As electronics advance in complexity, functionality, and convenience, so too has their batteries and battery life used to power up these wonderful gadgets. Rechargeable batteries have become increasing popular in electronics, particularly in the more expensive and compact gadgets. They are not as common is less expensive products such as toys, flashlights, or calculators, where alkaline batteries are constantly needed to be purchased. Fortunately, there has been a huge advancement in rechargeable alkaline batteries, which is evident in the much larger selection and lower prices of such batteries in the stores. Although, the slight higher price of these batteries over non-rechargeable alkaline batteries lead many consumers to buy what is more inexpensive, despite the fact that they will lose money in the long run, especially if the devices require a lot of batteries and are used frequently. 
There are different types of rechargeable batteries, the aforementioned batteries are called reusable alkaline batteries, or alkaline cell, which use a powered zinc negative electrode, a positive electrode of manganese dioxide, and an electrolyte of potassium hydroxide.  There are different sizes of alkaline batteries to fit a wide range of devices. These types of batteries have an electromotive force of about 1.5 volts.  Like most batteries, alkaline batteries have two terminals, a positive and a negative. The electrons collect on the negative terminal of the battery, a chemical reaction in the battery produce the electrons. 
Lead-acid batteries are another type of extremely popular rechargeable batteries. These, however, are relatively heavy because of the lead-cell construction. These are the large batteries found in a lot of today’s cars and in many construction vehicles. They are a lot more powerful than alkaline batteries and have a max output of about 12V.  The two terminals of the lead acid battery are usually external bumps where they can be recharged from another battery if it is drained and the car does not start. The positive plate of the lead-acid battery is made of lead peroxide, where as the negative plate is a pure sponge lead plate. The electrolyte in the battery that allows the electrons to flow and produce the energy is diluted sulfuric acid. 
The nickel cadmium battery uses a potassium hydroxide electrolyte, a cadmium and iron oxide negative electrode, and a nickel hydroxide and graphite positive electrode. This type of rechargeable battery provides about 1.25V and has the shortest time to be recharged. It is also the lowest overall cost per cycle, which is why it is used in power tools, but not incredibly popular because of its hazard to the environment due to the cadmium. 
Lithium ion batteries are extremely light and long lasting, they last, if taken care of properly, about 10 years. Unfortunately they are more expensive than the other rechargeable batteries which is why they are more common is more upscale electronics, such as computers, laptops, cell phones, and cameras. Lithium ion batteries are also quite popular because they can be recharged using a USB port, which means electronics like cell phones and mp3 players can be conveniently recharged using the 5-V port in the computer or laptop.  The downside of lithium ion batteries is that they are potentially dangerous because the lithium can cause the batteries to heat up and explode. 
Rechargeable batteries are becoming an important part of our lives, whether we realize it or not. Perhaps more importantly, they are environmentally friendly because they prevent the disposal of regular batteries. Hopefully the advancements keep improving so that practically everything that is powered by batteries become rechargeable.
© Jesse Ramirez. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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