Warning: Smartphone battery bulge fire risks

Smartphone battery bulge in older unused smartphones is a fire risk. Yes, it is true, and you could have an unstable fire starter in your old electronics drawer.

First, let’s not pick on one brand as many reports are. Apple and Samsung, by virtue of their market position, have millions upon millions of phones out there. I repeat – it is just as likely to happen with any old phone – there are just a damned side more Apples and Samsungs in the wild.

Back in September, YouTuber Mrwhosetheboss (Arun Maini) noted that two of his collection of old phones – a 2015 Samsung Galaxy S6, and a 2019 Galaxy S10 had swollen batteries that had forced the back panel up. The video is compelling viewing.

On hearing this, I went to my collection, and there was a 2019 Samsung Galaxy S10+ that had forced the back panel off. I rang a mate with an S10 5G, and he had smartphone battery bulge too.

As a bit of a Samsung fan, I review all their phones. After they are superseded, I give them to charities or needy friends. I tracked down users whom I had given a 2020 Galaxy S20 FE, Note 9, S9, and S8, and they had battery issues if the phone had been left unused for some time.

The only other time this has happened to me is with a 2015 iPhone 6, 2017 Moto Z, 2017 Huawei Mate 10 Pro and 2019 Huawei P30 Pro.

What causes smartphone battery bulge?

The electrolyte deteriorates, creating carbon dioxide gas that causes battery bulge. It appears to be more prevalent if the battery is fully discharged (which happens over time).

What to do and not do

First, if you have any old phones lying around, check them for signs of battery bulge.

Second, if you are currently using a phone in a case, take the case off and check for signs.

Do not

  • Ignore it – it is a ticking time bomb.
  • Attempt to remove the back or battery.
  • Attempt to charge it.
  • Throw the phone in the garbage bin – it could cause a fire in the bin or at the waste disposal plant.
  • Transport it in the car without precautions.
  • Use Mobile Muster, Officeworks, Bunnings, Australia Post, or other drop-off recycling services.


  • If you can get a fireproof disposal safe bag, use it to contain the risk. If you cannot, you can wrap the phone in several layers of Aluminium foil.
  • If you want to keep the phone, take it to a mobile-phone repairer to remove and replace the battery. They can dispose of the battery.
  • If the phone is <3 years old, report the matter to the manufacturer. Supply the model and serial number, and they may wish to arrange collection for analysis.
  • Contact your local City Council or use Planet Ark to find a battery recycler. NSW has 90 community recycling centres that can handle damaged batteries.