One needs to discharge and recharge a new battery at least 2-4 times for it to reach it’s maximum rated capacity, as most of these new batteries, are not charged. An overnight charge or 12 hours, is a good enough time for your battery. An indication could be the battery getting warm to the touch. When charging the battery for the first time, the device may indicate that charging is complete after just 10 or 15 minutes. This is normal with rechargeable batteries. New batteries are hard for the device to charge; they have never been fully charged and not “broken in.” Sometimes the device’s charger will stop charging a new battery before it is fully charged. If this happens, remove the battery from the device and then reinsert it. The charge cycle should begin again.

Check the “memory effect”
A partially discharged battery at times does not fully discharges before recharging. It sort of “forgets” to do so. This is what is the memory effect. For e.g. if you fully charge your battery and then use only 50% of its capacity before the next recharge, eventually the battery will become unaware of its extra 50% capacity, which has remained unused. The battery will remain functional, but only at 50% of its original capacity. To deal with this, always fully discharge your battery, before recharging it. This can be done by, unplugging the device’s AC adapter and letting the device run on the battery until it ceases to function. This will help your battery remain healthy.

Check the Volts and Milliamp-hours (mAH)
These are ratings on every battery. Milliamp-hours or (mAH), is one-thousandth of an amp-hour (1AH = 1000mAH). The voltage of the new battery should always match the voltage of your original unless the batteries are different chemistries. NiMH and Li-Ion batteries have different voltage ratings, even if they’re for the same device.

Check the discharging time of mobile
Generally, 11/2 – 3 years, or 500-800 charge-discharge cycles. As the rechargeable battery begins to die, there is a decline in the running time of the battery, till it reaches to 50% of its running time, and you need a new battery.

Prevent the Memory Effect – Keep the battery healthy by fully charging and then fully discharging it at least once every two to three weeks. Exceptions to the rule are Li-Ion batteries, which do not suffer from the memory effect. Do not leave the battery dormant for long periods of time.
Always use a battery charger, which is by the same manufacturer as your phone, it gives it more life. It also helps if you overcharge your battery now and then.
Keep the Batteries Clean – It’s a good idea to clean dirty battery contacts with a cotton swab and alcohol. This helps maintain a good connection between the battery and the portable device.
Do not leave your cell phone near any source of heat, a common place being the dashboard of your car, as extreme heat may affect the battery. The battery also operates better at room temperature, vis-à-vis extreme cold.
The vibrator mode of your cell phone consumes more battery, so when not needed, use the ring-tone mode.
Battery Storage – If you don’t plan on using the battery for a month or more, store it in a clean, dry, cool place away from heat and metal objects. Batteries tend to de-charge when not in use, so make sure you charge them again before using. The performance of any cell phone battery, however, no matter how properly cared for, usually diminishes after about a year. It is better to get your battery replaced then.

Battery Do’s:
# Fully charge/discharge battery up to 4 cycles before achieving full capacity of a new battery
# Fully discharge and then fully charge the battery every two to three weeks.
# Run the device under the battery’s power until it shuts down or until you get a low battery warning. Then recharge the battery as instructed in the user’s manual.

# Remove from the device and store in a cool, dry, clean place if the battery will not be in use for a month or longer.
# Recharge the battery after a storage period Ensure maximum performance of the battery by optimizing the device’s power management features. Refer to the manual for further instructions.

Battery Don’ts:
# Do not short-circuit. A short-circuit may cause severe damage to the battery.

# Do not drop, hit or otherwise abuse the battery as this may result in the exposure of the cell contents, which are corrosive.

# Do not expose the battery to moisture or rain.

# Keep battery away from fire or other sources of extreme heat. Do not incinerate. Exposure of battery to extreme heat may result in an explosion