Section 7 Batteries

7.1.1 The requirements of this Section apply to aqueous and non-aqueous permanently installed secondary batteries of the vented and valve-regulated sealed type.

• Goal

  Safe energy storage and dependable supply of power to consumers.

• Functional requirements

  Reasonably foreseeable hazards external to the battery shall be identified and managed.

  Reasonably foreseeable hazards internal to the battery shall be identified and managed.

7.1.2 A vented battery is one in which the cells have a cover provided with an opening through which the products of electrolysis and evaporation are allowed to escape freely from the cells to the atmosphere.

7.1.3 A valve-regulated sealed battery is one in which the cells are closed but have an arrangement (valve) which allows the escape of gas if the internal pressure exceeds a predetermined value. The electrolyte cannot normally be replaced.

7.1.5 Lithium battery systems are to be Type Approved in accordance with LR’s Type Approval System Test Specification Number 5 (2019), or alternatively manufactured and tested to assess compliance with the applicable International or National Standards, and application of an acceptable quality management system, may be submitted for consideration.

7.1.6 The battery management systems are to be Type Approved in accordance with LR’s Type Approval System Test Specification Number 1 (2018), or alternatively manufactured and tested to assess compliance with the applicable International or National Standards, and application of an acceptable quality management system, may be submitted for consideration.

7.1.7 Where the lithium battery total system installation is less than 20 kWh then it is to be housed in a gastight steel enclosure with a gastight ventilation duct leading to a safe space on open deck and is to be suitable for withstanding the temperatures and pressures generated in the worst case thermal runaway condition. The battery system is to satisfy the requirements of LR’s Type Approval System Test Specification Number 5 (2019), or an equivalent and acceptable National or International Standard, amended where necessary for a battery space ambient temperature of 45°C. Alternative arrangements are subject to special consideration.

7.1.8 The following Sections apply to lithium battery system installations of a capacity 20 kWh or greater and are in addition to those applicable in other Parts of these Rules:

• Vol 2, Pt 9, Ch 2, 7.1 General requirements 7.1.9;
• Vol 2, Pt 9, Ch 2, 7.2 Design and construction 7.2.2 to Vol 2, Pt 9, Ch 2, 7.2 Design and construction 7.2.6;
• Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.11;
• Vol 2, Pt 9, Ch 2, 7.4 Installation 7.4.5 to Vol 2, Pt 9, Ch 2, 7.4 Installation 7.4.9;
• Vol 2, Pt 9, Ch 2, 7.5 Thermal management and ventilation 7.5.7 and Vol 2, Pt 9, Ch 2, 7.5 Thermal management and ventilation 7.5.11;
• Vol 2, Pt 9, Ch 12, 1.1 Testing 1.1.6.

7.1.9 For lithium battery system installations of nominal voltages exceeding 1500 V d.c., a Risk Assessment is to be carried out in accordance with the requirements of Vol 2, Pt 1, Ch 3, 18 Risk Assessment (RA).

7.1.10 Integration of a lithium battery system that satisfies a ship’s main power demand into the ship’s electrical power system is to be in accordance with Vol 3, Pt 1, Ch 6 Hybrid Electrical Power Systems.

7.2.1 Batteries are to be constructed so as to prevent spilling of the electrolyte due to motion and to minimise the emission of electrolyte spray.

7.2.2 A Failure Mode and Effects Analysis (FMEA) is to be carried out for the lithium battery system installation and is to consider the effects of failure upon safety and dependability of the lithium battery system installation, taking account of reasonably foreseeable internal and external failures such that the goal and functional requirements of Vol 2, Pt 9, Ch 2, 7.1 General requirements 7.1.1 are achieved and is to include but is not limited to the following:

1. overpressure, fire and explosion;
2. electrical short circuit due to leakage of cell electrolyte or mechanical impact;
3. venting out flammable and toxic gases;
4. rupture of the casing of cell, battery module, battery pack or battery system with exposure of internal components; and
5. ingress of water into the battery space from cooling system leak, fire suppression system release and/or adjacent areas.

7.2.3 The casing of a lithium cell and/or battery module is to incorporate pressure relief functions that will prevent overpressure, rupture or explosion of the battery module enclosure (see Vol 2, Pt 9, Ch 12, 1 Testing and trials).

7.2.4 The lithium battery management system is to continuously monitor the condition of cells, battery modules or battery packs and to maintain them within their specified safe operating region. As a minimum the alarms and safeguards as indicated in Table 2.7.1 Lithium battery system: alarms and safeguards are to be provided:

7.2.5 A fully independent hard-wired means to disconnect the battery system in an emergency from power distribution is to be provided. This emergency trip is to be located outside of the battery space and situated such that it will remain accessible in the event of an emergency inside the battery space and is to initiate an audible and visual alarm at the relevant control stations to advise duty personnel of the emergency condition.

