BU-409: Charging Lithium-ion
A lithium battery charger will damage a lead acid battery by overcharging it with high voltage. But not the other way around. ... voltage to the phone, but how is that then fed to the battery? Let''s say you have 9V/2A going to the phone from the power supply. Is the battery then being fed a 9V input voltage, or is the phone''s charging circuit ...