What is it about electricity which causes this? Why can’t a device draw full power until the battery is dead?
In: Physics
There are two separate things that may be happening depending on how complex the device is:
1. Simple devices may connect directly to the battery without any voltage regulation. A battery low on charge will decrease in voltage, especially if you try to draw a lot of power (current) from it. This means that any connected motor will run slower or a light will shine dimmer. A typical li-ion battery will be at 4.2V fully charged and at about 3.2V fully discharged. So it’s a pretty big change from full to empty.
2. Complex devices like a phone, laptop or anything with a microcontroller will have a system that deliberately slows it down in order to reduce battery usage and make it last longer.
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