The Monster Marine Lithium "Titan" (model MML-CW3675B) is a 36V 75Ah Bluetooth deep cycle LiFePO4 trolling motor battery, sold by Lithium Battery Supply. One Titan replaces a three-battery 36-volt lead-acid bank with a single 42-pound lithium battery, so you clear out two battery boxes and the series jumper cables while dropping significant weight from the bow.
It delivers 2,880 Wh of energy from Lithium Iron Phosphate (LiFePO4) cells and holds a flat voltage under load, so your motor pulls the same power from the first cast to the last instead of fading like lead-acid. Built-in Bluetooth reports voltage, current, remaining capacity, and battery health to your phone, so you always know how much trolling time is left before the run back to the ramp.
The Titan is a deep cycle trolling battery designed for 36V trolling motors from Minn Kota, Garmin, Lowrance, Rhodan, and other brands. It is not a cranking battery for starting an outboard.
Titan vs. a three-battery lead-acid 36V bank
|
Titan (one battery) |
Three 12V lead-acid batteries |
| Batteries needed |
1 |
3, wired in series |
| Approx. weight |
42 lbs |
Commonly 100+ lbs combined |
| Voltage under load |
Flat curve, steady power |
Sags as it drains |
| Cycle life |
4,000+ cycles |
Far fewer; varies by type and care |
| Monitoring |
Bluetooth app |
None built in |
Features and Benefits
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One battery replaces a three-battery 36V bank: a single Titan does the job of three 12V batteries wired in series, so you free up two battery boxes and simplify the wiring at the bow.
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Lightweight at 42 pounds: a comparable three-battery lead-acid 36V bank commonly runs well over 100 pounds. Shedding that weight up front can help planing and handling, and makes battery removal a one-person job.
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Flat LiFePO4 discharge curve: Lithium Iron Phosphate holds voltage steady as it drains, so your trolling speed and electronics stay consistent deep into the charge instead of fading like lead-acid.
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4,000-plus cycle life: rated for over 4,000 charge cycles, far beyond the typical service life of a lead-acid trolling bank, which lowers your long-term cost per season.
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Bluetooth monitoring: the MMLithium app (iOS and Android) shows real-time voltage, current draw, remaining capacity, and battery health, so you plan your day around actual power left, not a guess.
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Expandable capacity: add a second Titan in parallel (positive to positive, negative to negative) to increase amp-hour capacity for longer days in heavy current while keeping the system at 36 volts.
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Plug-and-play wiring: connect your 36V trolling motor leads directly to the M8 brass terminals. Because it is already a 36-volt battery, there is no series bank to build.
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Smart BMS protection: the built-in battery management system guards against overcharge, over-discharge, over-current, short circuit, and high temperature, shutting the battery down before damage occurs.
Compatibility and Fitment
Trolling motors: The Titan is built for 36V trolling motors and is compatible with Minn Kota, Garmin, Lowrance, and Rhodan, as well as other 36-volt trolling motors. It has a 100A continuous discharge rating. Maximum current draw varies by motor model, so check your motor's maximum amp draw in its manual and confirm it stays below 100A; common 36V bow-mount trolling motors fall well within that limit, so a single Titan can drive the motor on its own.
Wiring, read this if you are switching from a lead-acid bank: The Titan is a single 36-volt battery. Do not wire it in series the way you wired three 12V batteries. Connect the trolling motor's positive and negative leads straight to the Titan's terminals. To add run time, connect a second Titan in parallel (positive to positive, negative to negative); this keeps the voltage at 36V and adds amp-hours.
Physical fit: The Titan is built in a Group 31 case and measures 13 in (L) x 6.77 in (W) x 9.5 in (H), so it drops into a standard Group 31 tray where your old batteries sat. Because you are going from three cases to one, you also free up space. Measure the height clearance of your battery box or compartment lid against the 9.5 in dimension before ordering, since some enclosed trays are cut close.
Terminals: M8 brass bolt terminals. Use the correct ring terminals and do not overtighten.
Not for engine starting: The Titan is a deep cycle trolling battery, not a cranking battery. Use a dedicated cranking battery to start your outboard.
