For instance, if you leave your phone charging all night (say 8 hours)… it stays at 100% for hours while continuing to be plugged up and charging. Where does this extra electricity go if the battery is already full?
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Any modern rechargable battery has a charge controller either built into the battery or into the battery charger that detects when the voltage of the battery reaches optimal level (and therefore is full) and stops the flow of power to prevent overcharging.
In a system without a charge controller (like really old battery powered electronics) overcharging results in the battery being damaged in one way or another, usually wearing them out dramatically faster as the chemistry in the battery is irreversibly changed by the excess energy.
The phone’s battery circuitry is fully capable of independently balancing battery load with incoming available power, and disconnecting or reconnecting as needed. Older batteries may have had problems with this, but modern phones, not so much. We’ve gotten very good at battery state management even while battery lifespans (duration and cycles) are flattening out.
Any modern rechargable battery has a charge controller either built into the battery or into the battery charger that detects when the voltage of the battery reaches optimal level (and therefore is full) and stops the flow of power to prevent overcharging.
In a system without a charge controller (like really old battery powered electronics) overcharging results in the battery being damaged in one way or another, usually wearing them out dramatically faster as the chemistry in the battery is irreversibly changed by the excess energy.
~~It changes to trickle charge.~~ The phone decides to only accept as much electricity as it needs. Newer phones will stop charging at 80 percent and start to charge the rest slowly until you get up.
~~It changes to trickle charge.~~ The phone decides to only accept as much electricity as it needs. Newer phones will stop charging at 80 percent and start to charge the rest slowly until you get up.
The phone’s battery circuitry is fully capable of independently balancing battery load with incoming available power, and disconnecting or reconnecting as needed. Older batteries may have had problems with this, but modern phones, not so much. We’ve gotten very good at battery state management even while battery lifespans (duration and cycles) are flattening out.
Nowhere.
The phone charge is really just a power supply in almost all phones. It has a constant voltage and can provide a max current. It is the phone that determines the current that is drawn. So when the battery is full only enough current to power the phone is drawn.
Compare to a wall outlet where the current is determined by what you connect, A 20W and 100W incandescent light connected to tow outlets will have a current that differs by a factor of 5 but the voltage is the sam for both.
You can have electronics that control, for example, the brightness of a lamp, and the current from the outlet will depend on the lamp’s brightness.
Tecnialy Li-ion charging is done with a constant voltage when the battery is above ~80% full and the current depends on the voltage difference between the battery and the charge circuit. That does require voltage conversion from the USB input voltage and practically is the same as the phone controlling the current to it.
The telephone regulates the current it draws to trickle charge the battery and compensate the power drawn from keeping the device running. It measurs how full the battery is by its voltage and gradually decreases the charging current. You might feel the power supply unit getting warm at the beginning of the charging session, and then cool down because it doesn’t have to do as much work.
The telephone regulates the current it draws to trickle charge the battery and compensate the power drawn from keeping the device running. It measurs how full the battery is by its voltage and gradually decreases the charging current. You might feel the power supply unit getting warm at the beginning of the charging session, and then cool down because it doesn’t have to do as much work.
Nowhere.
The phone charge is really just a power supply in almost all phones. It has a constant voltage and can provide a max current. It is the phone that determines the current that is drawn. So when the battery is full only enough current to power the phone is drawn.
Compare to a wall outlet where the current is determined by what you connect, A 20W and 100W incandescent light connected to tow outlets will have a current that differs by a factor of 5 but the voltage is the sam for both.
You can have electronics that control, for example, the brightness of a lamp, and the current from the outlet will depend on the lamp’s brightness.
Tecnialy Li-ion charging is done with a constant voltage when the battery is above ~80% full and the current depends on the voltage difference between the battery and the charge circuit. That does require voltage conversion from the USB input voltage and practically is the same as the phone controlling the current to it.
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