Assessment electric setup Lithium

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   I have pressed my dealer to get an assessment for the lithium setup and OBMG came back with this (!)
During the inspection of the lithium battery installation on theHanse - H460, several critical safety and compliance issues were identified. These issues not only violate current marine standards in Hong Kong but also pose significant risks to the safety of the vessel, its occupants, and the environment. This report outlines the specific issues discovered, elaborates on their dangers, and provides recommendations for remediation.

Identified Issues
1. Lack of Fusing
• Description: The main battery positive supply cable was found to be without a fuse, utilizing a copper rod instead of an appropriate T-class fuse.
• Danger: In the event of an overcurrent situation, the absence of a fuse can lead to overheating, potential fire hazards, or catastrophic failure of the battery system. Fuses are critical in protecting the electrical system from excessive current.
• Additional Concern: The full current of the battery bank is being carried by a single set of cables (120mm²), which can typically handle around 250A continuously. However, the inverter alone is capable of drawing this current, making it highly likely that the cable is overloaded at times, further emphasizing the need for fusing.
2. 2. BMS and Safety Relay Control
• Description: According to Hong Kong standards, the BMS must send stop charge signals to all charging sources to cease charging. If the charging does not stop, the BMS must alert the operator with a visual and/or audible alarm at the helm. If the operator does not intervene, the BMS should isolate the sources causing overcharging.
• Danger: The current configuration does not meet Hong Kong marine regulations. The battery cut-off is controlled by a Mastervolt shunt, which only monitors voltage, current and battery temperature without communicating with the BMS. Additionally, no visual or audible alarm was found, and the stop-charge function is solely based on Mastershunt parameters, rather than BMS control.
3. Parallel Battery Configuration Exceeding Manufacturer Limits
• Description: The installation included six batteries in parallel, exceeding the manufacturer LIFOS's recommendation of a maximum of four.
• Danger: Overloading the parallel configuration can lead to imbalances in charge and discharge cycles, increasing the risk of battery failure or thermal runaway, which can cause fires or explosions.
4. Unequal Cable Lengths
• Description: The positive and negative supply cables were of different lengths.
• Danger: Unequal cable lengths cause voltage drops and imbalanced loads, leading to uneven charging, potential battery damage, and reduced lifespan and safety of the system.
5. Lack of Individual Connections for Parallel Batteries
• Description: Batteries connected in parallel were linked together without individual cables to a bus bar or safety relays.
• Danger: This configuration creates a single point of failure. If one battery fails, it could compromise the entire system, leading to unsafe operating conditions.
• Additional Concern: The entire current of the battery bank is being handled by a single set of cables. Given the inverter’s current draw, there is a high probability that the cable is overloaded, reinforcing the critical need for fusing (see Issue 1).
6. Inadequate Fire Enclosure
• Description: The batteries were not housed in a fire-resistant enclosure capable of withstanding fire for at least 60 minutes.
• Danger: According to new Hong Kong regulations, the battery compartment must have A-60 fire integrity, ensuring the structure can withstand fire for 60 minutes. Without proper fire containment, a battery fire could spread uncontrollably, posing severe risks to the vessel and crew.
• Pending Confirmation: We are currently confirming additional details with the Marine Department regarding this requirement as it is new to Hong Kong standards.
• Additional Concern: The battery bank also lacks fire protection as per the Hong Kong standard, which states:A battery compartment shall be fitted with fire/heat detectors or a detection system where suitable.
7. Exposed Copper Bus Bars
• Description: The installation featured exposed positive and negative copper bus bars without any protective measures.
• Danger: Exposed bus bars are vulnerable to accidental short circuits, which can lead to fires, equipment damage, and safety hazards.
• Additional Concern: The main positive and negative bus bars were extremely close together. If a tool or other item were to short across them, it could result in a complete lithium bank short circuit, which, without proper fusing (Issue 1), would be extremely dangerous.
8. Weak Link Bars
• Description: Twisted copper link bars were used on the Lithium bank's safety battery relay, compromising their structural integrity and current-carrying capacity.
• Danger: Weak connections can lead to increased resistance, overheating, and potential failure of the electrical system. Reliable connections are essential for safe operation.
• Additional Concern: The modified link bars used in this installation are BEP parts. These were originally flat links but have been modified. While they appear functional, any issues arising from these modifications will not be covered under warranty by BEP. Additionally, bending copper links can create weak points where excessive current could flow through localized areas, potentially leading to overheating and failure.

Conclusion & Recommendations
The inspection of the lithium battery installation on the Hanse H460 revealed multiple critical safety and compliance issues that must be addressed. Each identified issue poses significant risks to the vessel, its occupants, and the environment. Key remediation actions should include:
1. Immediate installation of appropriate fuses (T-Class) to meet marine standards and prevent potential fire hazards.
2. Reconfiguring the BMS control system to comply with Hong Kong marine regulations.
3. Reducing the number of parallel-connected batteries to align with manufacturer recommendations.
4. Equalizing cable lengths to ensure balanced electrical performance.
5. Providing individual connections for each battery to a bus bar or safety relay.
6. Ensuring fire containment compliance by meeting A-60 fire integrity standards (pending Marine Department confirmation).
7. Covering exposed bus bars to prevent accidental short circuits.
8. Replacing or reinforcing weak link bars to ensure reliable and safe operation.
Taking these steps will enhance safety, improve reliability, and ensure compliance with Hong Kong marine standards, ultimately safeguarding all onboard.



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