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The short answer. An Ulterra stows and deploys itself, so a weak bank doesn’t just slow you down, it can leave the motor hanging. Both versions take a 60 A breaker. The QUEST runs 24 V or 36 V (60 A max draw, lithium “optimized”). The older Ulterra is 24 V at 80 lb (56 A) or 36 V at 112 lb (52 A); Minn Kota says it can run on lithium but is “specifically designed” for lead-acid, and prolonged speeds over 85% on lithium “could cause permanent damage” to the motor.
Which Ulterra do you have?
| Ulterra QUEST | Ulterra | |
|---|---|---|
| Thrust / volts | 90 lb at 24 V, 115 lb at 36 V (auto-detects) | 80 lb = 24 V, 112 lb = 36 V (fixed) |
| Max amp draw | 60 A either voltage | 56 A (80), 52 A (112) |
| Breaker | 60 A, MKR-27 | 60 A, MKR-19 |
| Factory leads | 8 AWG | 10 AWG |
| Lithium per manual | “optimized for use with LiFePO4” | “can run on Lithium-Ion” but “specifically designed” for lead-acid; prolonged speeds over 85% “could cause permanent damage” |
| Lead-acid size | Group 24/27/31, 70-125 Ah | 105 Ah or more |
Extension wire, batteries to leads: – QUEST 24 V: 6, 6, 4, 4, 2 AWG at 5, 10, 15, 20, 25 ft. QUEST 36 V: 6, 6, 6, 6, 4. – Ulterra 80: 8, 6, 6, 4, 2. Ulterra 112: 8, 8, 8, 6, 4.
Neither manual goes past 25 ft; both hand that to a marine technician.
Why voltage matters more on this motor
The Ulterra manual says the green System Ready light has to stay on after power-up. If it goes out, that’s “insufficient voltage/power”. Its troubleshooting steps are a good routine for any owner: check each battery on its own, check the series total, then check the voltage right at the motor’s B+ and B- wires. A big gap between the battery and the motor means the wire or a connection is eating volts. An error tone on deploy and a flashing battery icon on the remote point the same way.
The QUEST has a plan for a bank too flat to stow: power back on, deploy, trim the lower unit all the way up, then power off until you can charge. It also shuts itself down after 90 minutes stowed, which is the one time an auto motor saves a battery instead of draining one.
Lithium packs that fit
Neither manual gives a lithium amp-hour figure. Our fit rule: the pack’s voltage matches the motor, and its continuous discharge rating covers the max draw.
24 V (QUEST at 24 V, Ulterra 80): – Pro-Guide 24VM90 24V 90Ah lithium, 90 A continuous – Pro-Guide 24VM115 24V 115Ah lithium, 100 A continuous
36 V (QUEST at 36 V, Ulterra 112): – Pro-Guide 36VM60 36V 60Ah lithium, 60 A continuous, which is exactly the QUEST peak – Pro-Guide 36VM75 36V 75Ah lithium, 75 A continuous
On the QUEST, Minn Kota’s US rule is a battery that meets Coast Guard regulations and ABYC standards (E-13). That’s between you and the battery maker.
Example run times
Math from the Run time calculator, trolling mode: 80% of the amp hours divided by the amps, warm day. Halving the draw doubles the time.
| Pack | QUEST at 60 A | Ulterra at 56 or 52 A |
|---|---|---|
| 24VM90 | 1 h 12 min | 1 h 17 min (56 A) |
| 24VM115 | 1 h 32 min | 1 h 39 min (56 A) |
| 36VM60 | 48 min | 55 min (52 A) |
| 36VM75 | 1 h 00 min | 1 h 09 min (52 A) |
Peak draw is intermittent, per Minn Kota, so a fishing day runs longer than these.
Wiring and charging
Series wiring for 12 V batteries, two for 24 V and three for 36 V, is in Trolling motor battery: 12V, 24V or 36V, wired right. A single 24 V or 36 V pack needs only the breaker on the positive.
Both manuals put the same wall around the warranty: no charger or alternator that joins the trolling bank’s negative to the crank battery’s negative (the Ulterra’s bonding wire runs through a 3 A fuse), no accessories on the trolling bank, motor unplugged while charging.
Charge Pro-Guide packs to their own numbers, 28.8 V (24 V) or 43.2 V (36 V), with a multi-stage lithium charger. We don’t stock one at those voltages yet, and we don’t stock a 60 A breaker yet either. Minn Kota’s MKR-27 and MKR-19 are the parts it names.
Quick answers
Will low battery stop my Ulterra from stowing? It can. The QUEST manual gives a workaround: deploy, trim the lower unit fully up, power off, recharge.
Is the Ulterra lithium compatible? The older Ulterra can run lithium but is “specifically designed” for lead-acid; Minn Kota says prolonged speeds over 85% “could cause permanent damage to the motor.” The QUEST is optimized for LiFePO4.
What breaker for an Ulterra 112? 60 A manual reset. Minn Kota recommends the MKR-19 (MKR-27 for the QUEST).
Can I watch the battery on my Humminbird? With the QUEST, yes: HELIX G3N and newer, SOLIX and APEX, in 1% steps after you set the chemistry.
Sources
- Minn Kota Ulterra QUEST owner’s manual 2207124 (Rev F, 08/25), pages 5, 15-20, 59-60, 96, 101
- Minn Kota Ulterra owner’s manual 2207121 (Rev C, 09/24), pages 5, 15-18, 43-45, 76-80, 87, 91, 94
- Minn Kota Ulterra product page: https://minnkota.johnsonoutdoors.com/us/shop/freshwater-trolling-motors/ulterra
- Pro-Guide brochures and product pages
- Trolling motor battery: 12V, 24V or 36V, wired right, Run time calculator, Wire gauge calculator
