Introduction
Most yacht owners I’ve met fall into two camps: those who rely on their lead-acid batteries and those who switched to lithium—often reluctantly. But both still face the same core problems: excessive weight, bulky size, and fire risk.
Lead-acid batteries weigh over 30 kg and take up too much space. They underperform in cold conditions and demand constant maintenance. Lithium-ion (LiFePO4) batteries weigh less but carry thermal runaway risks. And in a marine environment, a fire means real danger—not just inconvenience.
Sodium-ion batteries provide a safer, more cost-effective alternative. They remain stable, perform well in cold temperatures, and avoid the resource and geopolitical issues tied to lithium and cobalt.
Five years ago, I wouldn’t have recommended sodium. Today, I’ve seen it power boat after boat—especially when owners replaced aging AGMs.
12v 100Ah Sodium ion battery
12V 100Ah Sodium-Ion Battery: Core Specs That Matter for Yachts
Let’s get technical. Here are the specs that matter most onboard:
| Parameter | Value | Notes |
|---|
| Nominal Voltage | 12V | Works with most marine DC systems |
| Nominal Capacity | 100Ah | Standard replacement size |
| Energy | 1200Wh | Offers higher usable energy than AGM |
| Dimensions (L×W×H) | 363 × 212 × 230 mm | Check your battery compartment size |
| Weight | ~13.5 kg | Weighs 50% less than AGM |
| Charge Temp Range | -20°C to 70°C | Suitable for year-round cruising |
| Discharge Temp Range | -40°C to 70°C | Operates well even in freezing climates |
| Max Continuous Discharge | 100A | Powers large loads |
| Cycle Life | 4000 cycles | Provides 8–10 years of typical weekend use |
| Protection | Built-in BMS | Guards against over-voltage, temperature, and short circuits |
| Water/Dust Resistance | Splash-proof (IP65) | Handles bilge or salt spray areas |
Charge and Discharge Details
- We recommend charging at 10A (-20℃ to -10℃), 20A (-10℃ to 0℃), and allow up to 50A max above 0℃.
- The battery supports 150A pulse current for under 3 milliseconds, sufficient for engine start assist or surge loads.
- The BMS cuts off discharge at 8V to prevent deep discharge damage.
- Self-discharge remains low at ≤3.5% per month at 25℃, outperforming many lead-acid types.
Battery Fit Guide: What Can It Replace?
Use the table below to compare the sodium-ion battery against common marine battery types:
| Battery Type | Size (mm) | Weight (kg) | Voltage | Replaceable by Sodium? | Notes |
|---|
| Lead-acid AGM | 350 × 180 × 235 | ~30 | 12V | Yes | Sodium offers a lighter, safer swap |
| GEL | 330 × 175 × 240 | ~28 | 12V | Yes | Slightly smaller footprint |
| LiFePO4 | 330 × 172 × 220 | ~13 | 12.8V | Yes | Tolerates slight voltage variation |
| Sodium-ion (new) | 363 × 212 × 230 | ~13.5 | 12V | — | Compact, safe, and drop-in compatible |
Pro Tip: Ensure your battery box measures at least 370 × 220 × 250 mm. If not, consult us for custom-fit options.
Which Yachts Benefit Most from This Battery?
| Yacht Size | Example Models | Typical Electrical Load | Recommended Setup |
|---|
| 18–25 ft | Boston Whaler 240, Robalo 22 | Lights, sonar, live well, GPS | 1x 12V 100Ah |
| 26–35 ft | Jeanneau 32, Bayliner 285 | Fridge, nav, LED, bilge, light inverter | 2x 12V 100Ah (parallel) |
| 36–45 ft | Catalina 38, Bavaria 40 | Microwave, water pump, audio, radar | 3–4x 12V 100Ah (parallel) |
Owners typically complete installation in less than an hour if they maintain clean cables and terminals.
North America vs. Europe Yacht Storage Constraints
Battery fit depends on your boat’s country of origin. Here’s a practical size-matching reference by region:
| Region | Common Boat Sizes | Typical Battery Locker Size (mm) | Sodium Fit (363×212×230mm) | Notes |
|---|
| North America | 25–35 ft | 400×250×250 | Fits most locker layouts | Bayliner, Hunter, Catalina |
| Europe | 24–32 ft | 360×220×240 | Fits but snugly | Jeanneau, Bavaria, Beneteau |
| Nordic | 20–28 ft compact cruisers | 330×210×200 | Custom fit may be necessary | Ask about reduced-height versions |
Scenario Insight:
- Mike from Florida upgraded a 34ft Hunter with 2x sodium batteries, reducing locker weight by 40 kg.
- Sven from Germany customized a low-profile casing for his 26ft Bavaria’s narrow locker.