7.2.6 For lithium battery system installations the following is to be measured and displayed at relevant manned control stations:

1. State of charge (SOC) and state of health (SOH) are to be displayed at relevant control stations and on the navigating bridge.
2. System alarms are to be displayed at relevant control stations and at least a common alarm displayed on the navigating bridge.

7.3.1 Vented batteries connected to a charging device with a power output of more than 2 kW, calculated from the maximum obtainable charging current and the nominal voltage of the battery, are to be housed in an adequately ventilated compartment assigned to batteries only, or in an adequately ventilated suitable box on open deck.

7.3.2 Vented batteries connected to a charging device with a power output within the range 0,2 kW to 2 kW, calculated from the maximum obtainable charging current and the nominal voltage of the battery, are to be installed in accordance with Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.1, or may be installed in a box within a well ventilated machinery or similar space.

7.3.3 Vented batteries connected to a charging device with a power output of less than 0,2 kW, calculated from the maximum obtainable charging current and the nominal voltage of the battery, may be installed in an open position or in a battery box in any suitable space.

7.3.4 Where more than one charging device is installed for any battery or group of batteries in one location, the total power output is to be used to determine the installation requirements of Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.1, Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.2 or Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.3.

7.3.5 Valve-regulated sealed batteries may be located in compartments with standard marine or industrial electrical equipment provided that the ventilation requirements of Vol 2, Pt 9, Ch 2, 7.5 Thermal management and ventilation 7.5.10and the charging requirements of Vol 2, Pt 9, Ch 2, 7.6 Charging facilities 7.6.4 and Vol 2, Pt 9, Ch 2, 7.6 Charging facilities 7.6.5 are complied with. Equipment that may produce arcs, sparks or high temperatures in normal operation is not to be in close proximity to battery vent plugs or pressure relief valve outlets.

7.3.6 Where lead-acid and nickel-cadmium batteries are installed in the same compartment, precautions are to be taken, such as the provision of screens, to prevent possible contamination of electrolytes.

7.3.7 Where batteries may be exposed to the risk of mechanical damage or falling objects, they are to be suitably protected.

7.3.8 A permanent notice prohibiting naked lights and smoking is to be prominently displayed in all compartments containing vented type batteries.

7.3.9 Only electrical equipment necessary for operational reasons and for the provision of lighting is to be installed in compartments provided in compliance with Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.1, the compartment ventilation exhaust ducts and zones within a 1,5 m radius of the ventilation outlet(s). Such electrical equipment is to be certified for group IIC gases and temperature Class T1 in accordance with the applicable parts of IEC 60079: Explosive atmospheres,, or an acceptable and relevant National Standard.

7.3.10 A permanent notice is to be prominently displayed adjacent to battery installations advising personnel that replacement batteries are to be of an equivalent performance type. For valve-regulated sealed batteries, the notice is to advise of the requirement for replacement batteries to be suitable with respect to products of electrolysis and evaporation being allowed to escape from cells to the atmosphere, see also Vol 2, Pt 9, Ch 1, 1.7 Alterations and additions 1.7.6.

7.3.11 The lithium battery space is not to be located forward of the collision bulkhead and is not to be contiguous to the boundaries of machinery spaces of Category A or those spaces containing the main source of electrical power, associated transforming equipment (if any) or the main switchboard. The boundaries of the lithium battery space are to be part of a vessel structure or enclosures and provided with ‘A-60’ insulation of the bulkhead unless the space is adjacent to spaces of negligible fire risk such as cofferdams, void spaces, or similar in which case consideration can be made to reduce the insulation to ‘A-0’. Penetrations through these boundaries are to be protected to the same fire protection standard. Special consideration will be made for a ship not built of steel or equivalent material. All other safety systems within the lithium battery spaces are to be in accordance with the requirements of this Part or, if not made explicit, at least equivalent to those of a machinery space of Category A.

7.3.12  Approaches to protect equipment within critical compartments from representative fragmentation and small arms threats are described in optional notations, see Vol 1, Pt 4, Ch 2, 4 Fragmentation protection

7.4.1 Batteries are to be arranged such that each cell or crate of cells is accessible from the top and at least one side and it is to be ensured that they are safely secured.

7.4.2 The materials used in the construction of a battery rack or stand are to be resistant to the battery electrolyte or suitably protected by paint or a coating.

