For many users, recharging their phone batteries consists of the daily routine of plugging in the charger, and then leaving it on for a couple of hours to juice up. However, depending on your battery type, overcharging or undercharging it could result in a shorter life.

You should also understand that due to the chemical processes involved, batteries deteriorate over time. After a certain number of cycles, the battery's maximum charge capacity drops to below 80 percent of its original capacity.

Battery type Number of charging cycles
Nickel cadmium (NiCd) 1,500
Nickel-metal hydride (NiMH) 300-500
Lithium-ion (Li-ion) 500-1,000
Lithium-polymer (Li-Po) 300-500

Therefore, heavy users who recharge frequently may have to purchase new batteries after a short time compared to light users. However, not every battery will reach this number of cycles before starting to lose charge. For a battery to reach its natural life, proper maintenance is necessary. Batteries may look tough, but they can be inadvertently damaged.

There are several things you can do to maximize the useful life of your battery.

Breaking in
When you first get your battery or phone, you will need to break it in. It may be necessary to fully charge and discharge the battery three to four times before it will be able to make use of its maximum capacity. This is for all battery types.

The first time you charge the battery, the phone may indicate a false full charge after 10 to 15 minutes. This is normal. Unplug and plug the charger to "restart" the charging process.

If you wish to keep your batteries aside for a period, store them in a dry and cool place. Heat and nearby metallic objects can spoil the battery. As the batteries will self-discharge after prolonged storage, you will have to break the batteries in again before use. Having said that, don't leave your rechargeable batteries dormant for extended periods. Cycle them for a full charge and discharge every so often to keep it fresh. Batteries that sit idle for extended periods of time without charging begin tend to lose their ability to hold a charge and will self-discharge.

That thing called "memory effect"
If you do not fully discharge the battery before recharging it, gradually the capacity of the battery will be reduced. This is called the memory effect, and is due to the accumulation of gas bubbles on the cell plates.

NiCad batteries are especially prone to this problem. Therefore users should try to discharge the battery fully after each use, a process called conditioning. NiMH batteries are less susceptible to the memory effect, but even then you should condition them once every one or two weeks. Li-ion and Li-Po batteries are immune from the memory effect.

For optimal talk and standby time in the long run, it is recommended that you use original batteries with your mobile phones.

Most phones beep or display a "Battery Low" message to remind you that the battery will soon need to be charged or replaced with a charged one. If you are desperate to have the phone last just that extra minute longer, you can consider immediately switching to zero ring volume, zero backlight, non-vibration mode, etc. Switching off the phone for a short while can also prolong the remaining standby time when you next switch the phone on.
Thanks
Robert Stevens