Frequently Asked Questions
Why do superyachts need dedicated lithium battery storage?
Modern superyachts carry multiple lithium systems: e-foils (5–10 kWh), seabobs (2–4 kWh), drones, jetboards, and backup electronics. These systems generate heat during charge cycles and can experience thermal runaway if damaged, short-circuited, or exposed to extreme temperatures. Dedicated containment prevents fire propagation to fuel tanks, crew quarters, and critical systems. Classification societies and flag states increasingly require this equipment; insurance may not cover claims without proper storage protocols.
What is thermal runaway and why is it dangerous on vessels?
Thermal runaway is a rapid, self-sustaining exothermic reaction where internal battery temperature and pressure escalate uncontrollably, often in seconds. It generates extreme heat (over 900°C / 1650°F), flammable gases, and toxic emissions. Manufacturers estimate thermal runaway minimum initiation temperature at 60–70°C (per MGN 681 (M) section 6.3). In confined vessel spaces, the heat ignites adjacent materials, gases spread through ventilation systems, and pressure can rupture compartments. ZARGES containment and RACLAN extinguishing systems mitigate these risks by trapping heat, filtering gases, and automatically suppressing flames.
Are ZARGES cases approved for air and sea transport?
Yes. ZARGES BatterySafe cases are UN-certified for hazardous materials transport under IATA (air), IMDG (maritime), and DOT (road) regulations. This certification allows them to be used in container shipments, air freight, and vessel carriage. Always declare battery contents to your freight forwarder and provide the UN certification number for compliance documentation.
Can RACLAN boxes charge batteries while containing a potential fire?
Yes. RACLAN systems are designed to monitor and charge actively. If temperature exceeds threshold during a charge cycle, the system automatically activates an alarm and deploys the extinguishing agent to suppress thermal runaway. The charge stops, the fire is contained, and toxic gases are filtered through the exhaust system. However, the box should not be re-used until inspected and refilled by a qualified technician.
What size batteries fit in RACLAN and ZARGES solutions?
The RACLAN Square (540 × 540 × 235 mm internal) provides thermal containment and extinguishing for batteries up to 3.5 kWh. The smaller RACLAN Box II (540 × 340 × 200 mm internal) handles batteries up to 1.754 kWh. ZARGES BatterySafe cases (C-Series) are tested for thermal containment up to 814 Wh; larger F-Series models are available for bigger battery packs. Contact Mercer Yachting with your battery inventory for correct sizing.
Do classification societies require lithium battery safety equipment?
Requirements vary by flag state and class society. Under MCA MGN 681 (M) Amendment 1, UK-flagged yachts must store batteries above 100 Wh in dedicated cabinets built to standards such as EN 14470, EN 16121, or EN 16122. Charging cabinets must provide temperature monitoring, automatic extinguishing, off-gas venting, and automatic charging shutdown. From 1 January 2027, all battery storage and charging containers on UK-registered vessels must be UK Type Approved by a Nominated Body. Other flag states and class societies have their own evolving requirements — contact your class surveyor for vessel-specific obligations. Mercer Yachting can supply equipment aligned with these requirements and provide supporting documentation.
How should damaged lithium batteries be handled aboard?
Any battery showing physical damage, swelling, casing breaches, or corrosion must be isolated immediately. Place it in a ZARGES case and move to an open deck location away from crew spaces and fuel tanks. Do not attempt to charge or use it. Document the damage, photograph if possible, and contact Mercer Yachting or a certified battery recycler for safe disposal. Never dispose of damaged lithium batteries overboard or in regular waste.
What documentation do we need for lithium battery safety compliance?
Maintain copies of: ZARGES UN certification and product datasheets; RACLAN DMT test certificate and operating manual; crew training records; inventory logs with battery specifications; charging and maintenance schedules; incident/alarm logs; insurance declarations; and flag state compliance letters. Provide these to your underwriter, class surveyor, and port authority as required. Update documentation annually and after any thermal events or equipment replacements.
What is a RACLAN box and how does it work?
A RACLAN box is a lithium fire safety box designed for active charging and storage of lithium batteries aboard yachts and commercial vessels. It features electronic monitoring that oversees the entire charging cycle, acoustic alarm activation when temperature exceeds safety thresholds, optical function control, a built-in emergency power supply, and an integrated TRIDENT® extinguishing system that deploys automatically to suppress thermal runaway. The RACLAN box also includes an advanced exhaust system with toxin filter (hydrogen chloride) to prevent hazardous gases from escaping into crew spaces. The enclosure is made from fire-proof and explosion-proof high-tech composite material and is waterproof and stackable. Available as RACLAN Square (up to 3.5 kWh, 11-litre agent tank) and RACLAN Box II (up to 1.754 kWh, 5.5-litre agent tank). Both models are certified by DMT TÜV Nord.
Where can I buy lithium fire safety boxes for my yacht?
Mercer Yachting supplies RACLAN lithium fire safety boxes and ZARGES BatterySafe cases to superyachts and commercial vessels worldwide. Based in Malta, we deliver to any port in the Mediterranean, Caribbean, Arabian Gulf, and beyond. Contact us at ops@merceryachting.com or +356 79797962 for a quote. We handle product specification, freight, customs documentation, and quayside delivery.
What is the difference between a lithium battery storage box and a lithium fire safety box?
A lithium battery storage box (such as the ZARGES BatterySafe) is a passive containment system designed for safe storage and transport of lithium batteries. It contains fire and filters toxic gases if thermal runaway occurs, but does not actively monitor or extinguish. A lithium fire safety box (such as the RACLAN Active Safety Box) is an active system with electronic monitoring, automatic alarm, and integrated fire extinguishing capability. It is designed for use during active charging, where the risk of thermal runaway is highest. Many vessels use both: ZARGES for transport and storage, RACLAN for active charging.
Do cruise ships need lithium battery fire safety equipment?
Cruise ships face unique lithium fire protection challenges: hundreds of guest and crew devices charging simultaneously, plus operational equipment. MGN 681 (M) Amendment 1 applies to yachts, but the underlying safety principles — dedicated storage above 100 Wh, temperature monitoring, automatic suppression, and mechanical ventilation — are relevant across all passenger vessel types. Consult your class society for vessel-specific requirements.
How do I safely store e-foil and seabob batteries on a superyacht?
E-foil batteries (typically 5–10 kWh) and seabob batteries (2–4 kWh) should be stored in dedicated lithium battery safety boxes when not in use, and charged inside RACLAN active safety boxes with fire suppression capability. Store batteries in ventilated, segregated areas away from fuel tanks and crew accommodation. Never charge unattended without active monitoring. Label each battery with chemistry, capacity, and condition. Mercer Yachting can specify the right combination of RACLAN and ZARGES equipment for your toy fleet.