What is meant by the phrase 'total battery of tests'?
A "Battery of Tests" is a term that refers to a greater than normal health related testings for a specific problem.
If the 2nd battery is connected "in series" with the 1st battery, the voltage will increase & the motor will run faster. If the 2nd battery is connected "in parallel" with the 1st battery, the voltage will not change, but the total battery capacity will be greater & therefore battery life will be longer than when using just 1 battery.
this phrase refers to the" law of conservation of mass ".this law states that the total mass of the reactants is equal to the total mass of products after reaction has completed .or the total number of atoms taking part in a chemical reaction as reactants is equal to the total number of atoms obtained as products