What Size Battery Do I Need for a 112 lb Trolling Motor?
Above 80 lb the system is 36 V: three batteries in series. The amp draw is lower than the 80 lb motor because the voltage is higher.
Direct answer: Minn Kota lists a 112 lb motor at 52 A and 36 V, and thrust above 80 lb uses three 12 V batteries in series (Minn Kota battery chart; Minn Kota power article). Each battery should be at least 110 Ah. The series string is still 110 Ah, so 110 ÷ 52 is about 2.12 hours at the maximum draw, which the chart says is intermittent and is a worst case (Minn Kota battery chart).
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112 lb is a 36 V motor at 52 A on the chart (Minn Kota battery chart). The lower amp number versus an 80 lb motor (56 A at 24 V) is not a smaller battery bank. The volts went up.
Count is three batteries, the step for thrust above 80 lb, wired in series. Four batteries are the E-Drive 48 V case, which this motor is not (Minn Kota power article).
Do not multiply 110 Ah by three. Series wiring makes 36 V and the amp-hour rating stays that of one battery. 110 ÷ 52 = 2.12 hours at the maximum. Label that as a worst case: the chart says maximum amp draw occurs intermittently and is not a continuous rating (Minn Kota battery chart; Minn Kota power article).
The 6–8 hour recommendation is 110 Ah per battery, including each of these three (Minn Kota power article). If you need longer than the 2.12 hour floor, add a parallel string rather than a fourth battery in series (Minn Kota power article).
Group 31 at 95–125 Ah is the chart's Best tier and the one that extends above 110 Ah. Group 27 at 85–110 Ah only touches the recommendation at the top end. Group 24 at 70–85 Ah is below it. Buy that rating three times (Minn Kota battery chart).
Each battery in the string carries the full 52 A. Lithium has to supply that maximum continuously (Minn Kota power article). 52 A is under the 100 A continuous rating (Battle Born 100 Ah manual). Hold brushed motors to 85% or speed 8.5 or lower even though the pack is 36 V (Minn Kota power article). A 100 Ah lithium battery still sits under the 110 Ah per-battery guide.
Lead-acid at about 50% depth of discharge means each of the three batteries needs about a 220 Ah nameplate to yield 110 Ah usable. Usable amp-hours of the string are still 110 Ah, because series does not add them (Battle Born chemistry guide; Minn Kota power article). The manual's lithium cells are the 100% usable comparison, not a 36 V pack by themselves (Battle Born 100 Ah manual).
The breaker note remains 50 A or 60 A as listed per motor (Minn Kota battery chart). This page links a 60 amp breaker search and does not claim the excerpt assigns 60 A to the 112 lb row specifically.
What size battery do I need for a 112 lb trolling motor?
Three 12-volt batteries in series, each at least 110 Ah, for 36 volts. Minn Kota lists 112 lb at 52 amps and 36 volts, and thrust above 80 lb uses three batteries (Minn Kota battery chart; Minn Kota power article).
What is the worst-case runtime?
About 2.12 hours on a 110 Ah series string, because 110 ÷ 52 = 2.12. Maximum amp draw is intermittent, so this is the full-throttle floor (Minn Kota battery chart).
Why three batteries if the draw is 52 amps?
The count is about voltage. Series wiring makes 36 volts, and each battery still carries the 52 amp draw. 52 amps is under a 100 amp continuous lithium rating, and 110 Ah is the runtime guide per battery (Minn Kota power article; Battle Born 100 Ah manual).
Which group size should each battery be?
Group 31, listed as Best at 95–125 Ah, so the battery can reach 110 Ah. Group 24 at 70–85 Ah and group 27 at 85–110 Ah sit at or under that line (Minn Kota battery chart).