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Battery overcharing
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PlainName:
Measured with a charging cable with power display.
The battery may not have been completely charged but the phone said it was. Regardless of the actual battery state, if the phone is saying it is done in order for me to remove power, it comes to the same thing.
PlainName:

--- Quote ---so my Google phone knows to just charge it using low current.
--- End quote ---

My Nothing will kind of do that. If the alarm is set then it will use low power, when wireless charging, so it is full just at the time the alarm goes off. Which suggests it is capable of adjusting the charge rate, at least for wireless charging. But this phone also has the warning about not leaving it on charge.


--- Quote ---Likewise, my Macbook will only charge to 80% as I mostly use it docked as well.
--- End quote ---

Which suggests that limiting the charge is beneficial enough that Apple have the gubbins to achieve that. I'm sure they wouldn't do so if it didn't matter!
Andy Chee:
This article might be useful reading:

https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries


--- Quote ---Lithium-ion suffers from stress when exposed to heat, so does keeping a cell at a high charge voltage. A battery dwelling above 30°C (86°F) is considered elevated temperature and for most Li-ion a voltage above 4.10V/cell is deemed as high voltage. Exposing the battery to high temperature and dwelling in a full state-of-charge for an extended time can be more stressful than cycling.

Most Li-ions charge to 4.20V/cell, and every reduction in peak charge voltage of 0.10V/cell is said to double the cycle life. For example, a lithium-ion cell charged to 4.20V/cell typically delivers 300–500 cycles. If charged to only 4.10V/cell, the life can be prolonged to 600–1,000 cycles; 4.0V/cell should deliver 1,200–2,000 and 3.90V/cell should provide 2,400–4,000 cycles.

In terms of longevity, the optimal charge voltage is 3.92V/cell. Battery experts believe that this threshold eliminates all voltage-related stresses; going lower may not gain further benefits but induce other symptoms

--- End quote ---
Siwastaja:

--- Quote from: PlainName on December 26, 2023, 09:05:06 am ---Measured with a charging cable with power display.

--- End quote ---

So some no-name Ebay thing? I would not trust it.


--- Quote from: Andy Chee on December 26, 2023, 09:25:43 am ---This article might be useful reading:

--- End quote ---

Never trust anything from batteryuniversity.com:


--- Quote ---Lithium-ion suffers from stress when exposed to heat, so does keeping a cell at a high charge voltage. A battery dwelling above 30°C (86°F) is considered elevated temperature and for most Li-ion a voltage above 4.10V/cell is deemed as high voltage. Exposing the battery to high temperature and dwelling in a full state-of-charge for an extended time can be more stressful than cycling.

Most Li-ions charge to 4.20V/cell, and every reduction in peak charge voltage of 0.10V/cell is said to double the cycle life. For example, a lithium-ion cell charged to 4.20V/cell typically delivers 300–500 cycles. If charged to only 4.10V/cell, the life can be prolonged to 600–1,000 cycles; 4.0V/cell should deliver 1,200–2,000 and 3.90V/cell should provide 2,400–4,000 cycles.

--- End quote ---

Emphasis mine; this oversimplification has some truth in it, but take it with a grain of salt.
Siwastaja:

--- Quote from: PlainName on December 26, 2023, 09:08:24 am ---But this phone also has the warning about not leaving it on charge.

--- End quote ---

There are multitude of reasons why such warnings would appear on manuals, and none of us knows all of them. Assuming they must be related to li-ion battery characteristics is likely to go wrong. I would place my bets that this clause is added to reduce risk of fire and electric shock when products are repaired with counterfeit batteries, or when manufacturer has quality control issues with their own batteries (happens rarely), or when the user has bought a crappy non-compliant power supply, which is pretty common. Limiting the time the device is plugged in to bare minimum does not remove these risks, but reduces them. Adding arbitrary limitations is always good for manufacturer from liability viewpoint, so it does not hurt them much. People just normally ignore them, so they are not a nuisance to most; no one buys a different brand of phone because manual said to stop charging.
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