7.4.3 Measures are to be taken to minimise the effect of any electrolyte spillage and leakage, for example the use of rubber capping around the top of the cells and the provision of a tray of electrolyte-resistant material below the cells, unless the deck is suitably protected with paint or a coating.

7.4.4 The interiors of all compartments for batteries, including crates, trays, boxes, shelves and other structural parts therein, are to be of an electrolyte-resistant material or suitably protected, for example with paint or a coating.

7.4.5 Battery systems are to be installed in accordance with manufacturer’s recommendations taking account of the results of the risk assessment or FMEA, where applicable.

7.4.6 The lithium battery space and the crates, trays, boxes, shelves and other structural parts therein are to be designed and constructed such that the structural integrity of the battery space will not be compromised in the event of a lithium fire.

7.4.7 The lithium battery space is to be fitted with suitable fixed detectors in accordance with manufacturer’s recommendations and which are capable of providing early identification of a fire or thermal runaway condition. Early identification is to include high cell temperature or detection of electrolyte solvent vapours and a combination of smoke and heat detectors. When activated, the fire detection system is to initiate an alarm to the relevant control stations and on the navigating bridge and is to initiate the automatic isolation of electric systems within the lithium battery space, except as described below, and activate the fixed fire-fighting system.

7.4.8 In the event that a fire or thermal runaway condition is identified, the battery monitoring system is to initiate protective features such as automatic safe isolation of the batteries. Ventilation necessary for extraction of gasses, active cooling systems, and thermal/safety monitoring and alarm are to be continued prior to, during and after an overheating or fire event. Failure of the monitoring system is to be alarmed to the ship’s safety system and is to result in the battery system automatically reverting to a defined safe state.

7.4.9 An appropriate water-based fixed fire-fighting system in accordance with SOLAS II-2, Part C, Regulation 10.4.1.1.3 and the manufacturer’s recommendation is to be provided for the lithium battery space. The fixed fire-fighting system is to be suitable for heat removal, boundary cooling and/or extinguishing for the duration that the heat and/or gas release are present. Fixed fire-fighting systems using a medium other than water which provide equivalent heat removal, boundary cooling and/or extinguishing for the duration that the heat and/or gas release is present can be taken into consideration provided that appropriate fire tests have been conducted. In particular, the fire-extinguishing media are to be chosen as appropriate for the specific type and characteristics of fire foreseen.

7.4.10 The fixed fire-fighting control system is to be located outside the battery space, be activated automatically and be capable of manual activation. In addition to the fixed fire-fighting system, the battery space is to be provided with a minimum of two (2) portable and suitable fire-extinguishers located outside the space at or near the entrance(s) and in agreement with the Naval administration/authority. The number and position of hydrants are to be such that at least two jets of water not emanating from the same hydrant, each from a single length of hose, can reach any part of the lithium battery space. Such hydrants are to be positioned in close proximity to the lithium battery space. Any part of the fire-fighting system which crosses through the lithium battery space without serving it is to be avoided.

7.4.11 The fire detection and automatic water-based fire-fighting systems are to be in accordance with the recommendations of the battery manufacturer and the following sub-Sections of these Rules:

• Vol 2, Pt 9, Ch 9, 4.1 General;
• Vol 2, Pt 9, Ch 9, 5.1 Automatic sprinkler system;
• Vol 2, Pt 9, Ch 9, 5.2 Fixed water-based local application fire-fighting systems;

7.4.12 The technical description detailed in Vol 2, Pt 9, Ch 1, 1.4 Documentation required for design review 1.4.27 is to consider the actual battery system installation and its integration into the ship, including but not limited to the following:

• arrangement of battery compartment (location, including fire risk of adjacent spaces/compartments, fire burden from equipment other than batteries, heat sources, etc.);
• temperature control arrangements for the battery space and their contribution to system safety;
• ventilation arrangements to prevent concentrations of gasses within the space in case of uncontrolled thermal runaway;
• hazardous area(s) requirements;
• reasonable gas tightness of ventilation ducting;
• fire integrity of the space;
• the use of fire extinguishing arrangements for cooling in the case of uncontrolled thermal runaway.

The FMEA referenced in Vol 2, Pt 9, Ch 2, 7.2 Design and construction 7.2.2 should address any additional failure modes identified during the preparation of this technical description.

7.4.13 The lithium battery space is to be provided with two means of escape, at least one independent of any watertight door and leading to a safe position outside the space. One of the escapes is to be suitable for the passage of a stretcher. At each entrance/exit an emergency escape breathing device (EEBD) is to be provided. Where the maximum travel distance to the door within the lithium battery space is less than 5 m, a single means of escape is acceptable. The lithium battery space is not to be considered as part of an escape route (primary or secondary) from any other accommodation, control, service space, machinery space of Category ‘A’ and high fire risk area such as a garage, paint store, etc.

