Marine Lithium Batteries for Boats & Trolling Motors
Power your boat, trolling motor and onboard electronics with deep-cycle LiFePO4 marine batteries that are lighter, last longer and charge faster than traditional marine lead-acid batteries.
SAFTEC marine lithium batteries are designed as:
Deep-cycle batteries for trolling motors
House / auxiliary batteries for onboard electronics
General 12V / 24V / 36V marine power systems
Marine Lithium Battery Manufacturer – SAFTEC
What battery we offer:
- Standard 12V / 24V / 36V deep-cycle LiFePO4 packs for marine use
- OEM / ODM battery packs tailored to boat builders and system integrators
- Complete packs: cells + BMS + IP-rated enclosure + cabling + terminals
- Optional cell-ready packs (pack structure + BMS; you specify or supply cells)
- Design support for vibration, moisture, limited space and cable routing in marine installations
Boat & Marine Applications We Support
SAFTEC marine LiFePO4 deep-cycle batteries are designed for:
Trolling motors and electric propulsion
Freshwater and inshore fishing boats
Bow-mount trolling motors
Smaller electric outboard systems
House banks and cabin power
Sailboats, cabin cruisers and small yachts
Loads such as lights, navigation, chartplotters, sonar, refrigeration, water pumps and audio
Electronics and auxiliary systems
Dedicated power for electronics on workboats and patrol boats
Auxiliary 12V / 24V systems for winches, bow thrusters or specialized equipment (when correctly sized)
Which Marine Lithium Range Do You Need?
SAFTEC marine lithium batteries are built around the most common DC bus voltages used on boats (customization available):
| Model | Nominal V | Capacity (Ah) | Max Cont. Discharge (A) | Max Charge (A) | Peak (Duration) | Group / Dimensions (mm / in) | Weight (kg / lb) |
|---|---|---|---|---|---|---|---|
| 12V75-BL | 12.8 | 75 | 75 | 75 | 160A / 3s | G24 · 260×168×211 | 9.6 / 21.1 |
| 12V100-BL | 12.8 | 100 | 100 | 100 | 200A / 3s | G27 · 307×168×221 | 12.2 / 26.9 |
| 24V40-BL | 25.6 | 40 | 40 | 40 | 80A / 3s | G24 · 260×168×221 | 9.4 / 20.7 |
| 24V50-BL | 25.6 | 50 | 50 | 50 | 100A / 3s | G31 · 329×172×223 | 12.2 / 26.8 |
| 36V40-BL | 38.4 | 40 | 40 | 40 | 80A / 3s | G31 · 329×172×223 | 13.7 / 30.2 |
| 48V200-ST | 51.2 | 200 | 160 | 200 | 250A / 5s | 867×358×393 | 137 / 302 |
| 48V200-LT | 51.2 | 200 | 160 | 200 | 400A / 2s | 1005×460×305 · 39.5×18.1×12.0 | 105 / 231.4 |
| 48V300-ST | 51.2 | 300 | 200 | 200 | 250A / 5s | 740×506×408 · 29.1×19.9×16.0 | 176 / 388 |
How to Work With SAFTEC on Your Marine Battery Project
SAFTEC supports both single-project upgrades and OEM marine programs.
1. Understand your boat & loads
- System voltage (12 / 24 / 36 V) & trolling motor power
- Main house loads and target runtime
- Mounting location, space and cabling constraints
2. Propose a technical solution
Recommended voltage, capacity and pack quantity
- Draft enclosure, terminals and connection layout
3. Scale to production
Pilot batch for final validation
Stable serial production, batch traceability & technical support
Why Switch from Lead-Acid to LiFePO4?
If your boat still uses flooded or AGM deep-cycle marine batteries, switching to LiFePO4 can solve the most common pain points.
Longer cycle life
- Flooded / AGM deep-cycle: typically a few hundred deep cycles
- LiFePO4: commonly 2,000–4,000+ cycles at 80% DoD
More usable capacity
Lead-acid: practical usable capacity ≈ 50% of rated Ah
LiFePO4: practical usable capacity 80–100% of rated Ah
Lower weight and better handling
- LiFePO4 marine batteries are typically 40–60% lighter than equivalent lead-acid batteries
- Easier to lift and install, less stern or bow weight, more flexible placement
Stable voltage and low maintenance
Less voltage sag under load, so trolling motors, sonar, and electronics perform more consistently
No acid, no topping up, no corrosion to clean up
Learn More About Marine Batteries:
What Is a Marine Lithium Battery and How Is It Different from a Car Battery?
