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 Battery | 56min | 1h 52min | 4h |
| 50Ah Battery | 1h 20min | 2h 40min | 5h 42min |
| 100Ah Battery | 2h 40min | 5h 20min | 11h 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 Battery | 42min | 1h 45min | 3h 30min |
| 50Ah Battery | 1h | 2h 30min | 5h |
| 100Ah Battery | 2h | 5h | 10h |
| 200Ah Battery | 4h | 10h | 20h |
LiFePO4 Batteries Compared
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 Battery | 48min | 1h 52min | 5h 36 mins |
| 2 x 50Ah Battery | 1h 8min | 2h 40min | 8h |
| 2 x 100Ah Battery | 2h 16min | 5h 20 min | 16h |
| 2 x 200Ah Battery | 4h 32min | 10h 40 min | 32h |
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 Battery | 42min | 1h 52min | 5h 36 mins |
| 3 x 50Ah Battery | 1h | 2h 40min | 8h |
| 3 x 100Ah Battery | 2h | 5h 20 min | 16h |
| 3 x 200Ah Battery | 4h | 10h 40 min | 32h |
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.
