Label stuck on outer packaging depicting the danger posed by lithium-ion batteries Label stuck on outer packaging depicting the danger posed by lithium-ion batteries A pilot with an AvSax fire mitigation bag A pilot with an AvSax fire mitigation bag AvSax fire mitigation bags are designed to deal with all these electronic devices powered by lithium-ion batteries ... plus many more AvSax fire mitigation bags are designed to deal with all these electronic devices powered by lithium-ion batteries ... plus many more

How to send lithium-ion batteries through the post with the Royal Mail. There are tough rules to follow and here they are written simply.

Just about every electronic gadget everyone owns these days is powered by lithium-ion batteries … but few people realise how potentially dangerous they can be. 

The batteries are in everything from mobile phones and laptops to toys but if they become faulty they can go into what’s known as thermal runaway. This happens when one cell in a battery overheats it can produce enough heat – up to 900°C (1652°F) – to cause adjacent cells to overheat. This can cause a lithium battery fire to flare repeatedly even to the point of flames shooting out of the side. 

Airline operators are well aware of the dangers of this happening in the confined space of a cabin with a plane cruising at 35,000ft which is why inventions such as AvSax fire containment bags (www.avsax.com) are on board more than 15,000 aircraft operated by 80 airlines worldwide. 

But most people don’t give a second’s thought to them if sending an item through the post.

That danger was made stark when I ordered an Xbox controller for my son and it arrived in a tightly sealed package with this warning (pictured) on the front. 

It made me wonder just how many people – especially those selling on sites such as eBay and Preloved – may be sending items out with potentially dangerous lithium-ion batteries in them. If one caught fire in a sack in a sorting depot the fire devastation it could cause would be horrendous. 

Cheaper lithium-ion batteries may not have gone through the safety checks or quality control – it’s always best to get batteries from recognised suppliers who meet industry standards for their lithium-ion battery production.  

The Royal Mail has strict rules on lithium batteries … and here they are made as simple as possible. In short, pack them tightly so they can’t move around in the parcel, always tell counter staff at the post office what’s in the package and add your name and address on the outside of the packaging as well the person you’re sending it to. 

If the electronic device such as a mobile phone or digital camera has the batteries with them but not inside the device the maximum number of lithium batteries allowed in each parcel is the minimum number required to power the device plus two spares. 

They must be packed in inner packaging that completely encloses the cell or battery and protect them from short circuit. The equipment sent with cells or batteries must be packed in strong rigid packaging and must be secured against movement within the outer packaging and packed to prevent accidental activation. They must be taken to the post office counter and the sender’s name and address must be visible on the parcel. 

If the batteries are inside the electronic device each parcel must contain no more than four cells or two batteries installed in a device and all the other rules apply. Obviously, any batteries that are defective or damaged are banned. 

The Royal Mail rules go further and get complicated … hopefully the information needed is on the battery or its packaging. 

For batteries either inside the device or sent separately in the packaging the Watt-hour rating must not exceed 20Wh per cell or 100Wh per lithium-ion /polymer battery. For lithium metal/alloy batteries the lithium content must not be more than 1g per cell or 2g per battery. The maximum net quantity of cells or batteries is 5kg per parcel. Each cell and battery must be of a type proven to meet the requirements of each test in the UN Manual of Tests and Criteria, Part III, section 38.3. 

So now you know.