A marine lithium battery is designed to power a boat in a harsh, wet, constantly vibrating environment. That makes it very different from an ordinary car battery, even if the voltage and capacity numbers look similar on paper.
Car batteries are built for short bursts.
An automotive starter battery is optimised to deliver a very high cranking current for a few seconds, then it is quickly recharged by the alternator and kept near 100% state of charge. It is not expected to sit deep-discharged, or to deliver power for hours at a time.
Marine batteries must survive deep discharge and constant motion.
On a boat, the battery may be running trolling motors, fish finders, radios, lights, pumps and electronics for many hours. It will see regular deep discharges, continuous vibration, and sometimes long storage periods. A marine lithium battery is engineered for:
Deeper usable capacity – typically up to 80–90% depth of discharge without damaging the cells.
Flat voltage curve – keeps your trolling motor or electronics running at consistent power.
High cycle life – thousands of cycles when used correctly, so you are not replacing batteries every season.
Mechanical robustness – secure internal busbars, cell fixing and foam, so the pack can handle waves and pounding.
Extra protection against water and corrosion.
If you are currently using adapted car or truck batteries on your boat, upgrading to a dedicated marine lithium pack will typically give you:
Longer runtime for the same Ah rating
Less voltage sag under load
Much lower maintenance and replacement cost over the life of the boat
Not sure where to start? Send us your boat type, trolling motor model and desired run time, and SAFTEC can recommend a marine lithium configuration.
How to Choose Voltage & Capacity for Your Boat
This section gives a short selection guide
1. Confirm your system voltage
12V – small craft, basic 12V trolling motors, simple house loads
24V – mid-size trolling motors, larger house systems
36V – high-thrust trolling motors and some electric propulsion setups
Your battery voltage must match the trolling motor and onboard DC system specifications.
2. Estimate your daily energy use
List main loads (trolling motor, electronics, fridge, pumps, lights, audio).
Estimate their power (W) and runtime (hours).
Multiply and add them to get daily Wh (watt-hours).
Example:
Trolling motor: 600 W × 4 h = 2,400 Wh
Electronics and lights: 100 W × 4 h = 400 Wh
Total ≈ 2,800 Wh per day
To convert to Ah:
At 12V: 2,800 Wh ÷ 12 V ≈ 233 Ah
At 24V: 2,800 Wh ÷ 24 V ≈ 117 Ah
At 36V: 2,800 Wh ÷ 36 V ≈ 78 Ah
3. Add a safety margin
Size the battery with a margin to cover wind, current, and extra loads:
For the 12V example above (≈233 Ah needed), a practical recommendation might be:
2 × 12V 120Ah in parallel, or
1 × 12V 280–300Ah pack, depending on space and weight.
4. Check current ratings and physical fit
Confirm the pack’s continuous and peak discharge current covers your trolling motor and house loads.
Check dimensions and mounting against your battery box or compartment.
Confirm terminal type and orientation suit your cabling.
Not sure where to start? Send us your boat type, trolling motor model and desired run time, and SAFTEC can recommend a marine lithium configuration.
Which Marine Battery Setup Do You Really Need?
Choosing a marine battery is less about brand names and more about how you actually use the boat
1. Trolling-motor focused fishing boat
Typical boat: Bass boat or small fishing boat with an electric trolling motor in the bow.
Loads: Trolling motor + basic electronics (fish finder, navigation, lights).
Recommended setup:
24V or 36V lithium battery bank sized for your motor thrust and typical fishing day
Separate small starter battery for the outboard if needed
What lithium gives you: Stable thrust all day without the “dying” feeling after a few hours, and much lower weight in the bow.
2. Day cruiser with house loads
Typical boat: Runabout or cabin boat used for day trips.
Loads: Lights, pumps, sound system, small inverter, fridge, electronics.
