this doesn't make sense

[beegoi501]

how come when a mobile device runs out of battery when you try to turn it on it can display that its out of battery when its out of battery?

[Darkseth]

0% on your Battery Bar is not "Battery is 100% empty".

A Battery would be broken/defective, if it would be actually literaly  Empty.

 

Just like 100% on your screen is not actually "full".

 

They make this, so 0% to 100% are within a healthy range on the battery, that doesn't stress it out too much, which would cause it to lose capacity too fast.

 

 

Just check out how much Voltage your battery has at 100%, and how much at 1%.

[fordy_rounds]

It's due to how the manufacturers define "out of battery." Lithium Ion cells have a specific voltage that they cannot go below (if they do, they won't recharge again). As a result, phones are designed to display "out of battery" when well above this voltage. (Battery "percentage" is actually defined by voltages—as a battery's energy is consumed, the voltage declines.) However, there's still a little wiggle room, so they allow a very brief power-on to show "out of battery"—but if it were to do a full power-on, it would use too much power and probably drop you below the absolute minimum.

Note that if you do the partial power-on enough times, it'll stop doing it—it still hasn't dropped below minimum, but it's hit the bottom of the buffer and so it won't let it do anything. (The circuitry is carefully designed so that it will never, in normal use, drop below the absolute minimum.)