poxkix
Member level 5
I mean that your external power supply will just provide the 5v to the internal charger, the charging is controlled by this internal circuit so even if you connect a 5v/10A source the internal charger will still use a small percentage of this current to load the battery.
Lithium battery charges in constant current and constant voltage stages ( ), the value of the constant current is not controlled by you but from the phone manufacturer and the circuit/code he has implemented internally.
7805 has a typical voltage drop of 2v so you will need 7v input min. in order to get 5v output , if the input is lower then the output will drop.
I would suggest four regulators so that the consumption on the regulators is shared too, you will get up to 2v*1A=2W on each regulator so you will probably be OK even without any heatsink but a small heatsink would weep the regulators cooler.
Wew! I understand. Thanks.
Though a few more questions. Which is doing the control for the charging whenever the battery is full, the cellphone or the charger itself? It baffles me but my bet is the cellphone.
I really forgot on how to determine the time it takes for a specific charger to full charge a cellphone. Do you know how? Like 5v .07A with a cellphone battery of 3.7v 950mA