Storing an old smartphone is not dangerous in itself, but owners should keep an eye on the condition of its battery, since lithium-ion batteries continue to age even when a device is turned off and not in use, according to Roman Shamin, a doctor of physical and mathematical sciences and professor at MIREA Russian Technological University in Moscow. He gave the comments to the Russian news outlet Lenta.ru.
Shamin said slow chemical processes continue inside a battery over time, gradually degrading its components. In some faulty or heavily worn batteries, gas can build up and cause the battery to swell, he said, which in turn can deform the phone's casing, lifting the back cover or the screen. He added that high temperatures, physical damage and improper charging are especially harmful to old batteries.
Fire risk from damaged batteries
According to Shamin, damaged batteries can pose a fire hazard. Faults can trigger an internal short circuit and so-called thermal runaway, in which the battery heats up rapidly, potentially releasing gases, catching fire and, in some cases, destroying the cell entirely.
Shamin said the most obvious warning sign is a swollen battery, which can cause the phone's back cover to come loose or the screen to lift. Unusual heat with no clear cause, a sharp chemical smell, smoke, hissing or other unusual signs should also raise concern, he said.
He advised against charging, disassembling or puncturing the battery of such a phone, or trying to force a deformed casing back into shape. Instead, he said, the device should be handed over to specialists or taken to a collection point that accepts electronic waste and batteries.
Preparing a phone for long-term storage
A smartphone that is still working should be prepared properly before being put away for a long period, Shamin said. Lithium-ion batteries should not be kept fully charged for months at a time, he explained, but deep discharging is also harmful to them.
For long-term storage, Shamin recommended leaving the battery at roughly 40 to 60 percent charge, switching the phone off, and keeping it in a dry, cool place away from heaters and direct sunlight. A removable battery can be stored separately from the phone under the same conditions, he said, though taking the battery out does not eliminate the fire risk. He suggested checking the condition of the phone and battery every few months, and said that if the battery has swollen or the casing has become deformed, the phone should no longer be used normally.
Backing up data before it is too late
Shamin warned that electronics can fail, batteries can become deeply discharged, and data can eventually become inaccessible. He said important photos and files should be transferred in advance to a computer, an external drive or a reliable cloud storage service, and that especially valuable data should be kept in at least two independent copies.
Recycling old devices safely
Shamin said an unwanted smartphone should not be thrown out with ordinary household waste. Electronic devices contain materials that should ideally be recycled, he said, and damaged lithium-ion batteries can create an additional fire risk during waste collection and processing.
He recommended taking an old phone to a specialized electronics collection point, a store that accepts old devices, or using a trade-in program. According to Shamin, the key steps are storing the device correctly, periodically checking the battery's condition, and sending damaged or unneeded gadgets for safe recycling in good time.
Psychiatrist Anna Zotova has previously discussed what unhealthy attachment to gadgets can lead to, saying people with this problem risk facing what she described as digital dementia.
