The Boss Hog is a 36V lithium trolling motor battery that lets you fish a full day on one battery instead of hauling three. It replaces the three 12V lead-acid or gel batteries a 36-volt trolling motor normally needs, cuts a large amount of weight off the bow, and frees up space in your battery compartment. You get much more consistent trolling-motor performance through the discharge cycle, plus a phone app that shows exactly how much charge you have left.
The Boss Hog (model MML-36100B) is a 36V 100Ah LiFePO4 deep cycle battery from Monster Marine Lithium, a battery company started by anglers, available from Lithium Battery Supply as an authorized Monster Marine Lithium dealer. It is built for one job: powering a 36-volt trolling motor through long days on the water without the dead-battery worries that come with lead-acid.
If you have been running three heavy batteries wired together, this is the simple upgrade: one battery, one positive and one negative connection. It is backed by Monster Marine Lithium's 15-year tiered warranty.
Quick Facts
- Replaces three 12V batteries with one 36V battery
- Weighs 59 lbs, up to about 150 lbs lighter than a three-battery lead-acid setup
- 100Ah of usable deep cycle power (3,840 watt-hours)
- Built-in Bluetooth, monitor charge and health from your phone (iPhone and Android)
- Fits Minn Kota, Garmin, Lowrance, Rhodan and other 36V trolling motors
- Delivers up to 100A continuous, enough for the full range of 36V trolling motors
- 15-year tiered warranty; requires a 36V lithium charger (available as an add-on)
Features and Benefits
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One battery instead of three. A single 36V case does the work of three 12V batteries: less wiring, fewer terminals to corrode, and one battery to monitor instead of three.
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Major weight savings. At 59 lbs, the Boss Hog can take up to roughly 150 lbs off the bow compared with three lead-acid batteries. Your boat sits better, gets on plane easier, and is simpler to load.
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Steadier power as it drains. Lead-acid gets weaker as it discharges, so your motor slows late in the day. LiFePO4 holds a much flatter voltage, giving you more consistent trolling-motor performance deep into the charge instead of a steady fade.
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See your charge on your phone. Built-in Bluetooth connects to the free MMLithium app (iPhone and Android) so you can check remaining charge, live power draw, and battery health anytime.
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Room to grow, with added redundancy. Add a second Boss Hog in parallel for 200Ah of total capacity. Running two also adds redundancy, since either battery may be able to power the motor on its own if it can be safely isolated with a switch or disconnect.
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Built to last for years. Rated for 4,000+ charge cycles, designed to outlast many sets of lead-acid batteries, which usually need replacing every few seasons.
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Made for the marine environment. A tough marine-grade housing and solid brass bolt terminals handle vibration, spray, and the pounding of a boat running across chop.
Boss Hog vs Three Lead-Acid
|
Boss Hog (one 36V) |
Three 12V lead-acid |
| Batteries needed |
1 |
3 |
| Approx. total weight |
59 lbs |
roughly 180 to 210 lbs |
| Usable capacity |
full 100Ah |
about 50% recommended |
| Wiring |
one positive, one negative |
series jumpers between three cases |
| Voltage under load |
stays flatter through the cycle |
fades as it drains |
| Monitoring |
Bluetooth app |
none built in |
| Rated cycle life |
4,000+ cycles |
typically a few seasons |
Fits Your Setup
The Boss Hog is a 36-volt battery made for 36-volt trolling motors. The rule is simple: match the battery to your motor's voltage. A 36V motor needs a 36V battery. It is not made for 12V or 24V trolling motors.
Works with these trolling motors
- Minn Kota 36V (Ultrex, Ulterra, Terrova, Fortrex, Riptide and other 36V models)
- Garmin Force 36V
- Lowrance Ghost 36V
- Rhodan 36V
- Any other 36V trolling motor
The battery delivers up to 100A of continuous current, which covers common 36V trolling motors, including high-thrust models. GPS features like Minn Kota Spot-Lock and Garmin Anchor Lock work normally; holding position in wind or current makes constant motor corrections and uses more power than steady trolling, so plan capacity around how much you spot-lock.
