Lithium-ion batteries have become highly popular due to their large storage capacity as an energy source. In more recent times, their capabilities have made them ideal for use with fully electric and hybrid petrol/electric vehicles. Governments worldwide are putting forward their goals to be more electric vehicle focused while pressuring car manufacturers to adapt to this. For car manufacturers specifically, it’s perhaps a newer experience dealing with these batteries however it’s incredibly important to be able to handle and store them safely because of how unstable they can be.

One company in particular has been developing new car models which make use of power units with Lithium-ion battery packs. Each battery pack can weigh up to 750kg and inside each pack is an array of thousands of individual Lithium-ion cells which is what causes the biggest risk.

The brief

This company approached Empteezy initially for advice on how to mitigate the uniquely dangerous risks, mainly while the batteries were being stored and moved during production. It was felt that two “bunkers” were needed for the various stages in the process. Firstly, a bespoke unit which could safely quarantine the packs upon delivery to the factory and then a different type of bunker in which a faulty or malfunctioning battery pack could be isolated if a potential thermal runaway event was to occur in the factory. It could be taken to the bunker and safely sealed until the event was over and safely disposed of.

Lithium-ion battery packs present a dangerous fire risk when damaged, faulty or overheat. Any of these can cause an event called a “thermal runaway” which can be dangerous to the battery and its surroundings. This is essentially a chemical fire which generates its own hydrogen and oxygen which self-fuels itself & the fire making the extinguishing of said fire even more difficult than normal. Water itself can’t fully extinguish the fire and a specialised fire extinguishing medium is required to do so, without waiting for the fire to end naturally. It is referred to as a runaway because the fire spreads from cell to cell, heating up the next until it combusts and damages the adjacent cells.

The conclusion

Both bunkers shared similar features in that they had to be secure, protect personnel & surroundings, include the technology to detect a “thermal runaway” event, give accurate internal temperature readings, extinguish (or at least control) chemical fires while providing a stream of cool water via a dry riser. On top of this, battery packs are often moved across production lines by AGV’s (Automatic Guided Vehicles). AGV’s are self-driven robotic cards which would require access to the bunkers for pick-up and deposit of the batteries while also being able to retreat before the closure of the doors. Ingenuity was particularly required during the project to consider everything required.

Nick Freeman, Empteezy’s regional sales manager, was significant in the liaison and development of the bunkers from start to finish. Nick had several meetings with the car manufacturer’s engineers from their research & development site to formulate concepts for the bunkers and gain a better understanding of what it was they needed. With advice and expertise from Empteezy’s CAD designer, Gordon Reid, as well as Paul Whitlam of Nobel Fire systems, the final specifications & designs were created to great satisfaction which covered all of the customer’s requirements.

In summary, this specific unit incorporates the following:

• Can store up to 6 x protective “UN” Battery Boxes (Each box could contain PHEV/BEV car battery array which is deemed as “waste”)
• Can be altered for storing other types of potentially volatile items
• Compliant with all current UK regulations covering oil, chemical & flammable storage
• Backed by our unique 20-year structural guarantee
• Fitted with plinths to eliminate contact with the ground and reduce the risk of corrosion
• Fork Slots to manoeuvre the entire Bunker
• Manufactured in our UK factory
• Safari Roof (false roof to help with temperature control)
• Explosion Relief Panel to the roof
• Light Colour Paint (RAL7035) – To minimise the creation of heat generated from sunlight (Heat is a large problem with Lithium-ion Batteries)
• Tall, tempered glass viewing windows on all doors for safe & easy inspection
• Fire Rated construction to 60 minutes
• AGV tracks and a trap and release mechanism for the battery pack cart
• Cam Locked Doors
• Smoke/Fire detection
• Hydrogen Gas detection
• Internal Temperature monitor display
• Audio and Visual Alarm
• Fire Suppression with Stat-X units
• Dry riser pumping in breach and discharge pipe/nozzles

Did you know? One of the most common causes of incidents are caused from inadequate equipment…You’ll never have that issue with Empteezy…We even offer a 20-year structural guarantee!

We know at Empteezy that preventing potential safety incidents in the workplace or even at home, is essential and sometimes required under law. That is why we do the hard work of creating regulation-compliant solutions to allow the safe storage and appropriate handling of hazardous & non-hazardous items, such as lithium-ion batteries, which require adequate storage.

All of Empteezy’s storage units are manufactured in our factory in Livingston, UK. Each unit is highly robust, sturdy and able to withstand harsh conditions indoors and outdoors, giving you piece of mind that our products have you and your employees covered. Units made from steel are engineered to the highest quality for the safe storage of chemicals, oils, paints, general liquids and potentially volatile items that requires safe containment.

Further general guidance of the safe storage of Lithium-ion batteries is available at https://www.hse.gov.uk/pubns/indg139.pdf.

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