Real-World Upgrade: Case Study
Mike from Clearwater, FL owned a 34ft Hunter running 2x AGM batteries. After switching to 2x sodium-ion units:
| Metric | AGM (Old Setup) | Sodium-Ion (New Setup) |
|---|
| Total Weight | 60 kg | 27 kg |
| Locker Space Used | 100% | 70% |
| Fridge Runtime (1x100Ah) | 10 hrs | 18 hrs |
| Maintenance Required | Monthly checks | None |
Mike shared, “I didn’t just save space—I gained reliability and peace of mind.”
Realistic Use Scenarios and Power Calculations
Scenario 1: Port Standby Mode (No Shore Power)
Typical loads include:
| Device | Power (W) | Usage (hrs) | Total Wh |
|---|
| Refrigerator | 45 | 12 | 540 |
| LED Lighting | 20 | 8 | 160 |
| Bilge Pump | 30 | 0.5 | 15 |
| Ventilation Fan | 25 | 8 | 200 |
| Total Daily Energy | | | 915 Wh |
A single 12V 100Ah sodium battery (1200Wh usable) supports roughly 1 day of port standby without shore power.
Scenario 2: Offshore Anchor 24-hour Power Budget
Typical loads include:
| Device | Power (W) | Usage (hrs) | Total Wh |
|---|
| Navigation Lights | 25 | 12 | 300 |
| VHF Radio | 10 | 10 | 100 |
| GPS System | 10 | 10 | 100 |
| Refrigerator | 45 | 18 | 810 |
| Bilge Pump | 30 | 1 | 30 |
| Cabin Lights | 20 | 6 | 120 |
| Water Pump | 40 | 0.5 | 20 |
| Total Daily Energy | | | 1480 Wh |
Two sodium batteries in parallel (2400Wh) provide a comfortable 24-hour anchor power reserve.
Power System Recommendations
| Item | Recommendation | Notes |
|---|
| Inverter Size | 500W to 1000W | Based on peak AC loads (microwave, tools) |
| Charge Controller | MPPT with 15.6V cutoff | Matches sodium battery max voltage |
| Cabling | Minimum 6 AWG for 50A continuous current | Use marine-grade tinned copper; keep cable runs short |
| Battery Management | Built-in smart BMS | Protects against overcharge, over-discharge, current, and temperature |
| Parallel Setup | Up to 4 batteries in parallel tested | Use balanced wiring and proper fusing |
Environmental Adaptability: Saltwater vs Freshwater & Climate Considerations
- Sodium-ion battery casings use marine-grade plastic with IP65 splash protection, which resists salt spray corrosion better than exposed metal terminals common in lead-acid.
- In saltwater environments, owners should regularly inspect terminals and apply anti-corrosion sprays.
- Sodium batteries operate reliably between -40°C to 70°C, outperforming lead-acid in cold northern lakes and resisting thermal degradation in hot southern climates like Florida.
- For high humidity tropical environments, proper locker ventilation plus marine insulation helps reduce condensation risks.
Transitioning from AGM or LiFePO4: What to Expect
| Feature | Sodium-Ion Compatibility | Notes |
|---|
| Terminal Type | Standard M8 | Direct swap; owners should monitor terminal corrosion |
| Charger Voltage | Max 15.6V | Use marine chargers rated 14.6–15.6V |
| Charging Current | Recommended 10–20A, max 50A | Reduce current charging below 0°C |
| Discharging Current | Up to 100A continuous, 150A pulse | Supports high starting current loads |
| Mounting Position | Any orientation | No venting required; mount flat, vertical, or angled |
| Solar Compatibility | Yes, MPPT cutoff voltage adjustable | Keep max voltage below 15.6V |
Conclusion
The 12V 100Ah Sodium-ion battery delivers a practical and dependable solution for yacht owners seeking to upgrade from traditional AGM or lithium options. With its fire-safe chemistry, reliable cold-weather performance, and longer runtime in a lighter, compact form, it supports essential onboard systems without the maintenance hassle. Built to fit most yacht battery lockers and withstand marine environments, it ensures worry-free operation during every journey—whether docked or at anchor.
Need a custom sodium battery solution for your yacht? Contact Kamada Power today to design a battery that fits your exact dimensions and performance needs.
FAQ
Q1: What if my boat uses LiFePO4 — can I still switch?
Yes. Just ensure your charger stays below 15.6V and your compartment fits 363 x 212 x 230 mm.
Q2: Is sodium-ion safe in saltwater environments?
Absolutely. It has IP65 splash-proof protection and won’t catch fire.
Q3: What happens if I don’t charge for months?
No problem. The battery self-discharges slowly—≤3.5% per month—and can stay idle for 6+ months.
Q4: Can I use it with solar?
Yes. Just configure your charge controller below 15.6V. Most MPPT controllers allow custom cutoffs.
Q5: Will it fit my battery box?
Measure first. If your box exceeds 363 x 212 x 230 mm, it fits perfectly.