Sodium-Ion Marine Battery Technology

The Four Marine Energy Problems

Every marine energy system has to solve four problems at once. Most chemistries solve one or two. Sodium-ion solves all four.

Problem 1: Fire

Lithium-ion and LiFePO4 can experience thermal runaway — a self-sustaining exothermic reaction that produces fire, toxic gas, and explosion risk. On a boat, there's nowhere to go.

Na-Ion Solution: Sodium-ion chemistry cannot enter thermal runaway. The electrochemical mechanism simply doesn't support the runaway cascade. Zero fire risk. Insurers treat it identically to lead-acid.

Problem 2: Temperature

Florida engine rooms exceed 50°C in summer. Standard LiFePO4 is rated to 45°C and derates above it. Lead-acid loses capacity below 10°C. Marine environments are brutal on both.

Na-Ion Solution: Sodium-ion operates from -20°C to 60°C with no derating. No climate-controlled compartment needed. Full rated capacity in Florida heat and northern cold alike.

Problem 3: Surge

Gyroscopic stabilizers demand 3–5× their steady-state draw during spin-up — 10–25 kW for 2–4 seconds. Most batteries sag under this surge, causing BMS protection trips and failed starts.

Na-Ion Solution: Sodium-ion has excellent high-rate discharge capability. Our SALT START™ packs are engineered specifically for stabilizer surge profiles — tested against actual SK6 through SK35 inrush curves.

Problem 4: Longevity

Lead-acid lasts 500 cycles. LiFePO4 lasts ~2,000. On a boat used 200 days a year, you're replacing lead-acid every 2–3 years. The replacement cost erases any upfront savings.

Na-Ion Solution: 3,000+ cycle life at 80% DoD. At 200 cycles/year, that's 15+ years before degradation. The math is simple: sodium-ion is cheaper over the system lifecycle.

Chemistry Comparison

Property	Na-Ion (SALT START™)	LiFePO4 (lithium)	Lead-Acid AGM
Thermal Runaway Risk	None	Possible	Very Low
Cycle Life (to 80%)	3,000+	~2,000	~500
Operating Temp Range	-20°C to 60°C	0°C to 45°C	-20°C to 50°C
Weight (per kWh)	~12 kg	~10 kg	~30 kg
High-Surge Capability	Excellent	Good	Fair
Marine Insurance	No issues	Varies by insurer	Standard
Engine Room (50°C)	Full capacity	Derates	Accelerated aging
10-Year Total Cost	Lowest	Medium	Highest

Source: STAR internal testing + Seakeeper Battery Sizing TB-90621-3 + manufacturer datasheets. Marine environment conditions assumed.

SALT START™ Technology

Engineered by Salty Marine · Developed under STAR R&D

SALT START™ is not a commodity sodium-ion product. It's an engineered system designed from scratch for marine stabilizer applications.

Surge-Tuned Cell Selection

Cells are selected and qualified specifically for the 3–5× inrush current profile of marine gyro startup. Not all sodium-ion cells are surge-rated — ours are.

Marine-Grade BMS

IP67-rated battery management system with salt-spray resistant housing. Monitors cell voltage, temperature, current, and state-of-charge in real time. No consumer-grade electronics in a bilge.

Load-Matched Sizing

Every SALT START™ pack is sized to the specific stabilizer model and vessel house load. We don't sell boxes off a shelf. We engineer systems for your vessel's actual power profile.

Sodium-Ion Technology