Imagine it’s Monday morning and just after you’ve woke up, you realize the battery in your alarm clock has died and you are going to be late to work. So, you’ve decided to call your boss but found out that your mobile battery has died too. So, you connect the charger and thankfully able to open your phone and call to inform your boss about the inconvenience.
Batteries, especially rechargeable batteries have taken an important place in our daily life. Rechargeable batteries have been invented in 1859 though, it has gained its popularity and has come to use widely after the rise of portable devices like smartphones, laptops, torch lights and other cordless power tools.
However, many of you may have an interest in the mechanism of the rechargeable batteries or how they store and provide charge to your portable devices. So, in this article today, we will explain how the rechargeable batteries work.
What is a Rechargeable Battery?
Rechargeable batteries (also known as secondary cells) are the type of electrical batteries with one or more electrochemical cells. These batteries work by reversible cell reactions which allow the batteries to recharge or regain the cell potential after the stored charge has been drained. Rechargeable batteries have a lower environmental impact and cost less than disposable batteries.
How Does a Rechargeable Battery Work?
The batteries we use today are mainly in two types – Primary Cells and Secondary Cells. Primary cells or non-rechargeable batteries are disposal batteries, like alkaline batteries. These batteries contain a number of toxic chemicals of heavy metals. Where the Secondary cells are rechargeable, like nickel-metal hydride (NiMH), lithium-ion (LiOn) and nickel-cadmium (NiCd).
However, both the rechargeable and non-rechargeable batteries produce the current through an electrochemical reaction involving an anode, cathode, and electrolyte. The only difference is: in the rechargeable batteries, the reaction is reversible. This means, when a secondary cell gets electrical energy from an outside source, the negative-to-positive electron flow is reversed during the discharge and the cell charge is restored.
The rechargeable batteries are electromechanical cells that can produce a finite amount of energy. However, it has two processes – The Discharge Process and The Recharging Process.
The Discharge Process
Remember from our early example, you couldn’t speak to your boss firstly because your phone was already discharged. During this discharge period, the rechargeable battery works as a galvanic cell, where all the chemical energy is transformed into electrical energy.
The ions in the electrolyte retort with atoms in the anode, which makes the anode charged negatively. On the other hand, the cathode becomes positive after the chemical reactions with electrolytes. So, there are too many electrons on the anode and on the cathode side, there lacks electrons or negatively charged ions. So, the electrons tempt to move directly from anode to the cathode within the cell, however, the electrolyte here acts as a barrier.
So, it needs an external circuit connection between the anode and cathode. As the anode loss electrons after the connection, it undergoes oxidation. Whereas the cathode undergoes reduction as it gains electrons.
However, when the electron starts flowing through the external electrical connection, the chemical reaction starts at the cathode end and the cells there start functioning. The cell will continue discharging until any of the electrodes run out of reagents to function further reactions. For the secondary cells or the rechargeable batteries, this means it’s time for a recharge.
Can you remember our introductory example, where you could finally speak to your boss after charging your phone? Here the oxidation and reduction processes that occurred during the discharge period are now reversed and the electrical energy transformed back.
However, the basic charging depends on a few factors – constant voltage, constant, current, recharge time. There are many electrical factors here but explaining it simply, we can say, you just need to consider the charging time here and use a good quality charger like Zanflare C4 Smart Charge or Panasonic Eneloop Quick Charger.
Here is a quick guide on how long should you charge rechargeable batteries:
There are rechargeable batteries with different sizes. Bigger batteries have more cells and chemicals inside them. So, the more cells and chemicals inside it, the more it can store energy and release it for longer. It’s a simple theory that the more energy you expect to get out of a rechargeable battery, the longer you will need to charge it.
But most people have the habit of put things on to charge “overnight” and this sometimes decreases the life expectancy of that device or the batteries. With the right amount of charge, a battery can work better and last longer.
So, how long you should charge a rechargeable battery?
The answer is: just check the recommendation on the battery body or the package. Most of the companies put the charging recommendation on the battery’s label. Just read what it says and find out the current rating and adjust the charge time accordingly.
However, in general, the nicad (Nickel-cadmium) batteries recommend a slow charge of 60mA for 14-16 hours. And for fast charging, it recommends 390mA charge current for 2 hours.
And for the NiMH (Nickel-metal hydride) battery, you should charge 63mA for 18 hours or 200mA for 7 hours.
Needs of Rechargeable Batteries
We need rechargeable batteries in many aspects of our daily life. From car battery to beauty products, every power tool needs batteries where there is no power source. However, perhaps, travelers need this thing most.
Suppose you are packing your honeymoon luggage or going on abroad for a tour. As a girl, you obviously try to bring all of your necessary beauty products and hair tools, right? In terms of portability, most girls nowadays prefer to use portable hair tools such as cordless hair straightener and other portable hair styling tools. So, you will need a rechargeable battery to power up the tool while you are abroad. This was just an example. Day by day people likes to use portable tools and gadgets and thus the uses or the needs of the rechargeable battery are increasing.
That’s all for today. Hope you understand and clear out all the confusion about the function of rechargeable battery. If you have any further questions, don’t hesitate to let us know and comment below.