Be productive longer with the HP CO06XL Long Life Slice Notebook Battery, which slides onto the bottom of select HP ProBook 800 series Notebook PC s or select HP Z Books to help you be productive longer than using the primary battery alone. - Use this long-life battery in addition to your primary notebook battery to keep working longer in and out of the office. - Charge the battery when it’s not in use with the included charging dongle that easily connects to your HP notebook’s Smart AC adapter.