I’ve noticed that my phone will charge really quickly up to 50%ish and then the speed it charges to 100% is much slower. I’ve found this true for other devices too, why do batteries charge quicker when they’re empty and then the speed slows down to get it to 100%?
In: Technology
This is because of how modern lithium battery charges.
The battery starts with a “constant current charge”. Where the charger gives the battery the amount of electrical current the battery is rated for. And the battery charges at it’s best speed.
However, as the battery fills, the voltage inside the battery goes up. And to avoid damage to the battery the charger now has to switch to “Constant voltage charging”. Here, the charger feeds the battery only with a certain amount of voltage or “pressure” and the battery simply takes as much electrical current as it can handle. And it charges signifficantly slower therefore.
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