Constantly charging phones: swollen batteries

There is a task, for which I have been using different [unneeded] Android phones. The phone is constantly running an application and constantly charging for many months.

And this is very bad for phone batteries. The result of such use:

These are Lenovo A789, Samsung Note, Samsung Note 3 batteries: 

They all swell because of constant charging. But at least they are removable and can be replaced.

Worse is the Huawei Ascend Mate 7, which has a non-removable battery:

The swollen battery caused the screen to separate from the body (reminds me of my old Apple MacBook Pro A1211, whose battery also swells).

The Samsung Note 3 is currently being used for this task, but the battery has been replaced. I have several.

See also related notes:

• Samsung Galaxy Note 3: проверка трех аккумуляторов (2018-08-08)
• Huawei Ascend Mate 7: быстрый взгляд на смартфон (2015-09-05)
• Samsung Galaxy Note 3 (SM-N9005) (2014-09-27)
• Lenovo A789 (2013-05-08)
• Аккумулятор макбука: кердык (2010-04-23)

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