With the development of green shipping, power ships, especially pure battery power ships, have gradually become the focus of industry attention. As the core energy device of pure battery powered ships, the performance, safety and inspection standards of batteries are directly related to the operation safety and efficiency of ships. This paper focuses on the key contents of "Inspection Guide for pure battery power ships", analyzes the technology and safety requirements of power ship batteries in detail, and provides reference for relevant design, manufacture and inspection engineers.

I. Basic definition and characteristics of power ship batteries

power ship battery refers to the energy storage device used in pure battery power ship, which undertakes the task of providing electric energy for ship propulsion system and auxiliary system. Compared with power batteries for land use, ship batteries need to adapt to the special working conditions of marine environment, including high humidity, salt spray corrosion, vibration shock, etc.

Pure battery powered ships usually adopt lithium ion battery technology, which is widely recognized for its high energy density, high charge and discharge efficiency and long service life. However, marine batteries have higher requirements for safety and reliability and must conform to the strict specifications of classification societies and relevant maritime departments.

II. Overview of battery requirements in pure battery power ship inspection guide

the inspection guide for pure battery powered ships specifies the technical and safety requirements for the design, manufacture, installation, operation and maintenance of power ship batteries, mainly covering the following aspects:

1. Battery design and selection requirements

• high security design: Marine batteries must have the protection functions of short circuit, overcharge, overdischarge and thermal runaway. The battery system should be equipped with a complete battery management system (BMS) to realize real-time monitoring and fault warning.
• Airworthiness considerations: battery materials and structures should be able to resist corrosion and mechanical vibration in the marine environment, ensuring long-term stable operation.
• Capacity and power matching: the battery capacity should meet the endurance requirements of ship design, and the power output should meet the maximum power requirements of ship propulsion and auxiliary equipment.
• Modular design: modular design is adopted to facilitate maintenance, replacement and fault isolation, improving the reliability and maintainability of the system.

2. Installation and protection requirements

• fixed installation: The battery pack must be firmly installed to prevent displacement and damage caused by sea turbulence.
• Fire and explosion-proof measures: the battery compartment should have good firewall, explosion-proof facilities and ventilation system to avoid fire or explosion caused by battery thermal runaway.
• Environmental protection: the battery compartment should have waterproof, moisture-proof and salt spray-proof design to ensure that the battery components are not affected by the external environment.
• Electrical Safety:The wiring, insulation and grounding of the battery system comply with relevant electrical specifications to prevent leakage and electrical failure.

3. Operation safety and maintenance requirements

• monitoring and alarm: BMS should monitor the battery voltage, current, temperature and status in real time, trigger an alarm in case of abnormality, and take emergency measures in time.
• Regular testing: The battery system needs to conduct regular capacity testing, internal resistance testing and safety performance evaluation to ensure that it is in good condition.
• Maintenance record: record the battery operating parameters and maintenance history in detail to facilitate fault tracing and management decisions.
• Emergency response plan: formulate emergency treatment plan for battery failure, fire and leakage, and equip necessary fire fighting equipment and safety equipment.

4. Performance and test requirements

• capacity Test: check the actual capacity of the battery under the specified conditions to ensure that it meets the design standards.
• Cycle Life Test: Evaluate the capacity retention rate of the battery after several charge-discharge cycles and judge its service life.
• Security test: includes overcharge, overdischarge, short circuit, extrusion, puncture and thermal shock tests to verify the safety margins of the battery.
environmental adaptability test: test the performance stability of the battery under high humidity, high salt, low temperature and vibration conditions.

III, power ship battery key technical requirements

1. Technical requirements of battery management system (BMS)

BMS is the core guarantee for the safe operation of power ship batteries. The guidelines require that BMS have:

• accurate condition monitoring: real-time measurement of cell voltage, current, temperature and SOC (state of charge).
• Balance function: Ensure the voltage balance of each single battery and prolong the overall battery life.
• Fault diagnosis and protection: can identify overcharge, overdischarge, overtemperature, short circuit and other abnormalities, and automatically take protective measures such as disconnecting the circuit.
• Data recording and communication: records historical data and supports communication with the ship's main control system to facilitate remote monitoring and data analysis.

2. Thermal management system requirements

marine batteries must be equipped with efficient thermal management system to prevent the battery from getting out of control due to high temperature. The thermal management system shall:

• with uniform temperature control capability to avoid local overheating.
• Adapt to the marine environment, using air cooling, water cooling or phase change material cooling technology.
• Ensure system redundancy design, the battery safety temperature can still be maintained when the thermal management system fails.

3. Safety protection design

• mechanical protection: Anti-shock and anti-collision design ensures the complete structure of the battery in the harsh marine environment.
• Electrical insulation: high standard insulation material and design to prevent leakage and electrical failure.
• Fireproof material: adopt flame retardant materials and design to reduce fire risk.

IV. Inspection process and key points

according to the inspection guide for pure battery powered ships, the inspection process of battery systems usually includes the following stages: </span>

1. Design review

review the battery system design scheme and technical parameters, and verify whether the design meets the requirements of guidelines and classification societies.

2. Factory test

test the capacity, internal resistance and safety performance of battery cells and modules to ensure that the product quality meets the standards.

3. Installation Acceptance

check the firmness, protective measures, wiring specifications and environmental adaptability of battery system installation.

4. Running test

the comprehensive performance test of the battery system is carried out on the ship, including charging and discharging performance, thermal management effect and safety protection function.

5. Regular inspection

Carry out maintenance inspection and safety assessment of the battery system according to the specified cycle to ensure long-term reliable operation.

As the core device of pure battery power ship, the design, manufacture, installation and operation maintenance of power ship battery must strictly follow the requirements in the guide for inspection of pure battery power ship. High safety, high reliability and high performance are the basic characteristics of marine power batteries. Through scientific design concept, advanced management system and perfect detection system, the battery system can operate safely and stably in complex marine environment and ensure the normal navigation and operation safety of ships.