How works a battery and why ?

google "how a battery works" & do some reading

 CAN! They do not have any LIQUIDS and outlast EVEY OTHER TYPE! In an Electric CAR< you can go from NEW YORK to MIAMI on TWO CHARGES that only take ONE MINUTE to accomplish! 

A car battery?

It's an electrochemical device.

It's a chemical reaction, oxidation, that occurs with a load. Charging reverses it, by reduction .  Details are on the webs and others' answers.

  Fuzzy; you are  Dead Wrong. You describe a Capacitor. 

  Lss, your diagram has  Cathode and Anode reversed. + is Anode or "tip" of a "D" cell, cathode (-) is the base. Current  was defined as flowing from  from Anode to Cathode  long  ago , but this is now incorrect.  

   Your Own words: "Reduction is the gain of electrons, and is what occurs at the cathode; we say that the cathode is reduced during the reaction. Oxidation is the loss of electrons, so we say that the anode is oxidized." So, Cathode would be Minus, or , source Of electrons.

  "Cathode Rays" were described over 100 years ago. With discovery of  the nucleus, these were found to be electrons; negatively charged. They path could be Seen; flowing from cathode, -, to anode, +.

Imagine a world without batteries. All those portable devices we’re so dependent on would be so limited! We’d only be able to take our laptops and phones as far as the reach of their cables, making that new running app you just downloaded onto your phone fairly useless.

Luckily, we do have batteries. Back in 150 BC in Mesopotamia, the Parthian culture used a device known as the Baghdad battery, made of copper and iron electrodes with vinegar or citric acid. Archaeologists believe these were not actually batteries but were used primarily for religious ceremonies.

The invention of the battery as we know it is credited to the Italian scientist Alessandro Volta, who put together the first battery to prove a point to another Italian scientist, Luigi Galvani. In 1780, Galvani had shown that the legs of frogs hanging on iron or brass hooks would twitch when touched with a probe of some other type of metal. He believed that this was caused by electricity from within the frogs’ tissues, and called it ‘animal electricity.

Volta, while initially impressed with Galvani’s findings, came to believe that the electric current came from the two different types of metal (the hooks on which the frogs were hanging and the different metal of the probe) and was merely being transmitted through, not from, the frogs’ tissues. He experimented with stacks of layers of silver and zinc interspersed with layers of cloth or paper soaked in saltwater and found that an electric current did in fact flow through a wire applied to both ends of the pile.

Volta also found that by using different metals in the pile, the amount of voltage could be increased. He described his findings in a letter to Joseph Banks, then president of the Royal Society of London, in 1800. It was a pretty big deal (Napoleon was fairly impressed!) and his invention earned him sustained recognition in the honor of the ‘volt’ (a measure of electric potential) being named after him.

The chemistry of a battery

A battery is a device that stores chemical energy and converts it to electricity. This is known as electrochemistry and the system that underpins a battery is called an electrochemical cell. A battery can be made up of one or several (like in Volta's original pile) electrochemical cells. Each electrochemical cell consists of two electrodes separated by an electrolyte.

So where does an electrochemical cell get its electricity from? To answer this question, we need to know what electricity is. Most simply, electricity is a type of energy produced by the flow of electrons. In an electrochemical cell, electrons are produced by a chemical reaction that happens at one electrode (more about electrodes below!) and then they flow over to the other electrode where they are used up. To understand this properly, we need to have a closer look at the cell's components, and how they are put together.

Electrodes

To produce a flow of electrons, you need to have somewhere for the electrons to flow from, and somewhere for the electrons to flow to. These are the cell’s electrodes. The electrons flow from one electrode called the anode (or negative electrode) to another electrode called the cathode (the positive electrode). These are generally different types of metals or other chemical compounds.

In Volta’s pile, the anode was the zinc, from which electrons flowed through the wire (when connected) to the silver, which was the battery’s cathode. He stacked lots of these cells together to make the total pile and crank up the voltage.

There are a couple of chemical reactions going on that we need to understand. At the anode, the electrode reacts with the electrolyte in a reaction that produces electrons. These electrons accumulate at the anode. Meanwhile, at the cathode, another chemical reaction occurs simultaneously that enables that electrode to accept electrons.

The technical chemical term for a reaction that involves the exchange of electrons is a reduction-oxidation reaction, more commonly called a redox reaction. The entire reaction can be split into two half-reactions, and in the case of an electrochemical cell, one half-reaction occurs at the anode, the other at the cathode. Reduction is the gain of electrons, and is what occurs at the cathode; we say that the cathode is reduced during the reaction. Oxidation is the loss of electrons, so we say that the anode is oxidized.

I can see my battery from my house.

https://simple.wikipedia.org/wiki/Battery

The potential of electrons in the negatively charged plates want to travel to the positive plates where there is an absence of electrons but they can't get there due to separation within the battery, thus when you connect a load you are giving them a path to follow

It's a flipping chemical reaction.

Battery works just fine, because.