Recommended setup:
12V lithium “house bank” for all DC loads
Separate starting battery (AGM or lithium) for the engine
What lithium gives you: Longer time at anchor without worrying about draining the starter battery, and very fast recharge when you run the engine or connect shore power.
3. Multi-day or offshore boat
Typical boat: Larger fishing boat or cruiser used for multi-day trips.
Loads: Everything above, plus heavier inverters and navigation equipment.
Recommended setup:
One or more lithium house banks sized from your daily energy budget
Redundant charging sources (alternator, shore charger, solar or generator)
What lithium gives you: A lighter boat, more usable capacity from the same footprint, and much longer battery life under continuous cycling.
If you send SAFTEC your boat length, motor size, typical fishing/usage hours and existing battery space, we can help you choose the right voltage (12V / 24V / 36V), capacity and number of packs for your setup.
Not sure where to start? Send us your boat type, trolling motor model and desired run time, and SAFTEC can recommend a marine lithium configuration.
Charging & Safety for Marine Lithium Batteries
LiFePO4 marine batteries are straightforward to charge as long as the charger is compatible and correctly configured.
Charger compatibility
Best options:
Marine onboard chargers with a “Lithium” / “LiFePO4” profile, or
Programmable smart chargers set to suitable LiFePO4 voltages
For a typical 12V LiFePO4 pack:
Bulk/absorption: around 14.4–14.6 V
Float (if used): around 13.6–13.8 V, or no float depending on system design
Old-style chargers designed only for flooded batteries, especially those with aggressive equalization or high float voltages, are not recommended
Basic safety and installation guidelines
Use marine-grade cables, lugs and fuses sized for maximum current
Protect cables from abrasion and support them properly
Install batteries in locations appropriate to their IP rating
Avoid extreme engine-bay temperatures unless the pack is specifically rated for that environment
Follow BMS warnings and do not bypass protections
Every SAFTEC marine lithium pack includes a built-in BMS for over-charge, over-discharge, over-current and temperature protection within the designed operating range.
Testing, Certifications & Warranty at SAFTEC
Marine environments are harsh. SAFTEC designs and validates marine lithium packs with this reality in mind.
Electrical and functional testing
Capacity and internal resistance verification
BMS protection thresholds and contactor operation
Charge / discharge performance at rated currents
Mechanical and environmental focus
Robust mechanical structure and mounting points for vibration and shock
Enclosures and seals selected to meet project-specific IP rating targets
Design practices that consider humidity and potential spray
Certifications and documentation (project-dependent)
UN38.3 for transport safety
Relevant IEC / EN standards for industrial rechargeable lithium batteries as required
Regional compliance (e.g. CE) where applicable
Warranty
Multi-year limited warranty options, aligned with application and duty cycle
Clear definition of expected service life, operating limits and usage assumptions during project scoping
Marine Lithium Battery FAQs
Can I use SAFTEC marine lithium batteries to start my engine?
No. SAFTEC marine LiFePO4 packs are designed as deep-cycle batteries for trolling motors, house banks and electronics. For engine starting, we recommend a dedicated starting battery designed for cranking duty.
Do I need to replace my existing onboard charger?
If your charger has a LiFePO4 / Lithium mode or can be configured to suitable LiFePO4 voltages, it may be compatible. Older chargers designed only for flooded batteries, especially with aggressive equalization or high float voltages, are usually not suitable. Share your charger model and specs with SAFTEC and we can advise.
How long do marine lithium batteries last?
In typical recreational use, a well-sized LiFePO4 marine battery can last many seasons, often 8–10 years or more. Actual life depends on how often you cycle the battery, how deeply you discharge it, how it is charged and the temperatures it sees in service.
Can I use lithium and lead-acid batteries on the same boat?
Yes, as long as they are used in separate banks with appropriate charging. For example, you can keep a lead-acid starting battery for the engine and use LiFePO4 batteries for trolling and house loads. Do not parallel lithium and lead-acid batteries directly in the same bank.
What information should I provide for a quote?
To size a system, SAFTEC needs at least: boat type and length, system voltage (12 / 24 / 36V), trolling motor model and power, estimated daily runtime, main 12V/24V loads, and where you plan to install the battery. With this information we can recommend a specific marine lithium configuration and quote accordingly.
