|
Removable LI batteries have a built in temperature sensor (a thermistor usually) included in the package. Ever notice how they have more than two terminals? One of the terminals (or two depending on the manufacturer) is for sensing the temperature and possible explosion if charged too fast. When you removed the battery, the phone's internal charging circuit shut down because it could no longer measure the temperature. If you knew what terminals are the sense terminals (different for each manufacturer) and what resistance the thermistor is a room temperature (usually around 10Kohms), you could connect a resistor to the correct terminals on your phone and run it from the wall charger or computer USB port without a battery. It has nothing to do with the charge only being able to come from the battery, or current limiting from the computer USB port.
Devices with non-removable batteries have this thermistor (or other temperature sensing) built into the device itself and usually glued onto or near the battery which is why the non-removable batteries only have two terminals.
|