Gibbs free energy of a reaction (
Δ
G ) is the change in free energy of a system that undergoes the chemical reaction. It is the energy associated with the reaction, which is available to do some useful work. If ΔG<0
, then the reaction can be utilized to do some useful work. If
ΔG>0
, then work has to be done on the system or external energy is required to make the reaction happen. ΔG=0 when the reaction is at equilibrium and there is no net change taking place in the system.
The question is too broad. Depends of the battery and depends where do you connect it to.
define first a battery reaction and where it is connected to define if the reaction is endo or exothermic.
If a battery reaction is exothermic when it is connected to a circuit may be endothermic when it is charged (reverse reaction).
some batteries at low temperature tends to work less, that suggest, they may need absorb some energy from the surroundings.
