New batteries often come in a discharged condition and must be charged before use (refer to your manual for charging instructions). Upon initial use (or after a prolonged storage period) the battery may require three to four charge/discharge cycles before achieving maximum capacity.

When charging the battery for the first time your device may indicate that charging is complete after just 10 or 15 minutes. This is a normal phenomenon with rechargeable batteries. Simply remove the battery from the computer and repeat the charging procedure.

It is important to condition (fully discharge and then fully charge) the battery every two to three weeks. Failure to do so may significantly shorten the battery's life (this does not apply to Li-ion batteries, which do not require conditioning). To discharge, simply run your 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 your user’s manual.

If the battery will not be in use for a month or longer, it is recommended that it be removed from the device and stored in a cool, dry, clean place.

It is normal for a battery to become warm during charging and discharging.

A charged battery will eventually lose its charge if unused. It may therefore be necessary to recharge the battery after a storage period.

The milliamp-hour (mAH) rating of the laptop battery will often be higher than the one on your original battery. A higher mAH rating is indicative of a longer lasting (higher capacity) battery and will not cause any incompatibilities. An laptop battery will, in most cases, outperform the original by 30% to 50%.

Actual battery run-time depends upon the power demands made by the equipment. In the case of notebook computers, the use of the monitor, the hard drive and other peripherals results in an additional drain upon the battery, effectively reducing the battery’s run-time. The total run-time of the battery is also heavily dependent upon the design of the equipment. To ensure maximum performance of the battery, optimize your computer's power management features. Refer to your computer manual for further instructions.this from http://www.new-laptop-battery.com