"The Power" behind your works!!!

In this article we aim at giving you an overview of powersupplies and batteries so that you can choose the right one in your works. First lets take a look on how the scientific world calls the batteries we see in everyday life and discuss the highlights features as we go along.

Batteries are classified based on 2 main criterion. Size and Kind.

Based on size, they can be as follows.

First, the batteries that you use in wallclocks are AA sized batteries. They are the kind usually preferred for portable applications. For applications that are a little more portable, like sleek digicams etc we use AAA sized batteries (which are a tad smaller than AA sized batteries). Ok. Now stop wondering if there’s AAAA sized batteries. They exist, but are usually packed in array to form larger sized batteries (more appropriately called ‘battery packs’).

AA and AAA sized batteries are shown below in order. Note that these can be used only for low current applications.

Next are the C - size batteries. They are typically used in medium-current or medium drain applications. Toys are a good example.

D – sized batteries shown below are used in high current drain applications, such as in large flashlights and in those cases where small motors are to be driven.

Battery type	Typical capacity in mAh
AA	2400
C	7800
D	12000

The nominal voltage of these batteries vary from 1.2 V to 1.5V.

For those who wonder what’s the “mAh” in the above table mean, it is “milli ampere hour”. A rating of 2400mAh means that the battery when operated at 2400 mA drains completely in One hour. Its an indication of the energy it can deliver.

Another important battery is the 9 – volt PP3 battery. It just has 6 AAAA sized battery within a single case to supply 9V. This is what is usually used in ‘low power’ projects. Common multimeters use these as power source. PP3 actually refers to the type of connection or snap that is on top of the battery .

Next, based on the kind, there are quite a few classifications.

The batteries discussed above are mostly alkaline batteries. These are not rechargeable. Over time, alkaline batteries are prone to leaking potassium hydroxide, a caustic agent that can cause respiratory, eye and skin irritation. This can be avoided by not attempting to recharge alkaline cells, not mixing different battery types in the same device, replacing all of the batteries at the same time, storing in a dry place, and removing batteries for storage of devices.

Once a leak has formed due to corrosive penetration of the outer steel shell, potassium hydroxide forms a feathery crystalline structure that grows and spreads out from the battery over time, following up metal electrodes to circuit boards where it commences oxidation of copper traces and other components, leading to permanent circuitry damage.

The following batteries are available in wide range of voltage outputs.

The batteries used in electric vehicles are nickel-metal hydride batteries.

The large sized rechargeable battery most frequently used by the beginners is the lead acid battery. Lead acid batteries are available in a variety of sizes ranging from the size of a pocket dictionary to the ones used in trucks.

To be more precise, the ones we use are “valve regulated lead-acid” batteries.

The other popular kind is the Lithium-ion batteries. They are one of the most popular types of battery for portable electronics, with one of the best energy-to-weight ratios, no memory effect, and a slow loss of charge when not in use. The controversial BL 5C batteries in basic Nokia Phones are of this kind. As u might recollect, certain kinds of mistreatment may cause conventional Li-ion batteries to explode.

There are also many other kinds of industry standard. But you might not use them as a student. You can refer to them if you interested.

Now what should you consider before choosing a battery. List the size, weight, voltage of operation, energy/power rating etc. Then pick the one that suits your requirements.