Good for: bass boats, center consoles, bay boats, walleye and crappie boats, and offshore boats running a 36V bow-mount trolling motor, in freshwater or saltwater.
Runtime
With 100Ah of usable capacity, one Boss Hog is sized for a full day of fishing for most anglers. Exact runtime depends on your motor's power draw, boat size and weight, wind, current, and how much you use spot-lock.
The table below shows approximate, theoretical runtime based on capacity divided by current draw. Real-world runtime will be somewhat lower due to normal system losses and higher draw in wind or current, and longer when trolling at low speed.
| Average motor draw |
Approximate theoretical runtime |
| 10 A |
about 10 hours |
| 20 A |
about 5 hours |
| 40 A |
about 2.5 hours |
| 80 A |
about 1.25 hours |
Most anglers spend the majority of the day at lower speeds, well below full throttle. For long days, big water, or hours of spot-lock, adding a second battery in parallel doubles capacity to 200Ah.
Charging
Here is the one thing to know before your first charge: the Boss Hog is a single 36V battery, so it charges with a 36V lithium charger. This is the most common question when anglers move up from lead-acid.
Your old 3-bank onboard charger will not charge it on its own. A standard 3-bank charger is made to charge three separate 12V batteries. The Boss Hog is one 36V battery with one set of posts, so it needs a charger with a 36V lithium output.
Recommended charger: a 10-amp 36V lithium charger is the practical choice for this battery. It refills the Boss Hog from empty in roughly 10 hours, so a plug-in after your trip has it ready by morning. A 5-amp charger works but takes about twice as long, and higher-output 36V chargers refill faster. If you also run a 12V cranking or electronics battery, Monster Marine Lithium's combination and Dynamic chargers can charge everything from one unit and top off while your outboard runs.
Add Your Charger
The simplest match for the Boss Hog is the 36V 10A Waterproof Lithium Charger, available as an add-on with this battery.
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Right voltage and chemistry. Built for 36V LiFePO4 batteries like the Boss Hog, so it charges to full correctly.
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Full charge in about 10 hours. A 10-amp output refills a fully drained battery overnight.
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Waterproof for onboard use. Can be mounted on the boat and left in place, or used on the bench.
Add the charger to your order so you have everything you need on day one. To charge a cranking or electronics battery from the same unit, ask us about Monster Marine Lithium's combination and Dynamic chargers.
Specifications
Physical
| Weight |
59 lbs |
| Dimensions (L x W x H) |
13.58 in x 7.48 in x 9.65 in |
| Enclosure Material |
Marine-grade ABS housing |
| Terminal Type |
M8 brass bolt |
Electrical
| Nominal Voltage |
38.4 V |
| Nominal Capacity |
100 Ah |
| Energy |
3,840 Wh |
| Charge Voltage Range |
43.5 – 43.8 V |
| Max Charge Current |
50 A |
| Continuous Discharge Current |
100 A max |
| Cycle Life |
4,000+ cycles |
| Battery Chemistry |
Lithium Iron Phosphate (LiFePO4) |
| Bluetooth |
Built-in monitoring via the MMLithium app (iPhone and Android) |
Wiring tip: use appropriately sized marine battery cable for your motor's current, and install an inline fuse or breaker on the positive lead sized to your motor and wiring, following your trolling motor manufacturer's guidance.
Safety and Certifications
The Boss Hog uses Lithium Iron Phosphate (LiFePO4) chemistry, which is far more thermally stable and much less prone to thermal runaway than many other lithium chemistries. Every battery includes an advanced Battery Management System (BMS) that protects against overcharge, over-discharge, over-current, high temperature, and short circuits, with single-cell protection.
Monster Marine Lithium batteries are built and tested to established safety and shipping standards. The list below includes product safety standards, cell-level certifications, quality and environmental management systems, and shipping regulations. Note that "UL listed cells" refers to certification of the cells used inside the battery, not a UL listing of the complete battery.
