What happens if a battery runs off a power supply?

If the device is running off battery, the output voltage of the battery will be increased by circuitry to run the device at the required level, however the voltage of the batteries themselves decreases as they loose power (and this is how the amount of charge left is calculated) When you have a power supply, it needs to provide the correct voltage.

What happens if a battery is not connected to anything?

If the battery is not connected to anything, the chemical force is pulling on the ions, trying to draw them across the electrolyte to complete the reaction, but this is balanced by the electrostatic force-- the voltage between the electrodes.

What happens if a charger is not connected to the main power source?

However, if the charger remains connected to the main power source and is not connected to any ‘load’ for days on end, the electricity wastage extrapolated over weeks and months and years may be considerable. At the end of the day, however small in magnitude, it’s just wasted power – power that you could use to charge your devices many times over.

What happens if a laptop battery is 100% charged?

As soon as the battery displayed “100% charge”, you yanked out the power cord from the laptop, but forgot to switch off the mains or remove the charger from the wall. What happens then? In such a situation, the charger will still draw a minimal current from the mains and the regulator will maintain a steady supply of 5 V.

Should a battery be connected to AC source of supply?

In simple words, A battery is DC operated device and should not be connected with AC source of supply. Good to know: The battery electrodes are known as Anode and Cathode. In terms of batteries, Anode is always Negative “-” (having more electrons) while Cathode is Positive “+” (having less number of electrons). Cautions:

Why does no current flow in a battery?

In your battery example, there is no return current path so no current will flow. There is obviously a more deep physics reason for why this works but as the question asked for a simple answer I'll skip the math, google Maxwell's Equations and how they are used in the derivation of Kirchhoff's voltage law.