Macbook pro runs out of battery too quickly?

Question

Recently my Macbook Pro (2011, OS 10.9.1) is running out of battery within an hour when it used to have a battery life around 8 hours.
I've copied the battery information below. Please can someone suggest how I solve this? Thanks
Battery Information:
  Model Information:
  Serial Number:          9G039041DD3MA
  Manufacturer:          DP
  Device Name:          bq20z451
  Pack Lot Code:          0
  PCB Lot Code:          0
  Firmware Version:          201
  Hardware Revision:          2
  Cell Revision:          158
  Charge Information:
  Charge Remaining (mAh):          1111
  Fully Charged:          No
  Charging:          No
  Full Charge Capacity (mAh):          4885
  Health Information:
  Cycle Count:          836
  Condition:          Normal
  Battery Installed:          Yes
  Amperage (mA):          -2080
  Voltage (mV):          10813
System Power Settings:
  AC Power:
  System Sleep Timer (Minutes):          0
  Disk Sleep Timer (Minutes):          10
  Display Sleep Timer (Minutes):          3
  Wake on AC Change:          No
  Wake on Clamshell Open:          Yes
  Wake on LAN:          Yes
  Display Sleep Uses Dim:          Yes
  PrioritizeNetworkReachabilityOverSleep:          0
  Battery Power:
  System Sleep Timer (Minutes):          10
  Disk Sleep Timer (Minutes):          10
  Display Sleep Timer (Minutes):          2
  Wake on AC Change:          No
  Wake on Clamshell Open:          Yes
  Current Power Source:          Yes
  Display Sleep Uses Dim:          Yes
  Reduce Brightness:          Yes
Hardware Configuration:
  UPS Installed:          No
AC Charger Information:
  Connected:          No
  Charging:          No

Answer 1

Recharged fully and displaying this:
Battery Information:
  Model Information:
  Serial Number:          9G039041DD3MA
  Manufacturer:          DP
  Device Name:          bq20z451
  Pack Lot Code:          0
  PCB Lot Code:          0
  Firmware Version:          201
  Hardware Revision:          2
  Cell Revision:          158
  Charge Information:
  Charge Remaining (mAh):          4872
  Fully Charged:          Yes
  Charging:          No
  Full Charge Capacity (mAh):          4872
  Health Information:
  Cycle Count:          836
  Condition:          Normal
  Battery Installed:          Yes
  Amperage (mA):          4
  Voltage (mV):          12577
System Power Settings:
  AC Power:
  System Sleep Timer (Minutes):          10
  Disk Sleep Timer (Minutes):          10
  Display Sleep Timer (Minutes):          10
  Wake on AC Change:          No
  Wake on Clamshell Open:          Yes
  Wake on LAN:          Yes
  Current Power Source:          Yes
  Display Sleep Uses Dim:          Yes
  PrioritizeNetworkReachabilityOverSleep:          0
  Battery Power:
  System Sleep Timer (Minutes):          10
  Disk Sleep Timer (Minutes):          10
  Display Sleep Timer (Minutes):          2
  Wake on AC Change:          No
  Wake on Clamshell Open:          Yes
  Display Sleep Uses Dim:          Yes
  Reduce Brightness:          Yes
Hardware Configuration:
  UPS Installed:          No
AC Charger Information:
  Connected:          Yes
  ID:          0x0100
  Wattage (W):          45
  Revision:          0x0000
  Family:          0x00ba
  Serial Number:          0x003e3609
  Charging:          No
I have had my laptop for over 3 years now and has been used well maybe it is near the end of its life