One of the fundamental laws of physics says that energy can neither be created nor destroyed. It can only be converted. In truth, that principle is the foundation of the building of a battery. We typically think of batteries as energy storage devices. They are, but only to a certain degree. But batteries are more an energy conversion device than anything else.
If you have always assumed that batteries store electricity, flush those thoughts from your mind. It is not true. Any storage potential that batteries do possess is in the form of chemical energy. That chemical energy is created through a transfer of electrical energy to the chemical components inside of the battery.
If this all sounds complicated, stop and take a deep breath. It’s actually simpler than you might think. A good way to understand the battery concept is to frame it using something else you already understand. One example that immediately comes to mind is video game consoles.
Consoles Store Potential
You may have a game console connected to your TV. As you know, the console does not store tiny little characters who run around and do strange things. Those characters aren’t real. They are just visual representations of data entered by coders. What your game console stores is potential. It has the potential to turn game data into visual images and audible sounds.
You feed data to the console by way of a DVD or an online platform. The data flows into the console and begins interacting with the circuitry and software inside. That computer takes the data and uses it to create what you see on your screen. Without circuitry and software, there is no potential for transforming game data into what you see and hear.
Batteries Store Potential
If we compared a Pale Blue Earth USB rechargeable battery to a game console, we would liken the internal chemicals to your console’s software and circuitry. Electricity is comparable to the data you feed your console.
In order to charge a lithium-ion battery, you connect it to a power source. The connection forces electricity through the battery – just like data being fed to a game console. Electricity forces ions to move from the positive side of the battery to the negative side. This can be compared to data flowing into your game console’s CPU, where it is processed before generating output.
As long as you do not use a fully charged battery, the ions remain at the negative side. But they could potentially move back to the positive side under the right conditions. Those conditions are present when you insert the battery into a device and turn the device on.
At that point, ions move back through the battery just like data moving from your game console CPU to your TV screen. The movement of the ions generates electricity just as the movement of data creates sounds and images.
Conversion Both Ways
Hopefully you understand the concept being illustrated here. Batteries are more conversion devices than storage devices. Electrical energy is converted to chemical energy when a battery is charged. Chemical energy is converted to electrical energy upon discharge. In between, the only thing being stored is potential.
This explains why a fully charged battery doesn’t weigh more than a discharged battery. Nothing physical or tangible goes into the battery during charging. All charging does is change the state of the chemical components inside. It is that change of state that gives batteries the potential to produce electricity.
Still don’t understand? No worries. What’s most important is that your batteries work when you need them.