- UN/DOT 38.3 (shipping)
- 49 CFR 172.704(a) & (3) (transport)
- IATA DGR 1.5.2 & 1.5.2.2(c) (air transport)
- IMDG Code 1.3.1.2 & 1.3.1.4 (sea transport)
- 29 CFR 1910.1200(h)(3)(i)-(iii) (hazard communication)
- UL listed cells (cell-level safety)
- IEC 62133-2017 (cell safety)
- ISO 9001:2008 (quality management system)
- ISO 14001:2004 (environmental management system)
- CE certified
FAQ
Will one Boss Hog last a full day of fishing?
For most anglers, yes. With 100Ah, one Boss Hog is sized for a full day. Actual runtime depends on your motor's draw, boat size, wind, current, and how much you use spot-lock. See the Fits Your Setup tab for approximate figures. If you fish big water, hold spot-lock for hours, or run a heavy boat, adding a second battery in parallel gives extra cushion.
Can I use the 3-bank charger I already have?
Not by itself. A 3-bank charger is built to charge three separate 12V batteries. The Boss Hog is one 36V battery, so it needs a 36V lithium charger, or a combination charger with a 36V lithium bank. A 10-amp 36V lithium charger is the recommended match and is available as an add-on with this battery.
How long does it take to charge?
With the recommended 10-amp 36V charger, a fully drained battery refills in roughly 10 hours, so charging overnight has it ready by morning. A 5-amp charger takes about twice as long, and higher-output 36V chargers are faster.
Will it fit where my three batteries used to go?
Usually with room to spare, since one battery replaces three. The Boss Hog measures 13.58 in long, 7.48 in wide, and 9.65 in tall. Measure your battery compartment against those numbers before installing, and make sure the terminal side lines up with your cable routing.
Can I run two batteries for more time on the water?
Yes. Connect a second Boss Hog in parallel, positive to positive and negative to negative, for 200Ah of total capacity. Running two also adds redundancy: either battery may be able to power the motor on its own if it can be safely isolated with a switch or disconnect. Do not wire two of them in series, as that creates a 72V system your 36V motor is not built for.
Can I use it on a 24V trolling motor?
No. The Boss Hog is a 36V battery for 36V motors. Always match the battery to your motor's voltage. For a 24V motor, you would use a 24V battery instead.
Does the phone app help while fishing?
Yes. The MMLithium app (iPhone and Android) shows your remaining charge, live power draw, and battery health, so you can see how much you have left before committing to a long run or spot-lock.
Can I mount it on its side?
There is no liquid inside a LiFePO4 battery, and Monster Marine Lithium states its batteries can be mounted in any position. Secure the battery firmly so it cannot move, keep the terminals accessible, and follow any orientation notes included with the battery.
Is it waterproof?
It is built for the marine environment and handles spray and wet conditions, but it is not meant to be submerged. Mount it somewhere it will not sit underwater. Monster Marine Lithium's warranty does not cover damage from submersion.
What about cold weather and winter storage?
You can use the battery in the cold, but like all lithium batteries it should not be charged when the battery is below freezing (32°F), since cold charging can damage the cells. In cold weather, let it warm above freezing before charging or keep it warmer than the outside air. For winter, Monster Marine Lithium recommends fully charging the battery, removing it from the boat, and storing it somewhere temperature-controlled, then recharging every 30 to 60 days.
What warranty does it come with?
A 15-year tiered warranty from Monster Marine Lithium. Tier 1 (years 0 to 5): defects replaced or repaired free of parts and labor, no cycle limit. Tier 2 (years 5 to 10): free repair with a 2,000-cycle limit; if not repairable, a 50% prorate is offered to the original purchaser. Tier 3 (years 10 to 15): repair with the owner paying parts; if not repairable, replacement at 30% off current MSRP, with a 2,500-cycle limit. Register within 60 days of purchase. Non-transferable; lower 48 states. For full details read the Warranty Tab