Suitable for boats running a 36V trolling motor, including:
- Bass boats
- Bay boats and flats skiffs
- Center consoles
- Aluminum fishing boats and jon boats
- Walleye and multi-species boats
- Offshore boats using a 36V bow-mount trolling motor
If your boat runs a 36-volt trolling motor from Minn Kota, Garmin, Lowrance, Rhodan, or another brand, the Titan is designed to power it. For engine starting or 12V house loads, pair it with a separate cranking or dual-purpose battery.
Charging
Use a lithium-compatible charger. Charge the Titan with a charger that has a LiFePO4 (lithium) profile, or a charger with a selectable profile that keeps output within the battery's charge voltage range of 43.5 to 43.8 volts for the 36V system. The maximum charge current is 50A.
Do not use lead-acid desulfation or equalization modes. Charge modes that pulse high voltage to recondition lead-acid batteries can push the pack outside its safe range. If your on-board charger has an AGM setting and no dedicated lithium setting, confirm the AGM profile stays within the charge voltage range above before relying on it. Monster Marine Lithium notes that many chargers on the market lack the features to properly maintain and wake lithium batteries, which is why they offer chargers designed for these packs.
Charging in the cold. The battery can still discharge and run your motor in cold weather, though very low temperatures can reduce available capacity and performance. Charging below freezing can damage lithium cells, so the battery management system blocks charging until the pack warms to a safe temperature. Plan to charge indoors or in a garage when temperatures are near or below freezing.
Charging from the engine or alternator: If you intend to charge while running, confirm your charging source's regulated output voltage stays within the battery's charge range, and use a DC-to-DC charger with a lithium profile rather than connecting the pack directly to an alternator.
Specifications
| Model |
MML-CW3675B |
| Battery type |
Deep cycle trolling motor battery |
| Battery chemistry |
Lithium Iron Phosphate (LiFePO4) |
| Nominal voltage |
38.4 V (36V system) |
| Nominal capacity |
75 Ah |
| Energy |
2,880 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 |
| Weight |
42 lbs |
| Case size |
Group 31 |
| Dimensions (L x W x H) |
13 in x 6.77 in x 9.5 in (330 x 172 x 241 mm) |
| Enclosure material |
Marine-grade ABS housing |
| Terminal type |
M8 brass bolt |
| Bluetooth |
Built-in smart monitoring via the MMLithium app (iOS and Android) |
| Certifications |
UN/DOT 38.3; UL listed cells; IEC 62133-2017; ISO 9001:2008; ISO 14001:2004; CE |
| Warranty |
15-year limited (Tier 1, years 0–5, free replacement) |
| Primary use |
36V trolling motors (Minn Kota, Garmin, Lowrance, Rhodan, and other 36V motors) |
| Replaces |
Three 12V SLA batteries wired for 36V |
Note: Monster Marine Lithium does not publish an IP water-ingress rating for this model, so none is listed above.
Safety and Certifications
The Titan uses Lithium Iron Phosphate (LiFePO4) chemistry, chosen for its stability and safety, and is managed by an advanced battery management system that guards against overcharge, over-discharge, over-current, short circuit, and high temperature. Monster Marine Lithium tests its batteries to stringent standards, and MML batteries are certified for use across a wide range of applications and conform to UN/DOT 38.3 shipping regulations.
Certifications and standards
- UN/DOT 38.3 (transport safety)
- 49 CFR 172.704(a) & (3)
- IATA DGR 1.5.2 & 1.5.2.2(c)
- IMDG Code 1.3.1.2 & 1.3.1.4
- 29 CFR 1910.1200(h)(3)(i)-(iii)
- UL listed cells
- IEC 62133-2017 (safety)
- ISO 9001:2008 (quality management)
- ISO 14001:2004 (environmental management)
- CE certified
Note on UL: the cells inside the battery are UL listed. This refers to the cells, not a UL listing of the complete battery pack.
FAQ
Will one Titan really replace my three 12V trolling batteries?
Yes. The Titan is a single 36-volt battery, so it does the job of three 12V batteries wired in series. You remove two battery boxes and the series jumper cables, and you can save roughly 100 pounds or more compared with many three-battery lead-acid banks.
Do I wire it in series like my old three-battery setup?
