All of us are probably used to using our phones while they are charging. This is why manufacturers make longer cables – so that the consumer can have the facility of using and charging the question at the same time.
My question is this: Assuming a cellphone consists of battery with the 'phone' (camera, screen, etc) connected in series, how can we charge it (which would require that current flow in the opposite direction of the battery terminals – we were taught this in physics class – you need to apply a voltage more than that of the cell and in the opposite direction to charge it) and use it (which would require that the current flow in the same direction as battery terminals) at the same time.
My attempt: (two possible cases)
- The above thinking is wrong and somehow the manufacturers managed to use and charge the battery at the same time.
- While charging, the battery does not provide current at all and the current from the wall socket is divided into two currents – one for charging and one for operating the phone.
Which one of the above explanations is correct? Or, is there a third, more complicated explanation?
- If explanation #1 is correct – is this achieved in a simple way or do I need to get a degree in electrical engineering to understand this?
- If explanation #2 is correct – when the phone is being charged and used at the same time, the rate of charging is noticeably slower. Shouldn't the current drawn from wall socket be increased to make it charge at the same rate?