7.5.1 Battery compartments and boxes are to be ventilated to avoid accumulation of dangerous concentrations of flammable gas.

7.5.2 Ducted natural ventilation may be employed for battery installations connected to a charging device with a power output of 2 kW or less, provided the exhaust duct can be run directly from the top of the compartment or box to the open air above, with no part of the duct more than 45º from the vertical. A suitable opening is also to be provided below the level of the top of the batteries, so as to ensure a free ventilation air flow. The ventilation duct is to have an area not less than 50 cm² for every 1 m³ of battery compartment or box volume.

7.5.3 Where natural ventilation is impracticable or insufficient, mechanical ventilation is to be provided, with the air inlet located near the floor and the exhaust at the top of the compartment.

7.5.4 Mechanical exhaust ventilation complying with Vol 2, Pt 9, Ch 2, 7.5 Thermal management and ventilation 7.5.9 is to be provided for battery installations connected to a charging device with a total maximum power output of more than 2 kW. Also, to minimise the possibility of oxygen enrichment, compartments and spaces containing batteries with boost charging facilities are to be provided with mechanical exhaust ventilation irrespective of the charging device power output.

7.5.5 The ventilation system for battery compartments and boxes, other than boxes located on open deck or in spaces to which Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.2, Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.3 and Vol 2, Pt 9, Ch 2, 7.3 Location 7.3.5 refer, is to be separate from other ventilation systems. The exhaust ducting is to be led to a location in the open air, where any gases can be safely diluted, away from possible sources of ignition and openings into spaces where gases may accumulate.

7.5.6 Fan motors associated with exhaust ducts from battery compartments are to be placed external to the ducts and the compartments.

7.5.7 Ventilating fans for battery compartments are to be so constructed and be of material such as to minimise risk of sparking in the event of the impeller touching the casing, and are to be suitable for the potentially hazardous and corrosive gases produced in a thermal runaway condition. Non-metallic impellers are to be of an anti-static material.

7.5.8 Battery boxes are to be provided with sufficient ventilation openings located so as to avoid accumulation of flammable gas whilst preventing the entrance of rain or spray.

7.5.9 The ventilation arrangements for all installations of vented type batteries are to be such that the quantity of air expelled is at least equal to:

Q

=

110 n

where

7.5.10 The ventilation rate for compartments containing valve-regulated sealed batteries may be reduced to 25 per cent of that given in Vol 2, Pt 9, Ch 2, 7.5 Thermal management and ventilation 7.5.9

7.5.11 Thermal management of the lithium battery space is to be assessed, including the criticality of any cooling systems required to ensure reliable operation and to prevent thermal runaway within the marine environment. See also Vol 2, Pt 9, Ch 1, 1.5 Documentation required for supporting evidence 1.5.4.

7.6.1 Charging facilities are to be provided for all secondary batteries such that they may be completely charged from the completely discharged state in a reasonable time having regard to the service requirements.

7.6.2 Suitable means, including an ammeter and a voltmeter, are to be provided for controlling and monitoring charging of batteries, and to protect them against discharge into the charging circuits.

7.6.3 For floating circuits or any other conditions where the load is connected to the battery whilst it is on charge, the maximum battery voltage is not to exceed the safe value for any connected apparatus.

7.6.4 Arrangements are to be fitted to automatically control the charging rate of valve regulated sealed batteries so as to prevent overcharging which may lead to an excessive evolution of gas. These arrangements are to take account of any requirements for prolonged operation under close down conditions.

7.6.5 Boost charge facilities, where provided, are to be arranged such that they are automatically disconnected should the battery compartment ventilation system fail.

7.7.1 A schedule of batteries fitted for use for Mobility systems, Ship Type systems, and emergency services is to be compiled and maintained.

7.7.2 Procedures are to be put in place and documented to ensure that, where batteries are replaced, they are of an equivalent performance type, see also Vol 2, Pt 9, Ch 1, 1.7 Alterations and additions 1.7.6.

7.7.3 When additions or alterations are proposed to the existing batteries for Mobility systems, Ship Type systems, and emergency services, the schedule and replacement procedure documentation are to be updated to reflect the proposed installation and submitted in accordance with Vol 2, Pt 9, Ch 1, 1.7 Alterations and additions 1.7.1.

7.7.4 The schedule and replacement procedure documentation are to be made available to the LR Surveyor on request.