Swollen phone battery: how to make it safe and dispose of it in the UK

What to take away

This article is for readers in the UK. The rules below come from UK law and UK guidance, not from the US or EU. Waste collection is run by councils and arrangements vary by area, so the last step is always your own council.

What a swollen battery is

A phone battery is a lithium-ion cell. When the electrolyte inside breaks down it can release gas, and a sealed cell inflates. In a laboratory overcharge study of a lithium-ion pouch cell with a lithium titanate negative electrode, CT imaging showed gas bubbles trapped between the positive and negative electrode layers, linked to electrolyte reduction during overcharge (Devie and others, Journal of The Electrochemical Society, 2016). That study used a test cell, not a phone, so it explains the mechanism rather than the cause in your handset.

Scottish Fire and Rescue Service lists the warning signs: a swollen battery, a lump or a leak, smoke, extreme heat, hissing or cracking sounds, and unusual smells (SFRS). Apple's safety guide says a battery can be damaged if the phone is dropped, burned, punctured, crushed or exposed to liquid, and that if you suspect damage you should discontinue use (Apple).

Editorial suggestion: treat any swelling as urgent even if the phone still seems to work. You cannot tell from outside how much gas is inside or how the cell will behave under heat or pressure.

Make the phone safe first

Follow these steps in order. They draw on guidance from UK fire and rescue services.

Editorial suggestion: think of a swollen cell as something to replace, not to fix, either by a professional fitting a new battery or by buying a new phone. Samsung's UK self-repair page says not to attempt self-repair on a swollen battery and directs owners to an authorised provider (Samsung UK). Apple's guide says an iPhone battery should be repaired only by a trained technician (Apple). Our guide to smartphone repair routes compares the options for having the cell replaced.

What the law says about disposal

The Waste Batteries and Accumulators Regulations 2009, as amended, are the underpinning law. GOV.UK summarises them as making collection and recycling of batteries compulsory and preventing batteries from being incinerated or dumped in landfill (GOV.UK). The regulations apply across the UK, and the Office for Product Safety and Standards enforces the take-back scheme for distributors and retailers.

The regulations define a portable battery as one that is sealed, can be carried by an average person without difficulty, and is not an automotive or industrial battery (regulation 2). A phone battery meets that description. How you recycle it depends on whether it can be removed.

A loose battery

Retailers and distributors that supply 32 kg or more of portable batteries a year must offer free take-back and keep a collection point at every premises they supply from, including online and telephone sellers. They must accept sealed batteries from phones, laptops and similar devices (GOV.UK). Smaller sellers have no obligation but may take them voluntarily. The GOV.UK consumer guidance adds that lithium battery terminals should ideally be taped up first to reduce fire risk (GOV.UK). Editorial suggestion: do not try this on a swollen cell, which should be handled as little as possible.

A battery built into the phone

For a sealed battery, GOV.UK says the item must be treated as an electrical product. You can take waste electrical products to your local household waste recycling centre, where they should be kept apart from other waste. When you buy a new electrical product, the retailer must accept the old one free on a like-for-like basis. Retailers with an electrical sales area over 400 square metres should accept items under 25 cm on the longest side without a purchase (GOV.UK). A phone is normally well under that size.

This is the Waste Electrical and Electronic Equipment (WEEE) route. Our guide to right to repair and WEEE rules for UK households explains it in more detail. In Northern Ireland, nidirect gives the same advice: if the battery cannot be removed, recycle the whole product with electrical waste, and never put batteries in a household bin (nidirect).

The damaged-cell gap

GOV.UK's guidance does not set a separate procedure for a swollen cell. It does say lithium-ion batteries can catch fire in a bin, with a higher risk if they get wet or are damaged. Buckinghamshire Fire and Rescue Service says not to put a swollen, leaking, smoking or hot battery in household waste or normal recycling, and to contact the manufacturer or retailer, or your local authority, for suitable disposal (BFRS). SFRS says most local recycling centres accept lithium-ion batteries alongside other WEEE, and recommends dedicated recycling points or manufacturer services (SFRS).

Find the official source for your area: GOV.UK's council finder leads to your council's waste pages. Editorial suggestion: ask three things before you go:

Do not post it

A swollen phone may seem easy to send to a recycler or a repairer. The Post Office's restricted-items page, which lists the rules for mail sent through its branches, says damaged batteries of any type are not allowed in UK mail, and that cells or batteries that are defective or damaged are forbidden even when sent with a device (Post Office). It also lists used batteries as environmental waste that cannot be posted.

Editorial suggestion: if a repairer or buy-back company asks you to post the phone, tell them it has a swollen battery before you do anything. Editorial suggestion: assume courier companies have similar rules, and ask the carrier or the company for its dangerous-goods route in writing.

Repair, replace or recycle

A swollen battery does not always mean the phone is finished. A repairer can often replace the cell. Editorial suggestion: ask in advance what happens to the removed battery, and get it on the quote. The repair quote problems guide helps you spot unclear charges. Apple's UK battery page says lithium-ion polymer battery service should be done by Apple or an authorised provider (Apple UK). Its safety guide adds that batteries should be recycled or disposed of separately from household waste, following local rules.

If the phone is old, recycling it through a retailer or council may be the simplest answer. Editorial suggestion: tell the staff when you hand it in that the battery is swollen, so they can treat it as damaged, and do not charge the phone to wipe it.

For charging habits that prevent swelling, see the guide to phone charging problems.

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