Cell phones run on various kinds of batteries depending on the manufacturer, phone size or shape and features. There are basically four types of cell phone batteries: Lithium Polymer, Lithium Ion, Nickel Metal Hydride and Nickel Cadmium.
Lithium Polymer is the most recent type and applies the latest technology in DC power. This type of battery is light in weight and will not explode even if pierced. The battery elements are enclosed in platic pouches and do not have memory defects. They last about 50 times longer than Nickel Metal Hydride batteries.
Lithium Ion is also memory efficient and longer lasting than Nickel Metal Hydride batteries but they are quite lighter. They tend to be expensive and would only fit new models of phones. Most Lithium-ion batteries apply a fast charge technique to quickly charge up your cell phone up to 80% capacity and then slowly bring it up to full power in about two hours.
Nickel Metal Hydride is also memory efficient and lasts longer than the NIM type about 40 times. This type of battery is good for people who need rapid charging and if used with a car charger can be fully charged under 1 hour. The special formula permits the concentration of energy in a single pack - sometimes about twice the power of Nickel Cadmium. This type is preferred by a lot of mobile phone users because it lasts long and is cheap. Again, they are non-toxic and appeals to environmentalists.
Nickel Cadmium are the oldest type and has a lot of memory defects. Another severe disadvantage is that they will have to be totally discharged before you can charge them again otherwise you may irreversibly damage them. Again this type is highly toxic due to the presence of Nickel Cadmium and is gradually being phased out by cell phone manufacturers.
Batteries typically have 300 to 400 charge cycles in their life span. It is so because anytime you charge your battery, the battery loses away some of its potency and thus become diminished in power.
Cell phone batteries can be pretty expensive items if you consider the fact that a Nokia 3310 battery can cost up to $24.95. Here are a few tips to prolong the life of your battery:
Dont allow materials to get stuck on the terminals as that causes the battery to lose contact with the terminals resulting in improper connection.

Keep the batteries in a cool place and allow them to adjust to room temperature before charging as the sharp rise in temperature upon charging can damage them.
The life of your cell phone depends on the potency of your battery. Knowing how they operate and how to care for them can ensure that your cellular device runs and runs well for years.