Screensaver: Change your laptop's screensaver to a blank (Black) screen,and set it to turn on within a few minutes of inactivity. Screensavers with graphics and sound effects will drain the power more quickly,whereas a blank screen will conserve power.
Hard Drive & Disk Drive: Avoid using the hard drive and disk drive excessively. Because these are mechanical mechanisms,they consume more power. In some cases,upgrading the amount of memory will reduce hard drive usage. If your HP Compaq 6730b laptop is set to run anti-virus scans periodically,only allow this to happen when you have it connected to AC power,because this substantially increases hard drive usage while it is running. If you are using an older laptop with no hard drive,consider using a VDISK or RAMDISK to reduce disk drive usage.
http://www.new-laptopbatteries.com/hp-compaq-6730b.html

Sound/Music: If you want to listen to music while operating the computer,consider using a separate radio,cassette recorder,or CD player. If the CD player's batteries run out,you will be able to keep using the computer,which is probably your higher priority.
USB Devices: If your HP Compaq 6730b laptop computer has a USB port,keep in mind that some USB devices draw power from the computer's battery while they are plugged in to it. Avoid leaving such devices plugged in longer than they need to be.
Software: Different software which accomplishes the same functions may cause your HP Compaq 6730b battery computer to use different amounts of power. If the software utilizes memory more effectively (rather than reading/writing to the disk or hard drive frequently),it may use less power. Software which places less demand on the processor can also reduce power consumption in some cases,along with programs which use a dark-colored background. Avoid running software directly from a 3.5" disk or CD-ROM,because it will cause these mechanisms to run frequently and drain the power more quickly.