[Physics Class Notes] on Batteries in Series vs Parallel Pdf for Exam

Series and Parallel connections are used in two ways in which more than two circuit components are connected : series and parallel , in the series configuration circuits 

Here we have three rosters named as R1, R2, R3 which are connected in the long chain from one terminal of the battery to another terminal. It is noted that the script labeling, those from the little numbers to the lower right letter R, these are unrelated to the resistor values in ohms. They only identify one resistor from one another. The characteristics of a series circuit is that there is only one path for current flow. The current flows in clockwise direction from point 1 to point 2 to point 3 to point 4 and then again back to point 1.

Parallel Circuits Configuration

In the above figure, again we have three resistors, but these form more than one continuous path for current flow. The path is from 1 to 2 then to 7 to 8 and back to 1 again. Another one is from 1-2 to 3-6 to 7-8 and again back to 1. And the third path is from 1-2 to 3-4 to 5-6 to 7-8 then again to 1 back. Each parth that is R1, R2, R3 is called a branch. 

Battery in Series

When we connect batteries in series the voltage is increased. When we connect in series, then we add voltage of batteries together but ampere per hour is different.

If we connect a 6 volt battery, 5 ampere hour (A) and a 12 volt 5Ah battery in series will give a supply of 18 volts that is 6 volts+12 volts, and 5 Ah. 

Often a three 2 volt cell is 6 volt battery and a six 2 volt cell is 12 volts battery. All we have done is connected a nine 2 volt cell together to get an 18 volt battery.

 Battery in Parallel

The battery with lower voltage is charged by the higher voltage just to create balance in the circuits, these are divided into two:

Primary or disposable batteries: these batteries are not designed to take a charge and so the battery with lower voltage is likely to heat up easily it may heat or bulge and in extreme conditions it may even explode. 

Secondary or rechargeable batteries: these are little bit better than the lower voltage batteries, primary batteries are not chargeable after a certain point. But the higher volt batteries are rechargeable and will try it anyway. Higher voltage batteries are drained rapidly. 

How does a Battery Charge Work?

Batteries are very brilliant as it’s power to go. But they have a problem, they can only store a fixed amount of electric charge before running out of life. If we are using rechargeable batteries that can work and create lesser problems, we click them in charged mode and then plug in, after a few time they are again new. A rechargeable battery can be charged hundreds of times. So it can last three or four years or even decades, depending on our usage. It saves our money from buying non rechargeable batteries. Now, understanding batteries and how they work: scientists refer to it as electrochemistry, they release stored electricity, they use the power of chemistry.

In a flashlight if we click the switch on button, we give a green signal to the chemical reaction . As the current flows, the cells which are inside the battery start to transform themselves. The chemicals inside cell stars rearranging themselves. There are two electrical terminals( also known as electrodes) where the chemical reaction takes place 

The chemical inside it is known as electrolyte. The chemical reaction going inside pumps around the circuit around which a battery is connected, which provides a power to the flash.

Cell Type

There are many electrochemical cells produced, with varying designs and chemical processes, including galvanic cells, fuels cells, flow cells, electrolyte cells and voltaic piles. 

Wet cell: It has liquid electrolyte. They are also known as flooded cells. These are known as flooded because of the liquid covering the internal parts, they are also called vented cells as the gas produced during reaction escapes to the air. Wet cells are usually used as learning cells in electrochemistry because they can be built with the common laboratory supplies. Concentration cell is a particular type of wet cell, it is important in understanding corrosion. Wet cells can be both primary cells as well as secondary cells. 

Dry cell: It uses a paste electrolyte with only very less moisture to be allowed for the current to flow. A dry cell can work in any orientation unlike the wet cells. If we do the comparison then the first wet cells were fragile glass containers with lead hanging from the open tops. Whereas a dry cell has a zinc carbon battery and it has a normal voltage of 1.5 volts. 

Molten salt : These are secondary or primary batteries which use molten salts as electrolytes.