Pros : Cheapest variety of batteries. Thereby, highly affordable. Bring down the overall cost of the mobile phone.

Cons : Extremely prone to the "Memory Effect". Must be discharged and recharged fully on every recharge cycle.

NiMH (Nickel Metal Hydride) :
A better battery species than the NiCad ones. They are prone to the "Memory Effect" to a very small extent. To maximise performance, it is advised to completely discharge the battery after every 20th recharge.

 

Pros : Cheaper than Li-Ion Batteries. Thereby, more affordable. Bring down the overall cost of the mobile phone.

Cons : Prone to the "Memory Effect" to a small extent. Must be discharged fully on every 20th recharge cycle.

Li-Ion (Lithium-Ion) :
These are considered the most advanced widespread cell phone batteries available. Eventually, they should totally replace NiMH and NiCad batteries. They are not subject to the "Memory Effect" at all. Hence, they may not be completely discharged after any number of recharge cycles.

 

Pros : Lighter and slimmer than the NiMH and NiCad batteries. Usually, offer a longer standby time and talktime. Are not subject to the "Memory Effect".

Cons : Expensive.

Li-Polymer (Lithium Polymer) :
These batteries are still quite rare and an even more advanced type of batteries. That technology helps make even thinner and lighter batteries.


Memory Effect :
We stated that the NiCad and NiMH are subject to the "Memory Effect" to a large and small extent respectively. Let's find out what it actually is...
Suppose you recharge your phone battery everytime when your battery is 60% discharged. Eventually, it will so occur that as soon as the phone gets discharged by 60%, it will "forget" that the battery has the 40% charge remaining. It will hence show the "Battery Low" indication. The rest of the 40% charge is wasted (You cannot recover it). This simply leads to a huge reduction in talk-time and standby time.

Extend Your Standby and Talktime : Reduce Your Consumption

There are a few things you can do that won't necessarily affect your habits, while reducing your energy consumption, thus allowing you more standby and talktime between each charges :

Get rid of the little sound that the phone makes when you press a key. You should find how to do that in your phone's settings.
Use a louder ringtone instead of the vibration alert whenever possible. Ringtones drain lesser energy.
The backlight makes the screen and keys of your phone visible in the dark when you open the flip cover or press a key. As you will notice, that light times out, typically after two or three seconds. On most phones, you can adjust - and reduce - the backlight timeout. Make it as low as possible.
If you have a dual mode "digital and analog" phone, this one is very important... when you travel in an "Analog Area" and you know you won't need your phone for a while, turn it off, since the analog system is tougher on cell phone batteries. Digital phones actually have power management features - similar to those of your computer - that analog phones don't have. For example, a Nokia 6160 has 100 to 200 hours of standby time in digital mode but only 30 to 50 hours when in an analog area. A huge difference!


Three Golden Rules About Batteries

1. Always treat your mobile-phone battery with care. Do not drop or hit it against any hard objects. And try to take extra care of the metal contact plates as they determine the connection between the mobile phone and the battery.

2. Turn OFF the phone before removing the battery. Many phone users neglect this important step, which ultimately reduces the overall performance of the battery.

3. Avoid exposing battery in the sun, as extremely high temperature reduces the capacity of the battery permanently. This commonly occurs in cases where phone owners leave their phones in the cars parked under direct sunlight.

Some Supplementary Notes On Battery Care :

A battery has a long maintenance-free service life if properly treated.
Never let a battery get into contact with metal objects that may short-circuit the battery poles : For example, a bunch of keys (or metal coins) in a pocket.
A battery may explode if disposed of in a fire.
Do not disassemble a battery.
If you suspect a battery of not working properly, take it to an authorized dealer.
If left unused, a fully charged battery will discharge itself in a few months time.
When not being used, batteries should be stored uncharged in a cool, dark and dry place.
Always use original batteries and battery chargers. Although initially expensive, they will prove more beneficial in the long-run.

A Word on Cell Phone Battery Protection

Finally, cell phone batteries don't only have a standby time and talktime... they also have an overall lifetime. Usually, it is stated in charge cycles, as in "300 charge cycles". Typically, that means that you should expect to have to replace your battery every year, after it becomes inefficient.
But you can make a difference in the lifetime of your battery by taking care of it and one of the worst treat it faces is extreme heat. Never leave it close to a heat source or on the dash of your vehicle since heat will greatly affect battery performance.