Free tool
Trolling motor runtime calculator
Pick your motor, how hard you run it and how long you fish. See the battery size you need, how long a given battery will last, and what lithium saves you in weight.
Estimated runtime
–hours
Capacity you need
–Ah
0 h
Runtime by speed setting
Lithium vs. AGM for your trip
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How this is calculated
- Draw at partial speed is estimated as max draw × (speed %)1.5. Variable-speed motors follow this closely; older 5-speed motors waste more at low speeds.
- Usable capacity is 90% for lithium and 50% for AGM, the common limit to keep lead-acid batteries healthy.
- High-draw losses use Peukert's law with exponents of 1.05 for lithium and 1.20 for AGM, against a 20-hour rating.
- Weights are typical: about 0.26 lb per Ah for 12V lithium and 0.65 lb per Ah for 12V AGM.
- Minn Kota max draw figures come from Minn Kota's published specs: 60 A for QUEST models at 24V or 36V, 56 A for the Terrova 80, 52 A for the Terrova 112, 42 A for the PowerDrive 70 and 50 A for the Endura Max 55. Brushless QUEST motors are more efficient at partial speed, so real runtime may beat this estimate.
- Wind, current, weeds and spot-lock can add 10–30% to draw, so leave some margin.
Ready to pick one? See the best 12V, 24V or 36V batteries, or what battery your Minn Kota needs.