Why would a battery die when it is brand new and there was nothing wrong the it the night before?

A battery does not CREATE electrical energy, it only stores it. The alternator in your vehicle produces electricity which is used or everything from the radio to charging the battery. If the alternator or regulator fail or if there is a bad electrical connection anywhere, the vehicle may not start next time you get in. If the alternator has failed to charge the battery, there may be nothing actually wrong with the battery except that it has no electrical energy left with which to start your vehicle next time. IF that is the case, all the battery needs is to be charged and it will be able to start your car next time. On the other hand, sometimes batteries get old and just like anything else that gets old they can fail. A 12 volt battery, typical of almost every vehicle on the road today, contains 6 individual cells each capable of producing 2 volts. When cells fail the voltage can be reduced, or the battery can fail completely. So if your car doesn't start it may be a failed battery or it may be a failed charging system or a bad connector. It really isn't possible to give a difinitive answer to your question without being able to test a couple components.