No. The Titan is already 36 volts, so there is no series bank to build. Run your trolling motor's positive and negative leads directly to the battery terminals. If you want more run time, add a second Titan in parallel (positive to positive, negative to negative), which keeps the system at 36V and adds capacity.
How long will it run my 36V trolling motor?
Run time depends on your average current draw, which changes with speed, wind, current, and boat weight. As a rough guide, divide the 75Ah capacity by your average draw. The estimates below are approximate and assume steady draw, not real-world spikes.
| Average draw |
Typical use |
Approx. run time |
| 10 A |
Spot-lock, light trolling |
~7.5 hours |
| 20 A |
Moderate cruising |
~3.75 hours |
| 40 A |
High thrust / heavy current |
~1.9 hours |
The Bluetooth app shows your real-time draw so you can manage the day and add a second Titan in parallel if you routinely fish heavy current.
Will it power my Minn Kota, Garmin, Lowrance, or Rhodan motor?
Yes. The Titan is compatible with 36V trolling motors from Minn Kota, Garmin, Lowrance, and Rhodan, as well as other 36-volt motors. It has a 100A continuous discharge rating. Because maximum draw varies by motor, check your motor's maximum amp draw in its manual and confirm it is below 100A; common 36V bow-mount motors fall well within that limit, so a single Titan can run the motor on its own.
What charger do I need, and can I use my old lead-acid or AGM on-board charger?
Use a charger with a lithium (LiFePO4) profile, or one whose selected profile stays within the 43.5 to 43.8 volt charge range for this 36V battery, at up to 50A. Do not use lead-acid desulfation or equalization modes, which pulse high voltage and can push the pack out of its safe range. If your on-board charger only offers an AGM setting, confirm that profile stays within the charge voltage range before relying on it. Monster Marine Lithium offers chargers designed to charge, maintain, and wake lithium packs, since many older chargers lack those features.
Can I charge it in cold weather?
Yes, with one caveat. The battery still discharges and runs your motor in the cold, though very low temperatures can reduce available capacity and performance. Charging below freezing can damage lithium cells, so the battery management system blocks charging until the pack warms to a safe temperature. When it is near or below freezing, charge the battery indoors or in a garage.
Is it waterproof? Can it get rained on?
The Titan uses a marine-grade ABS housing built for the boat environment. As with any marine battery, keep the terminals protected and clean, and mount it in a battery box or a compartment that is not sitting in standing water. Monster Marine Lithium does not publish a specific water-ingress (IP) rating for this model.
Will it fit my battery tray?
The Titan measures 13 x 6.77 x 9.5 inches. The length and width match a standard Group 31 footprint, so it sits where your old batteries did. Because you are going from three cases to one, you gain space. Check that your box or compartment lid clears the 9.5 inch height before ordering.
How much weight will I save?
The Titan weighs 42 pounds. A three-battery lead-acid 36V bank commonly weighs well over 100 pounds combined, so many anglers save roughly 100 pounds or more, depending on the batteries being replaced. Less weight up front can help planing and handling and makes lifting the battery out for charging or storage far easier.
What does the Bluetooth app do?
The MMLithium app for iOS and Android connects to the battery over Bluetooth and shows real-time voltage, current draw, remaining capacity, and battery health, so you can see how much trolling time is left rather than guessing.
Can I add a second battery for more run time?
Yes. Connect a second Titan in parallel, positive to positive and negative to negative. This keeps the system at 36 volts and roughly doubles the amp-hour capacity for longer days in heavy current.
Can I use it to start my outboard engine?
No. The Titan is a deep cycle trolling battery, not a cranking battery. Use a dedicated cranking or dual-purpose battery to start your outboard.
What is the warranty?
Monster Marine Lithium backs the Titan with a 15-year limited warranty structured in tiers. Under Tier 1, years 0 through 5, a battery with a manufacturing defect is replaced at no cost with no charge-cycle limit. Tiers 2 and 3 provide coverage in years 5 to 10 and 10 to 15. Register the battery within 60 days of purchase to secure full coverage. Read our Warranty Tab.
How do I store it in the off-season?
Fully charge the battery before storage, then disconnect it and keep it in a temperature-controlled space. A small parasitic draw exists even in storage, so use maintenance charging or top the battery off periodically. Letting a lithium battery sit uncharged for long periods is the most common cause of avoidable damage.
