yr coverage on budget lead-acid, up to 5 yr on premium AGM, and 5-10 yr on reputable lithium brands.

Always read the fine print for cycle-life or temperature exclusions.

FAQ

Does depth-of-discharge matter for lithium batteries?

Yes—keeping at or above 20 % State-of-Charge dramatically extends cycle life.

Can I use the same run-time formula for lead-acid batteries?

You can, but plug in 50 % DoD for lead-acid; deeper discharges shorten their lifespan.

Why is my real-world run-time sometimes shorter?

Wind, current, extra gear weight and throttle changes all raise amp-draw, cutting run-time.

What amp-draw figure should I enter in the calculator?

Use the average draw you expect for the day; using peak draw will underestimate run-time.

Will temperature affect lithium battery run-time?

Yes—below 32 °F / 0 °C lithium batteries can lose about 10 % of effective capacity.